@article{YongJacobowitzBaroneetal.1994, author = {Yong, Liu and Jacobowitz, David M. and Barone, Frank and McCarron, Richard and Spatz, Maria and Feuerstein, Giora and Hallenbeck, John M. and Sir{\´e}n, Anna-Leena}, title = {Quantitation of perivascular monocyte / macrophages around cerebral blood vessels of hypertensive and aged rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86800}, year = {1994}, abstract = {The numbers of monocytes and macrophages in the walls of cerebral blood vessels were counted on perfusion-fixed frozen brain sections (16 JLffi) of spontaneously hypertensive rats (SHR), stroke-prone SHR (SHR-SP), normotensive Wistar-Kyoto (WKY) rats, and young (16-week-old) and old (2-year-old) normotensive Sprague-Dawley rats (SD-l6w and SD-2y, respectively) using monoclonal antiborlies against rat macrophages (ED2). The staining was visualized with fluoresceinlabeled second antiborlies. The ED2-specific staining in brain sections was restricted to macrophages in a perivascular location. The number of perivascular cells per square millimeter of high-power field was significantly greater in SHR-SP (8.6 ± 2.1; n = 4) and SHR (6. 7 ± 0.9; n = 6) than in normotensive WKY (4.0 ± 0.5; n = 6; p <0.01). The number of perivascular macrophages was also greater in SD-2y (7.5 ± 2.7; n = 9) than in SD-l6w (2.9 ± 1.8; n = 8; p < 0.01). No ED2 staining was found in the resident microglia or in the endothelial cells, which were identified by double staining with rhodamine-labeled anti-factor VIII-related antigen antiborlies. The results suggest that the stroke risk factors hypertension and advanced age are associated with increased subendothelial accumulation of monocytes and macrophages. This accumulation could increase the tendency for the endothelium to convert from an anticoagulant to a procoagulant surface in response to mediators released from these subendothelial cells.}, subject = {Willebrand-Faktor}, language = {en} } @article{XuNaeveriFrerichsetal.1993, author = {Xu, K. and N{\"a}veri, L. and Frerichs, K. and Hallenbeck, J. M. and Feuerstein, G. and Davis, J. N. and Sir{\´e}n, Anna-Leena}, title = {Extracellular catecholamine levels in rat hippocampus after a selective alpha2-adrenoceptor antagonist or a selective dopamnie uptake inhibitor: Evidence for dopamine release from local dopaminergic nerve terminals}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62997}, year = {1993}, abstract = {The effect of 6-chloro-2,3,4,5-tetrahydro-3-methyi-1-H-3-benzazepine (SKF 86466), a selectlve nonimldazoline alpha-2 adrenoceptor antagonlst, on hippocampal re1ease of norepinephrine and dopamlne in conscious rats was lnvestigated by /n vlvo mlcrodialysis and high-pressure liquid chromatography. Additionally, extracellular concentrations of hippocampal dopamine (DA) and norepinephrtne (NE), durtng Infusion of selective monoamine uptake Inhibitors, were determined in freely moving rats. The basal concentration of NE in the dialysate was 4.9 ± 0.3 pg/20 pl. lntravenous admlnistratlon of 5 or 10 mgJkg of SKF 86466 was associated wlth a transierlt inc:rease (30 min) of 2-fold (12 ± 1 pg/20 ,d; p < .05) and 8-fold (39 ± 3 pg/20 pl; p < .05), respectlvely, in dlalysate NE, whereas a 1-mgfkg dose had no effect. DA was not detected in basal dlalysates, but after the adminlstratlon of 5 or 10 mgJkg of SKF 86466, 3.9 ± 0.4 and 6.4 ± 0.6 pg/20 pl, respectlvely, was present in the dialysates. The rnaxlmum increase in dialysate DA was reached 60 to 90 min after SKF 86466. The DA was not derived from plasma because plasma NE was elevated after the 5 mgJkg dose of SKF 86466 whereas no plasma DA was detected. ln order to determlne whether DA was present in noradrenergic nerve termlnals, the dopamine ß-hydroxylase Inhibitor SKF 1 02698 was administered (50 mgJkg i.p.). The Inhibitor decreased dialysate NE but DA was stin not detected in the dialysate. When SKF 86466 (5 mgJkg t.v.) was adminlstered 4 hr after SKF 102698, DA appeared in the dialysate but there was no lncrease in dialysate NE. Administration through the dialysis probe of the DA uptake Inhibitor, GBR-12909 (0.1 and 1 pM), dose-dependently lnaeased DA Ieveis to 5.7 ± 1.2 and 9.6 ± 2.8 pg/20 pl, respectively. GBR-12909 had no effect on hippocampal NE. Desipramine (5 and 10 pM) lncreased dose-dependently dialysate NE and lncreased DA concentrations to detectable Ieveis (2.7 ± 0.5 and 3.5 ± 0.7 pg/20 ,d, respectively). These results suggest that the a/pha-2 adrenoceptors modulate both NE and DA release in the rat hlppocampus and that DA detected in the hlppocampal dialysate might be released from dopaminergic neurons.}, subject = {Neurobiologie}, language = {en} } @article{WeilandBeezWestermaieretal.2021, author = {Weiland, Judith and Beez, Alexandra and Westermaier, Thomas and Kunze, Ekkehard and Sir{\´e}n, Anna-Leena and Lilla, Nadine}, title = {Neuroprotective strategies in aneurysmal subarachnoid hemorrhage (aSAH)}, series = {International Journal of Molecular Sciences}, volume = {22}, journal = {International Journal of Molecular Sciences}, number = {11}, issn = {1422-0067}, doi = {10.3390/ijms22115442}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260755}, year = {2021}, abstract = {Aneurysmal subarachnoid hemorrhage (aSAH) remains a disease with high mortality and morbidity. Since treating vasospasm has not inevitably led to an improvement in outcome, the actual emphasis is on finding neuroprotective therapies in the early phase following aSAH to prevent secondary brain injury in the later phase of disease. Within the early phase, neuroinflammation, thromboinflammation, disturbances in brain metabolism and early neuroprotective therapies directed against delayed cerebral ischemia (DCI) came into focus. Herein, the role of neuroinflammation, thromboinflammation and metabolism in aSAH is depicted. Potential neuroprotective strategies regarding neuroinflammation target microglia activation, metalloproteases, autophagy and the pathway via Toll-like receptor 4 (TLR4), high mobility group box 1 (HMGB1), NF-κB and finally the release of cytokines like TNFα or IL-1. Following the link to thromboinflammation, potential neuroprotective therapies try to target microthrombus formation, platelets and platelet receptors as well as clot clearance and immune cell infiltration. Potential neuroprotective strategies regarding metabolism try to re-balance the mismatch of energy need and supply following aSAH, for example, in restoring fuel to the TCA cycle or bypassing distinct energy pathways. Overall, this review addresses current neuroprotective strategies in aSAH, hopefully leading to future translational therapy options to prevent secondary brain injury.}, language = {en} } @techreport{WangSirenLiuetal.1994, author = {Wang, X. and Sir{\´e}n, Anna-Leena and Liu, Y. and Yue, T-L. and Barone, F. C. and Feuerstein, G. Z.}, title = {Upregulation of intercellular adhesion molecule-1 (ICAM-1) on brain microvascular endothelial cells in rat ischemic cortex [Research Report]}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62952}, year = {1994}, abstract = {The expression of intercellular adhesion molecule 1 (ICAM-1) was studied in rat focal ischemic cortex. A significant increase in ICAM-1 mRNA expression in the ischemic cortex over Ievels in contralateral (nonischemic) site was observed by means of Northern blot analysis following either permanent or temporary occlusion with reperfusion of the middle cerebral artery (PMCAO or MCAO with reperfusion) in spontaneously hypertensive rats. In the ischemic cortex, Ievels of ICAM-1 mRNA increased significantly at 3 h (2.6-fold, n = 3, P < 0.05), peaked at 6 to 12 h (6.0-fold, P < 0.01) and remained elevated up to 5 days (2.5-fold, P < 0.05) after PMCAO. The profile of ICAM-1 mRNA expression in the ischemic cortex following MCAO with reperfusion was similar to that following PMCAO, except that ICAM-1 mRNA was significantly increased as early as 1 h (6.3-fold, n = 3, P < 0.05) and then gradually reached a peak at 12 h (12-fold, P < 0.01) after reperfusion. ICAM-1 mRNA expression in ischemic cortex following PMCAO was significantly greater in hypertensive rats than in two normotensive rat strains. Immunostaining using anti-ICAM-1 antiborlies indicated that upregulated ICAM-1 expressionwas localized to endotheIial cells of intraparenchymal blood vessels in the ischemic but not contralateral cortex. The data suggest that an upregulation of ICAM-1 mRNA and protein on brain capillary endothelium may play an important rote in leukocyte migration into ischemic brain tissue.}, subject = {Neurobiologie}, language = {en} } @article{VonhofSirenFeuerstein1990, author = {Vonhof, S. and Sir{\´e}n, Anna-Leena and Feuerstein, Giora}, title = {Volume-dependent spatial distribution of microinjected thyrotropin-releasing hormone (TRH) into the medial preoptic nucleus of the rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47421}, year = {1990}, abstract = {The present study was performed to qua ntify the distribution of a peptide neurotransmitter after microinjection into the medial preoptic area (POM), using a technique suitable for conscious animal preparations. The results indicate that only 50-ni volumes of injected tracer were sufficiently localized with 77 ± 9\% recovery in the POM. Injections of higher volumes resulted in an increasing spread of tracer into distant anatomical regions and structures, including the needle tract and cerebral ventricles. The amount of tracer localized in the POM decreased to 38±4\% (200 nl) (P < 0.05) and 41 ±8\% (500 nl) (P <0.05), respectively. The data suggest that the volume of injection is critical for intraparenchymal injections into structures of a diameter of I mm or less, such as the POM and should not exceed 50 nl in conscious animal preparations.}, subject = {Neurophysiologie}, language = {en} } @article{VonhofSirenFeuerstein1991, author = {Vonhof, S. and Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Central ventilatory effects of thyrotropin-releasing hormone in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63075}, year = {1991}, abstract = {Thyrotropin-releasing hormonewas shown to exert potent ventilatory effects after centrat administration. These data, however, were derived from studies using anesthetized animal preparations. Since TRH elicits strong arousal reactions, the observed ventilatory effects of TRH under anesthesia may have been due to nonspecific reduction in the anesthetic state of the animals. In order to clarify the extent to which the reversal of anesthesia may change ventilatory parameters after TRH application, we investigated the effect of TRH on Ventilation rate, relative tidal volume, relative respiratory minute volume, CO\(_2\) production CO\(_2\) consumption, and locomotor activity in the conscious, unrestrained rat. Intracerebroventricular application of TRH induced a dose-dependent, sustained increase in ventilation rate, relative tidal volume, and relative respiratory minute volume of maximally 128\%, 890\%, and 235\%, respectively. In addition, CO\(_2\) production and O\(_2\) consumption were elevated by 4.6 and 11.7 fold, whiJe no significant changes in locomotor activity were observed. The results suggest that TRH stimulates ventilation by a mechanism independent of its analeptic properties.}, subject = {Neurobiologie}, language = {en} } @article{VonhofSiren1991, author = {Vonhof, S. and Sir{\´e}n, Anna-Leena}, title = {Reversal of µ-opioid-mediated respiratory depression by α2-adrenoceptor antagonism}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47454}, year = {1991}, abstract = {The present study was performed in order to evaluate the effects of the selective 02- adrenoceptor antagonist 6-chloro-2,3,4,5-tetrahydro-3-methyl-1H-3-benzazepine (SK\&F 86466) on dermorphin-induced analgesia, respiratory depression and inhibition of locomotor activity in the conscious rat. Intracerebroventricular (icv) administration of dermorphin (3 nmol/rat) decreased respiration rate and relative ventilatory minute volume maximally by 38 \% and 50 \% of baseline respectively. SK\&F 86466 dose-dependently reversed the dermorphin-induced depression of ventilatory parameters, while SK\&F 86466 exerted no effect on dermorphin-induced analgesia or depression of locomotor activity due to catalepsia. It appears, therefore, that a 2-adrenoceptors selectively interact with Jl2-opioid-receptor mediated effects, such as respiratory depression, but are not involved in the modulation of Jl,-opioid-related effects, such as supraspinal analgesia and depression of locomotor activity.}, subject = {Biowissenschaften}, language = {en} } @article{ThomaWischmeyerOffenetal.2012, author = {Thoma, Eva C. and Wischmeyer, Erhard and Offen, Nils and Maurus, Katja and Sir{\´e}n, Anna-Leena and Schartl, Manfred and Wagner, Toni U.}, title = {Ectopic expression of Neurogenin 2 alone is sufficient to induce differentiation of embryonic stem cells into mature neurons}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75862}, year = {2012}, abstract = {Recent studies show that combinations of defined key developmental transcription factors (TFs) can reprogram somatic cells to pluripotency or induce cell conversion of one somatic cell type to another. However, it is not clear if single genes can define a cells identity and if the cell fate defining potential of TFs is also operative in pluripotent stem cells in vitro. Here, we show that ectopic expression of the neural TF Neurogenin2 (Ngn2) is sufficient to induce rapid and efficient differentiation of embryonic stem cells (ESCs) into mature glutamatergic neurons. Ngn2-induced neuronal differentiation did not require any additional external or internal factors and occurred even under pluripotency-promoting conditions. Differentiated cells displayed neuron-specific morphology, protein expression, and functional features, most importantly the generation of action potentials and contacts with hippocampal neurons. Gene expression analyses revealed that Ngn2-induced in vitro differentiation partially resembled neurogenesis in vivo, as it included specific activation of Ngn2 target genes and interaction partners. These findings demonstrate that a single gene is sufficient to determine cell fate decisions of uncommitted stem cells thus giving insights into the role of key developmental genes during lineage commitment. Furthermore, we present a promising tool to improve directed differentiation strategies for applications in both stem cell research and regenerative medicine.}, subject = {Physiologie}, language = {en} } @article{StetterLopezCaperuchipiHoppKraemeretal.2021, author = {Stetter, Christian and Lopez-Caperuchipi, Simon and Hopp-Kr{\"a}mer, Sarah and Bieber, Michael and Kleinschnitz, Christoph and Sir{\´e}n, Anna-Leena and Albert-Weißenberger, Christiane}, title = {Amelioration of cognitive and behavioral deficits after traumatic brain injury in coagulation factor XII deficient mice}, series = {International Journal of Molecular Sciences}, volume = {22}, journal = {International Journal of Molecular Sciences}, number = {9}, issn = {1422-0067}, doi = {10.3390/ijms22094855}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284959}, year = {2021}, abstract = {Based on recent findings that show that depletion of factor XII (FXII) leads to better posttraumatic neurological recovery, we studied the effect of FXII-deficiency on post-traumatic cognitive and behavioral outcomes in female and male mice. In agreement with our previous findings, neurological deficits on day 7 after weight-drop traumatic brain injury (TBI) were significantly reduced in FXII\(^{-/-}\) mice compared to wild type (WT) mice. Also, glycoprotein Ib (GPIb)-positive platelet aggregates were more frequent in brain microvasculature of WT than FXII\(^{-/-}\) mice 3 months after TBI. Six weeks after TBI, memory for novel object was significantly reduced in both female and male WT but not in FXII\(^{-/-}\) mice compared to sham-operated mice. In the setting of automated home-cage monitoring of socially housed mice in IntelliCages, female WT mice but not FXII\(^{-/-}\) mice showed decreased exploration and reacted negatively to reward extinction one month after TBI. Since neuroendocrine stress after TBI might contribute to trauma-induced cognitive dysfunction and negative emotional contrast reactions, we measured peripheral corticosterone levels and the ration of heart, lung, and spleen weight to bodyweight. Three months after TBI, plasma corticosterone levels were significantly suppressed in both female and male WT but not in FXII\(^{-/-}\) mice, while the relative heart weight increased in males but not in females of both phenotypes when compared to sham-operated mice. Our results indicate that FXII deficiency is associated with efficient post-traumatic behavioral and neuroendocrine recovery.}, language = {en} } @article{SirenVonhofFeuerstein1991, author = {Sir{\´e}n, Anna-Leena and Vonhof, S. and Feuerstein, G.}, title = {Hemodynamic defense response to thyrotropin-releasing hormone injected into medial preoptic nucleus in rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63099}, year = {1991}, abstract = {No abstract available}, subject = {Neurobiologie}, language = {en} } @article{SirenSvarstroemFraserPaakkari1985, author = {Sir{\´e}n, Anna-Leena and Svarstr{\"o}m-Fraser, M. and Paakkari, I.}, title = {Central cardiovascular effects of the endoperoxide analogue U-46619 i.c.v. in rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49064}, year = {1985}, abstract = {Thromboxanes are abundantly present in the rat brain but their possible physiological functions in the brain are not known. The prostaglandin endoperoxide analogue U-46619 is a selective agonist of TxA2 receptors in many peripheral tissues. In the present study the ·central cardiovascular and ventilatory effects of U-46619 were investigated in rats. In conscious spontaneously hypertensive rats (SHR) U-46619 (1-100 nmol/kg i.c.v.) induced a strong dose-related increase in blood pressure but had no significant effect on heart rate. In conscious normotensive rats (NR) neither blood pressure nor heart rate was significantly affected. Furthermore, U-46619 (0.1-100 nmol/kg i.c.v.) had no significant effect on blood pressure, heart rate or ventilation in urethane-anaesthetised NR . The results demonstrate an increased sensitivity of SHR to TxA2.}, subject = {Medizin}, language = {en} } @article{SirenStetterHirschbergetal.2013, author = {Sir{\´e}n, Anna-Leena and Stetter, Christian and Hirschberg, Markus and Nieswandt, Bernhard and Ernestus, Ralf-Ingo and Heckmann, Manfred}, title = {An experimental protocol for in vivo imaging of neuronal structural plasticity with 2-photon microscopy in mice}, series = {Experimental \& Translational Stroke Medicine}, journal = {Experimental \& Translational Stroke Medicine}, doi = {10.1186/2040-7378-5-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96908}, year = {2013}, abstract = {Introduction Structural plasticity with synapse formation and elimination is a key component of memory capacity and may be critical for functional recovery after brain injury. Here we describe in detail two surgical techniques to create a cranial window in mice and show crucial points in the procedure for long-term repeated in vivo imaging of synaptic structural plasticity in the mouse neocortex. Methods Transgenic Thy1-YFP(H) mice expressing yellow-fluorescent protein (YFP) in layer-5 pyramidal neurons were prepared under anesthesia for in vivo imaging of dendritic spines in the parietal cortex either with an open-skull glass or thinned skull window. After a recovery period of 14 days, imaging sessions of 45-60 min in duration were started under fluothane anesthesia. To reduce respiration-induced movement artifacts, the skull was glued to a stainless steel plate fixed to metal base. The animals were set under a two-photon microscope with multifocal scanhead splitter (TriMScope, LaVision BioTec) and the Ti-sapphire laser was tuned to the optimal excitation wavelength for YFP (890 nm). Images were acquired by using a 20×, 0.95 NA, water-immersion objective (Olympus) in imaging depth of 100-200 μm from the pial surface. Two-dimensional projections of three-dimensional image stacks containing dendritic segments of interest were saved for further analysis. At the end of the last imaging session, the mice were decapitated and the brains removed for histological analysis. Results Repeated in vivo imaging of dendritic spines of the layer-5 pyramidal neurons was successful using both open-skull glass and thinned skull windows. Both window techniques were associated with low phototoxicity after repeated sessions of imaging. Conclusions Repeated imaging of dendritic spines in vivo allows monitoring of long-term structural dynamics of synapses. When carefully controlled for influence of repeated anesthesia and phototoxicity, the method will be suitable to study changes in synaptic structural plasticity after brain injury.}, language = {en} } @article{SirenPowellFeuerstein1986, author = {Sir{\´e}n, Anna-Leena and Powell, E. and Feuerstein, G.}, title = {Thyrotropin releasing hormone in hypovolemia: a hemodynamic evaluation in the rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63288}, year = {1986}, abstract = {ln the present study the effects of thyrotropin releasing hormone (TRH) and its stable analogue, CG3703, on cardiac output (thermodilution, Cardiomax) and regional blood flow (BF; directional pulsed Doppler technique) were investigated in hypovolemic hypotension in the rat. In urethan-anesthetized rats TRH (0.5 or 2 mg/ kg ia) or CG3703 (0.05 or 0.5 mg/kg ia) reversed the bleeding (27\% of the blood volume)-induced decreases in mean arterial ...}, subject = {Neurobiologie}, language = {en} } @article{SirenPaakkariGoldsteinetal.1989, author = {Sir{\´e}n, Anna-Leena and Paakkari, P. and Goldstein, D. S. and Feuerstein, G.}, title = {Mechanism of central hemodynamic and sympathetic regulation by µ-opioid receptors: Effects of dermorphin in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63123}, year = {1989}, abstract = {The effects of i.c.v. administered dermorphin, a highly selective \(\mu\)-opioid agonist, on cardiac function and renal, mesenteric and hindquarter blood ftow were studied in conscious rats. Core temperature, blood gases, arterial plasma levels of norepinephrine, epinephrine, dopamine, 3,4-dihydroxyphenylalanine and dihydroxyphenylacetic acid (DOPAC) also were examined. Cardiac output was rneasured using a thermodilution technique and regional blood ftows using directional pulsed Doppler velocimetry. Dermorphin, at doses of 0.1-100 nmol/kg, increased blood pressure and hindquarter blood flow, renal and mesenteric resistance, and core temperature. Higher doses (1-5 \(\mu\)mol/kg) caused respiratory depression, acidosis, and shock despite profaund sympatho-adrenomedullary stimulation. Circulating Ieveis of catecholamines were significantly increased at the dermorphin doses of 0.1-1 00 nmol/kg. At the 100 nmol/kg dose, plasma levels of epinephrine, norepinephrine, the dopamine metabellte dihydroxyphenylacetic acid and the catecholamine precursor 3,4,-dihydroxyphenylalanine were increased by 2-15-fold. The data indicate that mu opioid receptor Stimulation exerts potent effects on cardiorespiratory functions, activates the sympathoadrenomedullary system and produces a pattem of blood flow changes consistent with the stress-induced •detense· response (skeletal muscle vasodilation and splanchnic vasoconstriction). Excessive mu opioid receptor Stimulation Ieads to shock due to respiratory and hemodynamic collapse.}, subject = {Neurobiologie}, language = {en} } @article{SirenPaakkari1984, author = {Sir{\´e}n, Anna-Leena and Paakkari, I.}, title = {Cardiovascular effects of TRH i.c.v. in conscious rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49071}, year = {1984}, abstract = {In addition to the endocrine effects, the thyrotropin releasing hormone (TRH) is known to induce dose-dependent increases in blood pressure and heart rate after intracerebroventricular (i.c.v.) administration in urethane-anaesthetised rats (1, 2). The a~ of the present study was to investigate whether TRH has similar effects in conscious rats of various strains i.e. spontaneously hypertensive rats (SHR), normotensive Wistar-Kyoto (WKY) and Wistar (NR) rats.}, subject = {Medizin}, language = {en} } @article{SirenMcCarronLiuetal.1993, author = {Sir{\´e}n, Anna-Leena and McCarron, R. M. and Liu, Y. and Barone, F. and Spatz, M. and Feuerstein, G. and Hallenbeck, J. M.}, title = {Perivascular monocyte/macrophage interaction with endothelium as a mechanism through which stroke-risk factors operate to increase stroke likelihood. Research Initiatives in Vascular Disease; SPECIAL COMMUNICATION}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63006}, year = {1993}, abstract = {No abstract available}, subject = {Neurobiologie}, language = {en} } @article{SirenLettsFeuerstein1988, author = {Sir{\´e}n, Anna-Leena and Letts, G. and Feuerstein, G.}, title = {N-Acetyl-leukotriene E\(_4\) is a potent constrictor of rat mesenteric vessels}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63196}, year = {1988}, abstract = {N-Acetyl-leukotriene E\(_4\) administered to conscious freely moving rats produced a dose-dependent vasoconstriction in the mesenteric vessels which led to profound reduction of blood flow to the gut. Renal and hindquarter blood flow and vascular resistance were not affected even by high doses of N-acetyl-leukotriene E\(_4\) . N-Acetyl-leukotriene E\(_4\) was 10-fold more potent than the thromboxane analog U-46619 and 1000-fold more potent than prostaglandin F\(_{2a}\) but 2-5-fold less potent than leukotriene D\(_4\)/E\(_4\) to induce mesenteric vasoconstriction. These data indicatc that N-acetylleukotriene E\(_4\) is a biologically active metabolite of peptide leukotrienes, and might play a role in cardiovascular derangements mediated by leukotrienes.}, subject = {Neurobiologie}, language = {en} } @article{SirenLakeFeuerstein1988, author = {Sir{\´e}n, Anna-Leena and Lake, C. R. and Feuerstein, G.}, title = {Hemodynamic and neural mechanisms of action of thyrotropin releasing hormone in the rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63183}, year = {1988}, abstract = {Tbe mechanisms mediating the etl'ects ofthyrotropin-releasing hormone (TRH) on the cardiovascular system were studied in the conscious rat. Intracerebroventricolar (i.c. v.) injection of TRH (8 pmol-80 nmollkg) induced dose-dependent lncreases in mean arterial pressure, heart rate, and cardiac index. Rindquarter blood Oow increased due to vasodilation, while an lncrease in renal and mesenteric vascular resistance caused a decrease in blood Oow in the respective organs. The plasma Ievels of norepinephrine a~d epinephrine were increased by TRH, while there was no change in plasma renin activity or vasopressin. Tbe cardiovascular actions of i.c. v. TRH were not in.fluenced by blockade of the renin-angiotensin system or vasopressin receptors. Tbe ganglion blocker chlorisondamine and the a 1- aod al-adrenoreceptor antagooist phentolamlne (2 mg/kg i.v.) abolished the increase in blood pressure and mesenteric vasoconstriction after i.c. v. TRH. Propranolol (2 mg/kg i. v.) blocked the TRH-ioduced increase in cardiac index, heart rate, and hindquarter blood flow. The hindquarter vasodllatlon lnduced by TRH was also blocked by the selective ß1-adrenocept9r antagonist ICI 188,551 (1 or 2 mg/kg i.v.), while tbe ,8,-adrenoceptor blocker practolol (10 mg/kg i.v.) had no eft'ect on the hindquarter vasodiJation produced by TRH but totally blocked the increase in cardiac Index. In adrenal demedullated rats, the systemic hemodynamic eft'ects ofi.c. v. TRH were dimlnished along with the decrease in renal blood flow and lncrease in renal vascular resistance; however, the iocrease in hfndquarter blood flow was attenuated only in adrenal demedullated rats pretreated with the sympathetlc blocker bretylium. The renal vasoconstriction induced by i.c. v. TRH was not abolished by renal denervation. In sinoaortic debufl'ered rats, the pressor, tachycardic, and mesenteric vasoconstrictor responses to centrally administered TRH were significantly potentiated. Taken together, these data soggest that the putative rieurotransmitter TRH may play a role in central regulation of cardiac functions and organ blood flow distribution through both tbe sympathetic nerves and the adrenal medulla. A pivotal roJe for ß1-adrenoceptors in mediation ofhindquarter vasodilation ls also demonstrated.}, subject = {Neurobiologie}, language = {en} } @article{SirenKarppanen1980, author = {Sir{\´e}n, Anna-Leena and Karppanen, H.}, title = {Influence of analgesic antipyretics on the central cardiovascular effects of clonidine in rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-48640}, year = {1980}, abstract = {No abstract available}, subject = {Prostaglandine}, language = {en} } @article{SirenHeldmanDoronetal.1992, author = {Sir{\´e}n, Anna-Leena and Heldman, Eliahu and Doron, David and Yue, Tian-Li and Liu, Yong and Feuerstein, G. and Hallenbeck, JM}, title = {Release of proinflammatory and prothrombbtic mediators in the brain and peripheral circulation in spontaneously hypertensive and normotensive Wistar-Kyoto rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47469}, year = {1992}, abstract = {Background and Purpose: We reported previously that stroke risk factors prepared the brain stem for the development of ischemia and hemorrhage and induced the production of tumor necrosis factor following an intrathecal injection of Iipopolysaccharide, a prototypic monocyte-activating stimulus. This study evaluates whether blood or brain cells of hypertensive rats produce more proinflammatory and prothrombotic mediators than do blood or brain cells of normotensive rats. MethotJs: Levels of tumor necrosis factor, platelet-activating factor, 6-ketoprostaglandin F1a, and thromboxane B2 in the cerebrospinal fluid and blood of spontaneously hypertensive and normotensive Wistar-Kyoto rats were monitored before and after achallenge with Iipopolysaccharide. Results: Little or no activity from these media tors was found in the cerebrospinal fluid or blood of saline-injected control animals. Intravenous administration of Iipopolysaccharide (0.001, 0.1, and 1.8 mg/kg) produced dose-dependent increases in blood levels of all mediators in hypertensive rats. In normotensive rats the levels were less than in hypertensive rats and were not c1early dose-related. When Iipopolysaccharide was injected intracerebroventricularly, more tumor necrosis factor was measured in the cerebrospinal fluid than in the blood, suggesting local synthesis of this cytokine. Levels of tumor necrosis factor and platelet-activating factor in the cerebrospinal fluid were higher in hypertensive than in normotensive rats. The thromboxane A2/prostacyclin ratio was not aItered significantly between the two rat strains. Conclusions: It is suggested that the higher incidence of brain stem ischemia and hemorrhage after the intrathecal injection oflipopolysaccharide in hypertensive rats than in normotensive rats might be related to the higher levels of the two cytotoxic factors tumor necrosis factor and platelet-activating factor produced in response to such challenge.}, subject = {Gehirn}, language = {en} } @article{SirenFeuerstein1987, author = {Sir{\´e}n, Anna-Leena and Feuerstein, Giera}, title = {Central autonomic pharmacology of thyrotropin releasing hormone}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49051}, year = {1987}, abstract = {Thyrotropin releasing hormone (TRH, I-pyroglutamyl-l-histidyl-l-prolinamide) was the fIrst hypothalamic releasing SUbstance to be isolated, chemically characterized and synthetized /1/. The studies to date have revealed that the thyrotropin release from the pituitary gland is only one of the numerous actions of TRH. In addition to its endocrine actions (TSH and prolactin release) this tripeptide has central nervous system actions totally unrelated to its effects on the hypothalamo-pituitary axis. This review aims to summarize the studies on the central nervous system' actions of TRH with special emphasis on the autonomic pharmacology of this peptide.}, subject = {Medizin}, language = {en} } @article{SirenFeuersteinLabrooetal.1986, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G. and Labroo, V. M. and Coleen, L. A. and Lozovsky, D.}, title = {Effect of thyrotropin releasing hormone and some of its histidine analogs on the cardiovascular system and prolactin release in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63307}, year = {1986}, abstract = {The cardiovascular and endocrine activity of three analogs of thyrotropin releasing hor.mone (TRH), 4-nitro-imidazole TRH (4-nitroTRH), 2-trifluoro-methyl-imidazole TRH (2-TFM-TRH) and 4-trifluoromethyl- imidazole TRH (4-TFM-TRH), was compared to TRH in conscious rats. Injection of TRH or the three analogs (1 mg/kg or 5 mg/kg) into the arterial line induced increases in mean arterial pressure, pulse pressure and heart rate and raised plasma prolactin (PRL). None of the analogs were more potent than TRH in inducing cardiovascular changes. The 4-TFM-TRH was significantly less potent than the 2-TFM-TRH in increasing blood pressure, while the nitro-TRH was more potent than the 2-TFM-TRH in producing tachycardia. TRH induced a two-fold increase in PRL at the 5 mg/kg dose, while both the fluorinated analogs elici ted a 4 to 5 fold increase in PRL at the higher dose. The present results suggest that the receptors for TRH-elicited PRL release differ from TRH-receptors involved in its cardiovascular actions.}, subject = {Neurobiologie}, language = {en} } @article{SirenFeuerstein1989, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Effect of PAF and BN 52021 on cardiac function and regional blood flow in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63145}, year = {1989}, abstract = {No abstract available}, subject = {Neurobiologie}, language = {en} } @article{SirenFeuerstein1989, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Thyrotropin releasing hormone-induced hindquarter vasodilation is mediated by \(\beta _2\)-adrenoceptors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63155}, year = {1989}, abstract = {No abstract available}, subject = {Neurobiologie}, language = {en} } @article{SirenFeuerstein1989, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Hemodynamic effects of endothelin after systemic and central nervous System administration in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63165}, year = {1989}, abstract = {No abstract available}, subject = {Neurobiologie}, language = {en} } @article{SirenFeuerstein1988, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Cardiovascular effects of rat calcitonin gene-related peptide in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63236}, year = {1988}, subject = {Neurobiologie}, language = {en} } @article{SirenFeuerstein1986, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Effect of T-2 toxin on regional blood flow and vascular resistance in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63293}, year = {1986}, abstract = {The acute effect ofT-2 toxemia on local blood flow and vascular resistance in hindquarter. mesenteric. and renal vascular beds was continuously measured by the directional pulsed Doppler technique in conscious, male Sprague-Dawley rats. Intravenous injection ofT-2 toxin (I mg/kg) in the conscious rat reduced blood flow and increased vascular resistance in all blood vessels studied but had no significant effect on mean arterial pressure or heart rate. The blood flow in hindquarters gradually decreased to a minimum of -77 ± 9\% (mean ±SE) 6 hr after the toxin injection. The hindquarter vascular resistance concomitantly increased to a maximum value of + 323 ± 69\% above thc resistance before toxin administration. Mesenteric and renal blood flow initially increased (slightly) and then gradually decreased. The maximum drop of blood flow, -90 ± 13\% and -76 ± 13\% for the mesenteric and renal vascular beds, respectively, was achieved 4 hr after T-2 toxin injection and the blood flow values remained low for up to 6 hr. Simultaneously with the impairment of}, subject = {Neurobiologie}, language = {en} } @article{SirenFeuerstein1992, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {The Opioid System in circulatory control}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63045}, year = {1992}, abstract = {Opioid peptidesandmultiple opioid receptors are found in brain cardiovascular nuclei, autonomic ganglia, the heart, and blood vessels, and opioids induce potent cardiovascular changes. The role of endogenaus opioids in normal cardiovascular homeostasis is unclear; however, current data suggest opioid involvement in stress.}, subject = {Neurobiologie}, language = {en} } @article{SirenFeuerstein1991, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Hypothalamic opioid µ-receptors regulate discrete hemodynamic functions in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63069}, year = {1991}, abstract = {The effect of the selective \(\mu\)-opioid agonist o-Ala\(^2\)-Me-Phe\(^4\)-Gly-ol'-enkephalin (DAGO), injected into the medial preoptic nucleus of hypothalamus, on cardiac output and regional blood flow was studied in the conscious rat and the effect of DAGO on renal sympathetic nerve activity and renal blood flow was studied in anesthetized rats. In conscious rats, injections of DAGO (1 or 10 nmol) into the preoptic nucleus increased the blood pressure in a dose-related manner. The maximum rises of mean arterial pressure and pulse pressure after the larger dose were +23 ± 5 mmHg (mean ±SEM, P < 0.01) and + 17 ± 3 mmHg(P < 0.01), respectively. A small dose (0.1 nmol) increased heart rate ( +47 ± 13 bpm, P < 0.05); thc 1 nmol dosc produced bradycardia (- 39 ± 11 bpm, P < 0.05), while the 10 nmol dose initially decreased heart rate ( -68 ± 15 bpm (P < 0.01) and then gradually increased heart rate to a maximum of + 74 ± 13 bpm, (P < 0.0 1). A long-lasting increase in cardiac output was also elicited by DAGO, with maximum changes after 1 and 10 nmol of + 14 ± 6\% and +22 ± 7\% (P < 0.01), respectively. B1ood flow in the hindquarters increascd after DAGO but the mesenteric and renal blood ftow decreased in a dose-related manner. Significant responscs in hindquarter and mesenteric blood fl.ow after DAGO were independent of systemic hemodynamic responses at the dose ofO.l nmol. The vascular resistance in the hindquarters significantly decreased after a small dose of DAGO while the larger doses dose-dependently increased mesenteric and renal vascular resistance. A crucial role of the sympathetic nervous system in the hemodynamic effects of DAGO was demonstrated: (1) by the profound activation of renal sympathetic nerve activity after injections of DAGO (I nmol/100 nl) into the preoptic nucleus, (2) by blockade of the pressor, tachycardic and regional hemodynamic effects of DAGO (I nmol) by the ganglion blocker ch1orisondamine (5 mg/kg i.v.). The results suggest that the pressor effect of DAGO in preoptic nucleus is due primarily to an increase in cardiac output. The differential changes in blood ftow in organs further suggest that the opioid \(\mu\)-receptors in the preoptic nucleus might be involved in the integration of peripheral blood ftow in the hypothalamus during affective behavior.}, subject = {Neurobiologie}, language = {en} } @article{SirenFeuerstein1990, author = {Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Cardiovascular effects of anatoxin-a in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63103}, year = {1990}, abstract = {Cardiovascular Effects of Anatoxin-A in the Conscious Rat. SJREN, A.-L., AND FEUERSTEIN, G. (1990). Toxicol. Appl. Pharmacol. 102,91-100. The effects ofanatoxin-A on mean arterial pressure (MAP), heart rate, cardiac index (CI), and blood flow (BF) in hindquarter (HQ), renal (R). and mesenteric (M) vascular beds were studied after intravenous (iv) and intracerebroventricular (icv) administration in the conscious rat. The pharmacological profile of anatoxin-A was further compared to nicotine administered iv and icv. MAP and heart rate were measured from femoral artery, CI by thermodilution method, and blood flow by Doppler velocimetry. Anatoxin-A and nicotine (30, 100 and 300 1-!g/kg iv) produced an increase in MAP with concomitant bradycardia. The highest doses increased Cl. MBF and RBF decreased due to a vasoconstriction in M and R vasculature. These effects were attenuated by the ganglion blocker chlorisondamine (5 mg/kg, iv). Anatoxin-A ( 100 1-!g/k~ iv) increased plasma epinephrine Ievels by 2- fold with virtually no effect on norepinephrine whereas nicotine ( 100 ~oLg/kg, iv) increased plasma epinephrine and norepinephrine by 20- to 30-fold. Central administration of anatoxin-A and nicotine (30-100 ,ug/kg icv) increased MAP with no effect on heart rate and produced M and R vasoconstriction. In summary, the present study demonstrates that anatoxin-A acts as a nicotinic cholinergic agonist in the c.onscious rat after both systemic and centrat administration. Anatoxin-A and nicotine produced pressor and reno-splanchnic vasoconstrictor responses and at high doses increased cardiac output. These effects were mediated by activation ofthe nicotinic receptors in the adrenal medulla and sympathetic ganglia. However, marked differences were found in the potency ofanatoxin-A versus nicotine to stimulate the sympathoadrenomedullary axis.}, subject = {Neurobiologie}, language = {en} } @article{SirenEimerlFeuerstein1989, author = {Sir{\´e}n, Anna-Leena and Eimerl, J. and Feuerstein, G.}, title = {L-649,923 : An antagonist of cardiac and vascular leukotriene D\(_4\) receptors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63134}, year = {1989}, abstract = {The capacity of L-649,923-sodium ( ßS, -yR * )-4-(3-( 4-acetyl-3-hydroxy-2-propylphenoxy)propylthio)-- y-hydroxy-ß-methylbenzene butanoate-to block vascular receptors of leukotriene D\(_4\) ( L TD\(_4\)) was examined in the conscious rat. Hindquarter (HQ), renal, and mesenteric blood flow and vascular resistance were evaluated in the conscious rat chronically equipped with miniaturized Doppler probes for organ blood flow measurement by directional pulsed Doppler technique. In addition, cardiac outpul was measured by thermodilution technique in conscious rats equipped with minithermistors in the ascending aorta. Systemic hemodynamic variables. mean arterial pressure, and heart rate were monitored through femoral catheters. L TD\(_4\) (I or 10 \(\mu\)g/kg) produced a marked dose dependent increase in the mesenteric vascular resistance associated with a marked decrease in blood flow whereas no consistent effects were demonstrated in the renal circulation. L TD\(_4\) • at I \(\mu\)g/kg. increased the HQ blood flow whereas the higher dose of LTD\(_4\) produced a biphasic response: an early increase followed by a decrease in blood flow. Infusion of L TD\(_4\) • 3 \(\mu\)g/kg per min over 10 min decreased cardiac output and increased total peripheral resistance. L-649,923 (10 or 30 mg/kg, i.v.) effectively blocked the L TD4-induced mesenteric constriction and the second I phase of HQ vasoconstriction but did not modify the , LTD\(_4\) induced HQ vasodilation. L-649,923 also effectively attenuated the cardiac effects of LTD\(_4\) infusion. I These studies suggest that L-649,923 could preserve cardiac and vascular functions in pathologic states mediated by cysteinylleukotrienes, such as traumatic or endotoxin shock. Key Words: Leukotriene D4 -Cardiovascular system- Leukotriene antagonist- Mesenteric blood tlow-Renal blood flow-Hindquarter blood flowAnaphylaxis.}, subject = {Neurobiologie}, language = {en} } @article{Siren1982, author = {Sir{\´e}n, Anna-Leena}, title = {Differences in central actions of arachidonic acid and prostaglandin F\(_{2\alpha}\) between spontaneously hypertensive and normotensive rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63324}, year = {1982}, abstract = {Prostag1andin F\(_{2\alpha}\) (PGF\(_{2\alpha}\)) is one of the most common metabo1ites of arachidonic acid (M) in rat brain. When administered intracerebroventricularly (i.c.v.) to rats, both AA and PGFal exert dose-related hypertensive, tachycardic and hyperthermic effects. Metabolie alterations in the endogenaus formation of some prostaglandins in the brain-stem of spontaneously hypertensive rats (SHR) have been reported. Therefore the central effects of AA and PGF \(_{2\alpha}\) on blood pressure, heart rate and body temperature were studied both in SHR and nonootensive Wistar rats (NR) under urethane-anaesthesia. The hypertensive effect of AA i.c.v. (0.01-100 \(\mu\)g/rat) was larger in magni tude in SHR than in NR, but there was no significant difference in the M-induced changes of heart rate and body temperature between the groups. Pretreatment of NR wi th soditm1 :meclofenamate (1 mg/rat i.c.v.) antagonised the central effects of M indicating that these effects are not due to M itself but to its conversion to prostaglandins. Unlike the effects of AA, the central hypertensive, tachycardic and hyperthennic responses to PGF\(_{2\alpha}\) (0.5-50 l-lg/rat i.c.v .) were significantly attenuated in SHR. The present results obtained with M are conpatible with the previous assumption that the synthesis of prostaglandins in the brain of SHR might differ from that in NR. The results also demonstrate that the central effects of PGF\(_{2\alpha}\) are reduced in SHR.}, subject = {Neurobiologie}, language = {en} } @article{Siren1988, author = {Sir{\´e}n, Anna-Leena}, title = {Cardiovascular pharmacology of thyrotropin releasing hormone}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63214}, year = {1988}, subject = {Neurobiologie}, language = {en} } @article{Siren1982, author = {Sir{\´e}n, Anna-Leena}, title = {Central cardiovascular and thermal effects of Prostaglandin E2 in rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47960}, year = {1982}, abstract = {Prostaglandin E2 (PGE2) increased the blood pressure, heart rate and body temperature, when administered at the doses ofO.OOI-IO,ug into the lateral cerebral ventricle (i.c.v.) of the urethane-anesthetised rat. The highest dose of 10 ,ug/rat induced a strong initial hypotensive effect. lntravenously (i.v.), PGE2 at the doses of 0.01-10 ,ug/rat caused a biphasic blood pressure response with dose-related initial decreases followed by slight increases in blood pressure. The heart rate and body temperature were slightly increased by i.v. administrations of PGE2 . The highest i.v. dose of 10 ,ug/rat initially decreased also the heart rate. Central pretreatment with indomethacin ( I mg/rat i.c.v.) partly antagonised all of the recorded central effects of PGE2 , while sodium meclofenamate (I mg/rat i.c. v.) abolished the hypertensive response to i.c. v. administered PGE2 but failed to significantly affect the PGE2-induced rises of heart rate and body temperature. The results support the previous suggestions that PGE2 may participate in the central cardiovascular and thermoregulatory contro!. The results also suggest that indomethacin and sodium meclofenamate antagonize the effects of exogenous prostaglandins. Since sodium meclofenamate, unlike indomethacin, affected preferentially the hypertensive response to centrally administered PGE2 , there may be differences in the sites and/or modes of action between these drugs.}, subject = {Physiologie}, language = {en} } @article{Siren1981, author = {Sir{\´e}n, Anna-Leena}, title = {Central cardiovascular and thermal effects of prostacyclin in rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47943}, year = {1981}, abstract = {Prostacyclin (PGI2) induced a dose-dependent decrease in blood pressure with slight increases in heart rate and body temperature, when administered at the doses of 0.1-100 ~g into the lateral cerebral ventricle (i.c.v.) of the urethane-anaesthetised rat. When the same doses were administered intravenously, both the blood pressure and heart rate decreased. Central pretreatment wib~ sodiurn meclofenamate (1 mg/rat i.c.v.) antagonised the central hypotensive effect of PGI2 but i.c.v. pretreatrnent of the rats with indomethacin (1 mg/rat) failed to affect the PGI 2-induced hypotension. Central pretreatment with two histamine H2-receptor antagonists, cimetidine (500 ~g/rat i.c.v.) or metiamide (488 ~g/rat i.c.v.), antagonised the blood pressure lowering effect of 0.1 ~g dose of PGI2 but failed to affect the hypotension induced by higher PGI2 doses. Therefore the main central hypotensive effect of PGI2 seems not to be associated with the stimulation of histamine H2 -receptors in the brain. The hypotensive effect of i.c.v. administered PGI2 appears to be due to an action upon the central nervous system rather than to a leakage into the peripheral circulation. This assurnption is supported by the fact that sodiurn meclofenamate i.c.v. antagonised the effect of PGI 2. In addition, the chronotropic response to i.c.v. PGI2 was opposite to that induced by intravenous administration. The results also suggest that there may be differences in the mode of action between sodiurn meclofenamate and indomethacin.}, subject = {Prostaglandine}, language = {en} } @article{Siren1982, author = {Sir{\´e}n, Anna-Leena}, title = {Central cardiovascular and thermal effects of prostaglandin D2 in rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-48658}, year = {1982}, abstract = {Prostaglandin D2 (PGD2) is the most common prostaglandin type of tile rat brain. Recently a neurornodulator role for PGD2 has been suggested. In the present work the central cardiovascular and thermal effects of PGDz were studied in urethane-anaesthetised rats. Mlen adrndnistered at the doses of 0.001-10 ~g/rat into the lateral cerebral ventricle(i.c.v.), PGD2 slightly increased the blood pressure, heart rate and body ternpera~ ure. The highest dose caused also an initial hypotensive effect. Upon lntravenous injections PGD2 (0.1-10 ~g/rat) initially decreased and then weakly increased the blood pressure but had only negligible effects on heart rate and body temperature. Central pretreatment with sodium meclofenamate or indomethacin (1 mg/rat i.c.v.) antagonised effectively all the recorded central effects of PGD2. The central cardiovascular and thermal effects of PGD2 were much weaker than those obtained earlier with other prostaglandins, such as PGF2alpha and PGE2.. Therefore, in spite of its abundance in the brain PGD2 may not be very important for the central cardiovascular and thermal regulation in the rat.}, subject = {Medizin}, language = {en} } @article{SirenLiuFeuersteinetal.1993, author = {Sir{\`e}n, Anna-Leena and Liu, Y. and Feuerstein, G. and Hallenbeck, JM}, title = {Increased release of tumor necrosis factor alpha into the cerebrospinal fluid and peripheral circulation of aged rats}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47997}, year = {1993}, abstract = {Background and Purpose: We earlier reported that risk factors for stroke prepare brain stem tissue for a modified Shwartzman reaction, incIuding the development of ischemia and hemorrhage and the production of tumor necrosis factor-a, after a provocative dose of lipopolysaccharide. In the present study, we sought to determine whether blood and central nervous system cells of rats with the stroke risk factor of advanced age produce more proinflammatory and prothrombotic media tors than do those of young rats of the same strain. Methods: Levels of tumor necrosis factor-a and platelet activating factor in the cerebrospinal fluid and tumor necrosis factor-a in the serum of 2-year-old and 16-week-old Sprague-Dawley rats were monitored before and after challenge with lipopolysaccharide. Results: No consistent tumor necrosis factor-a activity was found in the cerebrospinal fluid or blood of control animals. Intravenous administration of lipopolysaccharide (1.8 mg/kg) increased serum tumor necrosis factor-a levels but had no effect on tumor necrosis factor-a in the cerebrospinal fluid. Serum tumor necrosis factor-a increased much more in aged rats than in young rats. When lipopolysaccharide was injected intracerebroventricularly, tumor necrosis factor-a activity in cerebrospinal fluid increased significantly more in old rats than in young rats. Baseline levels of platelet activating factor in cerebrospinal fluid were significantly higher in old rats than in young rats, and the levels increased to a greater degree in aged rats on stimulation. Conclusions: Rats with the stroke risk factor of advanced age respond to lipopolysaccharide with a more exuberant production of tumor necrosis factor-a and platelet activating factor than young rats of the same strain. These findings are consistent with our working hypothesis that perivascular cells are capable of exaggerated signaling of endothelium through cytokines such as tumor necrosis factor-a in animals with stroke risk factors. The effect of such signaling might be to prepare the endothelium of the local vascular segment for thrombosis or hemorrhage in accord with the local Shwartzman reaction paradigm.}, subject = {Gehirn}, language = {en} } @article{ShuaibXuCrainetal.1990, author = {Shuaib, A. and Xu, K. and Crain, B. and Sir{\´e}n, Anna-Leena and Feuerstein, Giora and Hallenbeck, J. and Davis, JN}, title = {Assessment of damage from implantation of microdialysis probes in the rat hippocampus with silver degeneration staining}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47433}, year = {1990}, abstract = {We used a sensitive silver degeneration staining method to study the effects of insertion of microdialysis probes in rat dorsal hippocampus and neocortex. Nine animals were sacrificed 24 h, 3 days or 7 days after implantation of dialysis tubing. Although mild neuronal cell death and small petechial hemorrhages were seen in elose proximity to the implantation site, the striking finding was the presence of degenerating axons both adjacent to the implantation site and in remote sites such as the corpus callosum and contralateral hippocampus. The observed changes could alter brain function near or remote from the implantation site and should be considered in analysis of dialysis experiments.}, subject = {Neurophysiologie}, language = {en} } @article{SchwinnMokhtariThuseketal.2021, author = {Schwinn, Stefanie and Mokhtari, Zeinab and Thusek, Sina and Schneider, Theresa and Sir{\´e}n, Anna-Leena and Tiemeyer, Nicola and Caruana, Ignazio and Miele, Evelina and Schlegel, Paul G. and Beilhack, Andreas and W{\"o}lfl, Matthias}, title = {Cytotoxic effects and tolerability of gemcitabine and axitinib in a xenograft model for c-myc amplified medulloblastoma}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-93586-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261476}, year = {2021}, abstract = {Medulloblastoma is the most common high-grade brain tumor in childhood. Medulloblastomas with c-myc amplification, classified as group 3, are the most aggressive among the four disease subtypes resulting in a 5-year overall survival of just above 50\%. Despite current intensive therapy regimens, patients suffering from group 3 medulloblastoma urgently require new therapeutic options. Using a recently established c-myc amplified human medulloblastoma cell line, we performed an in-vitro-drug screen with single and combinatorial drugs that are either already clinically approved or agents in the advanced stage of clinical development. Candidate drugs were identified in vitro and then evaluated in vivo. Tumor growth was closely monitored by BLI. Vessel development was assessed by 3D light-sheet-fluorescence-microscopy. We identified the combination of gemcitabine and axitinib to be highly cytotoxic, requiring only low picomolar concentrations when used in combination. In the orthotopic model, gemcitabine and axitinib showed efficacy in terms of tumor control and survival. In both models, gemcitabine and axitinib were better tolerated than the standard regimen comprising of cisplatin and etoposide phosphate. 3D light-sheet-fluorescence-microscopy of intact tumors revealed thinning and rarefication of tumor vessels, providing one explanation for reduced tumor growth. Thus, the combination of the two drugs gemcitabine and axitinib has favorable effects on preventing tumor progression in an orthotopic group 3 medulloblastoma xenograft model while exhibiting a favorable toxicity profile. The combination merits further exploration as a new approach to treat high-risk group 3 medulloblastoma.}, language = {en} } @article{SchmittEckardtSchlegeletal.2015, author = {Schmitt, Jessica and Eckardt, Sigrid and Schlegel, Paul G and Sir{\´e}n, Anna-Leena and Bruttel, Valentin S and McLaughlin, K John and Wischhusen, J{\"o}rg and M{\"u}ller, Albrecht M}, title = {Human parthenogenetic embryonic stem cell-derived neural stem cells express HLA-G and show unique resistance to NK cell-mediated killing}, series = {Molecular Medicine}, volume = {21}, journal = {Molecular Medicine}, number = {2101185}, doi = {10.2119/molmed.2014.00188}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149170}, pages = {185-196}, year = {2015}, abstract = {Parent-of-origin imprints have been implicated in the regulation of neural differentiation and brain development. Previously we have shown that, despite the lack of a paternal genome, human parthenogenetic (PG) embryonic stem cells (hESCs) can form proliferating neural stem cells (NSCs) that are capable of differentiation into physiologically functional neurons while maintaining allele-specific expression of imprinted genes. Since biparental ("normal") hESC-derived NSCs (N NSCs) are targeted by immune cells, we characterized the immunogenicity of PG NSCs. Flow cytometry and immunocytochemistry revealed that both N NSCs and PG NSCs exhibited surface expression of human leukocyte antigen (HLA) class I but not HLA-DR molecules. Functional analyses using an in vitro mixed lymphocyte reaction assay resulted in less proliferation of peripheral blood mononuclear cells (PBMC) with PG compared with N NSCs. In addition, natural killer (NK) cells cytolyzed PG less than N NSCs. At a molecular level, expression analyses of immune regulatory factors revealed higher HLA-G levels in PG compared with N NSCs. In line with this finding, MIR152, which represses HLA-G expression, is less transcribed in PG compared with N cells. Blockage of HLA-G receptors ILT2 and KIR2DL4 on natural killer cell leukemia (NKL) cells increased cytolysis of PG NSCs. Together this indicates that PG NSCs have unique immunological properties due to elevated HLA-G expression.}, language = {en} } @article{RaslanAlbertWeissenbergerErnestusetal.2012, author = {Raslan, Furat and Albert-Weißenberger, Christiane and Ernestus, Ralf-Ingo and Kleinschnitz, Christoph and Sir{\´e}n, Anna-Leena}, title = {Focal brain trauma in the cryogenic lesion model in mice}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75419}, year = {2012}, abstract = {The method to induce unilateral cryogenic lesions was first described in 1958 by Klatzo. We describe here an adaptation of this model that allows reliable measurement of lesion volume and vasogenic edema by 2, 3, 5-triphenyltetrazolium chloride-staining and Evans blue extravasation in mice. A copper or aluminium cylinder with a tip diameter of 2.5 mm is cooled with liquid nitrogen and placed on the exposed skull bone over the parietal cortex (coordinates from bregma: 1.5 mm posterior, 1.5 mm lateral). The tip diameter and the contact time between the tip and the parietal skull determine the extent of cryolesion. Due to an early damage of the blood brain barrier, the cryogenic cortical injury is characterized by vasogenic edema, marked brain swelling, and inflammation. The lesion grows during the first 24 hours, a process involving complex interactions between endothelial cells, immune cells, cerebral blood flow, and the intracranial pressure. These contribute substantially to the damage from the initial injury. The major advantage of the cryogenic lesion model is the circumscribed and highly reproducible lesion size and location.}, subject = {Medizin}, language = {en} } @article{PauliPaulProppertetal.2021, author = {Pauli, Martin and Paul, Mila M. and Proppert, Sven and Mrestani, Achmed and Sharifi, Marzieh and Repp, Felix and K{\"u}rzinger, Lydia and Kollmannsberger, Philip and Sauer, Markus and Heckmann, Manfred and Sir{\´e}n, Anna-Leena}, title = {Targeted volumetric single-molecule localization microscopy of defined presynaptic structures in brain sections}, series = {Communications Biology}, volume = {4}, journal = {Communications Biology}, doi = {10.1038/s42003-021-01939-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259830}, pages = {407}, year = {2021}, abstract = {Revealing the molecular organization of anatomically precisely defined brain regions is necessary for refined understanding of synaptic plasticity. Although three-dimensional (3D) single-molecule localization microscopy can provide the required resolution, imaging more than a few micrometers deep into tissue remains challenging. To quantify presynaptic active zones (AZ) of entire, large, conditional detonator hippocampal mossy fiber (MF) boutons with diameters as large as 10 mu m, we developed a method for targeted volumetric direct stochastic optical reconstruction microscopy (dSTORM). An optimized protocol for fast repeated axial scanning and efficient sequential labeling of the AZ scaffold Bassoon and membrane bound GFP with Alexa Fluor 647 enabled 3D-dSTORM imaging of 25 mu m thick mouse brain sections and assignment of AZs to specific neuronal substructures. Quantitative data analysis revealed large differences in Bassoon cluster size and density for distinct hippocampal regions with largest clusters in MF boutons. Pauli et al. develop targeted volumetric dSTORM in order to image large hippocampal mossy fiber boutons (MFBs) in brain slices. They can identify synaptic targets of individual MFBs and measured size and density of Bassoon clusters within individual untruncated MFBs at nanoscopic resolution.}, language = {en} } @article{PaulMiedenLeferingetal.2023, author = {Paul, Mila M. and Mieden, Hannah J. and Lefering, Rolf and Kupczyk, Eva K. and Jordan, Martin C. and Gilbert, Fabian and Meffert, Rainer H. and Sir{\´e}n, Anna-Leena and Hoelscher-Doht, Stefanie}, title = {Impact of a femoral fracture on outcome after traumatic brain injury — a matched-pair analysis of the TraumaRegister DGU\(^®\)}, series = {Journal of Clinical Medicine}, volume = {12}, journal = {Journal of Clinical Medicine}, number = {11}, issn = {2077-0383}, doi = {10.3390/jcm12113802}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319363}, year = {2023}, abstract = {Traumatic brain injury (TBI) is the leading cause of death and disability in polytrauma and is often accompanied by concomitant injuries. We conducted a retrospective matched-pair analysis of data from a 10-year period from the multicenter database TraumaRegister DGU\(^®\) to analyze the impact of a concomitant femoral fracture on the outcome of TBI patients. A total of 4508 patients with moderate to critical TBI were included and matched by severity of TBI, American Society of Anesthesiologists (ASA) risk classification, initial Glasgow Coma Scale (GCS), age, and sex. Patients who suffered combined TBI and femoral fracture showed increased mortality and worse outcome at the time of discharge, a higher chance of multi-organ failure, and a rate of neurosurgical intervention. Especially those with moderate TBI showed enhanced in-hospital mortality when presenting with a concomitant femoral fracture (p = 0.037). The choice of fracture treatment (damage control orthopedics vs. early total care) did not impact mortality. In summary, patients with combined TBI and femoral fracture have higher mortality, more in-hospital complications, an increased need for neurosurgical intervention, and inferior outcome compared to patients with TBI solely. More investigations are needed to decipher the pathophysiological consequences of a long-bone fracture on the outcome after TBI.}, language = {en} } @article{PaakkariPaakkariVonhofetal.1993, author = {Paakkari, P. and Paakkari, I. and Vonhof, S. and Feuerstein, G. and Sir{\´e}n, Anna-Leena}, title = {Dermorphin analog Tyr-D-Arg\(^2\)-Phe-sarcosine-induces opioid analgesia and respiratory stimulation - the role of Mu\(_1\)- receptors?}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62984}, year = {1993}, abstract = {Tyr-o-Arg\(^2\)-Phe-sarcosine\(^4\) (TAPS), a mu-selective tetrapeptide analog of dermorphin, induced sustained antinociception and stimulated ventilatory minute volume (MV) at the doses of 3 to 100 pmol i.c.v. The doses of 30 and 100 pmol i.c.v. induced catalepsy. The effect of TAPS on MV was in negative correlation with the dose and the maximal response was achieved by the lowest (3 pmol) dose (+63 ± 23\%, P < .05). Morphine, an agonist at both mu\(_1\) and mu\(_2\) sites, at a dose of 150 nmol i.c.v. (equianalgetic to 100 pmol of TAPS decreased the MV by 30\%, due to a decrease in ventilatory tidal volume. The antinociceptive effect of TAPS was antagonized by naloxone and the mu, receptor antagonist, naloxonazine. Naloxonazine also attenuated the catalepsy produced by 1 00 pmol of TAPS i.c. v. and the respiratory Stimulation produced by 3 pmol of TAPS i.c.v. Pretreatment with 30 pmol of TAPS antagonized the respiratory depression induced by the mu opioid agonist dermorphin (changes in MV after dermorphin alone at 1 or 3 nmol were -22 ± 1 0\% and -60 ± 9\% and, after pretreatment with TAPS, +44 ± 11 \% and -18 ± 5\%, respectively). After combined pretreatment with naloxonazine and TAPS, 1 nmol of dermorphin had no significant effect on ventilation. In contrast, pretreatment with a low respiratory stimulant dose (10 pmol i.c.v.) of dermorphin did not modify the effect of 1 nmol of dermorphin. ln conclusion, the antinociceptive, cataleptic and respiratory stimulant effects of TAPS appear to be a related to its agonist action at the mu, opioid receptors. TAPS did not induce respiratory depression (a mu\(_2\) opioid effect) but antagonized the respiratory depressant effect of another mu agonist. Thus, in vivo TAPS appears to act as a mu\(_2\) receptor antagonist.}, subject = {Neurobiologie}, language = {en} } @article{PaakkariPaakkariSirenetal.1990, author = {Paakkari, P. and Paakkari, I. and Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Respiratory and locomotor stimulation by low doses of dermorphin - a Mu\(_1\)-receptor mediated effect}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63110}, year = {1990}, abstract = {The selective opioid mu receptor agonist dermorphin increased the locomotor activity of rats dose dependently at 1 0 to 1 00 pmol/kg i.c.v. Respiratory rate, relative tidal volume and respiratory minute volume also increased unrelated to changes in locomotor activity. Higher doses, on the other hand, produced catalepsy and respiratory depression. Pretreatment of the rats with the mu,-selective antagonist naloxonazine (10 mg/kg i.v.) blocked the stimulant locomotor and respiratory effects of low doses of dermorphin (1 0--1 00 pmol/kg), but potentiated the respiratory depressant effect of a high dose (1 0 nmol/kg) of dermorphin. The selective benzodiazepine antagonist flumazenil (5 mg/kg), which has been shown previously to antagonize catalepsy and respiratory depression produced by relatively high doses of dermorphin, did not antagonize the respiratory or locomotor stimulant effect of dermorphin. The data suggest that mu\(_1\)-opioid receptors are responsible for the low dose stimulant effects of dermorphin on locomotor activity and respiration whereas mu\(_2\) receptors mediate the respiratory depressant effect of dermorphin.}, subject = {Neurobiologie}, language = {en} } @article{PaakkariPaakkariLandesetal.1993, author = {Paakkari, P. and Paakkari, I. and Landes, P. and Sir{\´e}n, Anna-Leena and Feuerstein, G.}, title = {Respiratory \(\mu\)-Opioid and benzodiazepine interactions in the understrained rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62974}, year = {1993}, abstract = {lnteractions of p-opioid receptors with the benzodiazepine system were studied by examining the modulatory effects of flumazenil (a benzodiazepine antagonist) and alprazolam (a benzodiazepine agonist) on the respiratory effects ofthe opioid peptide dermorphin. Dermorphin, 1-30 nmol administered i.c.v., to conscious, unrestrained rats decreased ventilation rate (VR) and minute volume (MV) dose-dependently. The ventilatory depression was antagonized by naloxone and by the benzodiazepine antagonist flumazenil. The benzodiazepine alprazolam potentiateri the respiratory inhibition of a small (I nmol) dose of dermorphin but antagonized that of a higher dos:~ (3 nmol). The results suggest that the benzodiazepine/GABA receptor complex modulates respiratory depression induced by centrat p-receptor Stimulation in the rat.}, subject = {Neurobiologie}, language = {en} } @article{PaakkariPaakkariFeuersteinetal.1992, author = {Paakkari, P. and Paakkari, I. and Feuerstein, G. and Sir{\´e}n, Anna-Leena}, title = {Evidence for differential opioid µ\(_1\)- and µ\(_2\)-receptor regulation of heart rate in the conscious rat}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63017}, year = {1992}, abstract = {The possibility that \(\mu\)Opioid-induced tachycardia and bradycardia could be mediated by different subtypes of the \(\mu\)·receptor was studied in conscious Sprague-Dawley rats. The selective \(\mu\)·receptor agonist dermorphin and its analog, TAPS (Tyr-o-Arg-Phe-sarcosine), a putative \(\mu _1\)-receptor agonist, were given centrally. Tyr-o-Arg-Phe-sarcosine increased the heart rate, the response being inversely correlated to the dose (an increase of 71 ± 22, 49 ± 14 and 30 ± 17 beats/min at doses of 0.3, 3 and 30 pmol, respectively). Dermorphin induced less clear changes in heart rate (maximum increase of 39 ± 14 beats/min at the dose of 1 pmol). Aftertreatment with the Jl 1-selective antagonist naloxonazine (NAZ), TAPS 30 pmol and dennorphin I pmol decreased heart rate by -22 ± 10 and -24 ± 7 bpm, respectively. The bradycardic effect oflarger doses of dennorphin was potentiated by NAZ (from -25 ± 8 to -97 ± 22 bpm) but abolished by the non-selective antagonist naloxone. These data suggest that the high affinity \(\mu _1\)-opioid receptors mediate tachycardic responses and \(\mu _2\)-receptors mediate bradycardic responses.}, subject = {Neurobiologie}, language = {en} } @article{PaakkariSirenNurminenetal.1987, author = {Paakkari, I. and Sir{\´e}n, Anna-Leena and Nurminen, M.-L. and Svartstr{\"o}m-Fraser, M.}, title = {Injection of thyrotropin releasing hormone into the locus coeruleus increases blood pressure}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72894}, year = {1987}, abstract = {Thyrotropin releasing hormone (TRH), 10 pmol kg-1 injected in the region of locus coeruleus, caused a rapid (within 1 min) rise of mean arterial pressure in the urethane- naesthetized rat. No clear-cut effects in heart rate or ventilation were observed. When TRH was injected into the lateral ventricle, a dose more than 10-fold higher was required to achieve a comparable rise in arterial pressure. It is concluded that TRH may have a physiological rote in centrat cardiovascular regulation.}, subject = {Thyreotropin-Releasinghormon}, language = {en} } @article{PaakkariNurminenSiren1986, author = {Paakkari, I. and Nurminen, M-L. and Sir{\´e}n, Anna-Leena}, title = {Cardioventilatory effects of TRH in anesthetized rats: role of the brainstem}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63277}, year = {1986}, abstract = {Cardioventilator responses were studied in anaesthetized rats after injections of TRH into either the lateral (i.c.v. lat) or the fourth (i.c.v. IV) cerebral ventricles. TRH induced a morerapid hypertensive effect i.c.v. IV than i.c.v. lat. Blocking of the cerebral aqueduct abolished the hypertensive and tachypnoeic effects of TRH i.c.v. lat but not those of TRH i.c.v. IV. It is concluded that TRH increased blood pressure and ventilation rate via brain stem structures close to the fourtli ventricle.}, subject = {Neurobiologie}, language = {en} } @article{MrestaniPauliKollmannsbergeretal.2021, author = {Mrestani, Achmed and Pauli, Martin and Kollmannsberger, Philip and Repp, Felix and Kittel, Robert J. and Eilers, Jens and Doose, S{\"o}ren and Sauer, Markus and Sir{\´e}n, Anna-Leena and Heckmann, Manfred and Paul, Mila M.}, title = {Active zone compaction correlates with presynaptic homeostatic potentiation}, series = {Cell Reports}, volume = {37}, journal = {Cell Reports}, number = {1}, doi = {10.1016/j.celrep.2021.109770}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265497}, pages = {109770}, year = {2021}, abstract = {Neurotransmitter release is stabilized by homeostatic plasticity. Presynaptic homeostatic potentiation (PHP) operates on timescales ranging from minute- to life-long adaptations and likely involves reorganization of presynaptic active zones (AZs). At Drosophila melanogaster neuromuscular junctions, earlier work ascribed AZ enlargement by incorporating more Bruchpilot (Brp) scaffold protein a role in PHP. We use localization microscopy (direct stochastic optical reconstruction microscopy [dSTORM]) and hierarchical density-based spatial clustering of applications with noise (HDBSCAN) to study AZ plasticity during PHP at the synaptic mesoscale. We find compaction of individual AZs in acute philanthotoxin-induced and chronic genetically induced PHP but unchanged copy numbers of AZ proteins. Compaction even occurs at the level of Brp subclusters, which move toward AZ centers, and in Rab3 interacting molecule (RIM)-binding protein (RBP) subclusters. Furthermore, correlative confocal and dSTORM imaging reveals how AZ compaction in PHP translates into apparent increases in AZ area and Brp protein content, as implied earlier.}, language = {en} }