@article{ChenBoettgerReifetal.2010, author = {Chen, Yong and Boettger, Michael K. and Reif, Andreas and Schmitt, Angelika and Ueceyler, Nurcan and Sommer, Claudia}, title = {Nitric oxide synthase modulates CFA-induced thermal hyperalgesia through cytokine regulation in mice}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68349}, year = {2010}, abstract = {Background: Although it has been largely demonstrated that nitric oxide synthase (NOS), a key enzyme for nitric oxide (NO) production, modulates inflammatory pain, the molecular mechanisms underlying these effects remain to be clarified. Here we asked whether cytokines, which have well-described roles in inflammatory pain, are downstream targets of NO in inflammatory pain and which of the isoforms of NOS are involved in this process. Results: Intraperitoneal (i.p.) pretreatment with 7-nitroindazole sodium salt (7-NINA, a selective neuronal NOS inhibitor), aminoguanidine hydrochloride (AG, a selective inducible NOS inhibitor), L-N(G)-nitroarginine methyl ester (L-NAME, a non-selective NOS inhibitor), but not L-N(5)-(1-iminoethyl)-ornithine (L-NIO, a selective endothelial NOS inhibitor), significantly attenuated thermal hyperalgesia induced by intraplantar (i.pl.) injection of complete Freund's adjuvant (CFA). Real-time reverse transcription-polymerase chain reaction (RT-PCR) revealed a significant increase of nNOS, iNOS, and eNOS gene expression, as well as tumor necrosis factor-alpha (TNF), interleukin-1 beta (IL-1b), and interleukin-10 (IL-10) gene expression in plantar skin, following CFA. Pretreatment with the NOS inhibitors prevented the CFA-induced increase of the pro-inflammatory cytokines TNF and IL-1b. The increase of the antiinflammatory cytokine IL-10 was augmented in mice pretreated with 7-NINA or L-NAME, but reduced in mice receiving AG or L-NIO. NNOS-, iNOS- or eNOS-knockout (KO) mice had lower gene expression of TNF, IL-1b, and IL-10 following CFA, overall corroborating the inhibitor data. Conclusion: These findings lead us to propose that inhibition of NOS modulates inflammatory thermal hyperalgesia by regulating cytokine expression.}, subject = {Medizin}, language = {en} } @article{GutknechtPoppWaideretal.2015, author = {Gutknecht, Lise and Popp, Sandy and Waider, Jonas and Sommerlandt, Frank M. J. and G{\"o}ppner, Corinna and Post, Antonia and Reif, Andreas and van den Hove, Daniel and Strekalova, Tatyana and Schmitt, Angelika and Colaςo, Maria B. N. and Sommer, Claudia and Palme, Rupert and Lesch, Klaus-Peter}, title = {Interaction of brain 5-HT synthesis deficiency, chronic stress and sex differentially impact emotional behavior in Tph2 knockout mice}, series = {Psychopharmacology}, volume = {232}, journal = {Psychopharmacology}, doi = {10.1007/s00213-015-3879-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-154586}, pages = {2429 -- 2441}, year = {2015}, abstract = {Rationale While brain serotonin (5-HT) function is implicated in gene-by-environment interaction (GxE) impacting the vulnerability-resilience continuum in neuropsychiatric disorders, it remains elusive how the interplay of altered 5-HT synthesis and environmental stressors is linked to failure in emotion regulation. Objective Here, we investigated the effect of constitutively impaired 5-HT synthesis on behavioral and neuroendocrine responses to unpredictable chronic mild stress (CMS) using a mouse model of brain 5-HT deficiency resulting from targeted inactivation of the tryptophan hydroxylase-2 (Tph2) gene. Results Locomotor activity and anxiety- and depression-like behavior as well as conditioned fear responses were differentially affected by Tph2 genotype, sex, and CMS. Tph2 null mutants (Tph2\(^{-/-}\)) displayed increased general metabolism, marginally reduced anxiety- and depression-like behavior but strikingly increased conditioned fear responses. Behavioral modifications were associated with sex-specific hypothalamic-pituitary-adrenocortical (HPA) system alterations as indicated by plasma corticosterone and fecal corticosterone metabolite concentrations. Tph2\(^{-/-}\) males displayed increased impulsivity and high aggressiveness. Tph2\(^{-/-}\) females displayed greater emotional reactivity to aversive conditions as reflected by changes in behaviors at baseline including increased freezing and decreased locomotion in novel environments. However, both Tph2\(^{-/-}\) male and female mice were resilient to CMS-induced hyperlocomotion, while CMS intensified conditioned fear responses in a GxE-dependent manner. Conclusions Our results indicate that 5-HT mediates behavioral responses to environmental adversity by facilitating the encoding of stress effects leading to increased vulnerability for negative emotionality.}, language = {en} } @article{SchaefferKuehnSchmittetal.2013, author = {Schaeffer, Evelin L. and K{\"u}hn, Franziska and Schmitt, Angelika and Gattaz, Wagner F. and Gruber, Oliver and Schneider-Axmann, Thomas and Falkai, Peter and Schmitt, Andrea}, title = {Increased cell proliferation in the rat anterior cingulate cortex following neonatal hypoxia: relevance to schizophrenia}, series = {Journal of Neural Transmission}, volume = {120}, journal = {Journal of Neural Transmission}, number = {1}, doi = {10.1007/s00702-012-0859-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125890}, pages = {187-195}, year = {2013}, abstract = {As a consequence of obstetric complications, neonatal hypoxia has been discussed as an environmental factor in the pathophysiology of schizophrenia. However, the biological consequences of hypoxia are unclear. The neurodevelopmental hypothesis of schizophrenia suggests that the onset of abnormal brain development and neuropathology occurs perinatally, whereas symptoms of the disease appear in early adulthood. In our animal model of chronic neonatal hypoxia, we have detected behavioral alterations resembling those known from schizophrenia. Disturbances in cell proliferation possibly contribute to the pathophysiology of this disease. In the present study, we used postnatal rats to investigate cell proliferation in several brain areas following neonatal hypoxia. Rats were repeatedly exposed to hypoxia (89 \% N2, 11 \% O2) from postnatal day (PD) 4-8. We then evaluated cell proliferation on PD 13 and 39, respectively. These investigations were performed in the anterior cingulate cortex (ACC), caudate-putamen (CPU), dentate gyrus, and subventricular zone. Rats exposed to hypoxia exhibited increased cell proliferation in the ACC at PD 13, normalizing at PD 39. In other brain regions, no alterations have been detected. Additionally, hypoxia-treated rats showed decreased CPU volume at PD 13. The results of the present study on the one hand support the assumption of chronic hypoxia influencing transient cell proliferation in the ACC, and on the other hand reveal normalization during ageing.}, language = {en} } @article{GutknechtAraragiMerkeretal.2012, author = {Gutknecht, Lise and Araragi, Naozumi and Merker, S{\"o}ren and Waider, Jonas and Sommerlandt, Frank M. J. and Mlinar, Boris and Baccini, Gilda and Mayer, Ute and Proft, Florian and Hamon, Michel and Schmitt, Angelika G. and Corradetti, Renato and Lanfumey, Laurence and Lesch, Klaus-Peter}, title = {Impacts of Brain Serotonin Deficiency following Tph2 Inactivation on Development and Raphe Neuron Serotonergic Specification}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {8}, doi = {10.1371/journal.pone.0043157}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133728}, year = {2012}, abstract = {Brain serotonin (5-HT) is implicated in a wide range of functions from basic physiological mechanisms to complex behaviors, including neuropsychiatric conditions, as well as in developmental processes. Increasing evidence links 5-HT signaling alterations during development to emotional dysregulation and psychopathology in adult age. To further analyze the importance of brain 5-HT in somatic and brain development and function, and more specifically differentiation and specification of the serotonergic system itself, we generated a mouse model with brain-specific 5-HT deficiency resulting from a genetically driven constitutive inactivation of neuronal tryptophan hydroxylase-2 (Tph2). Tph2 inactivation (Tph2-/-) resulted in brain 5-HT deficiency leading to growth retardation and persistent leanness, whereas a sex- and age-dependent increase in body weight was observed in Tph2+/- mice. The conserved expression pattern of the 5-HT neuron-specific markers (except Tph2 and 5-HT) demonstrates that brain 5-HT synthesis is not a prerequisite for the proliferation, differentiation and survival of raphe neurons subjected to the developmental program of serotonergic specification. Furthermore, although these neurons are unable to synthesize 5-HT from the precursor tryptophan, they still display electrophysiological properties characteristic of 5-HT neurons. Moreover, 5-HT deficiency induces an up-regulation of 5-HT\(_{1A}\) and 5-HT\(_{1B}\) receptors across brain regions as well as a reduction of norepinephrine concentrations accompanied by a reduced number of noradrenergic neurons. Together, our results characterize developmental, neurochemical, neurobiological and electrophysiological consequences of brain-specific 5-HT deficiency, reveal a dual dose-dependent role of 5-HT in body weight regulation and show that differentiation of serotonergic neuron phenotype is independent from endogenous 5-HT synthesis.}, language = {en} } @article{FreyPoppPostetal.2014, author = {Frey, Anna and Popp, Sandy and Post, Antonia and Langer, Simon and Lehmann, Marc and Hofmann, Ulrich and Siren, Anna-Leena and Hommers, Leif and Schmitt, Angelika and Strekalova, Tatyana and Ertl, Georg and Lesch, Klaus-Peter and Frantz, Stefan}, title = {Experimental heart failure causes depression-like behavior together with differential regulation of inflammatory and structural genes in the brain}, series = {Frontiers in Behavioral Neuroscience}, volume = {8}, journal = {Frontiers in Behavioral Neuroscience}, issn = {1662-5153}, doi = {10.3389/fnbeh.2014.00376}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-118234}, pages = {376}, year = {2014}, abstract = {Background: Depression and anxiety are common and independent outcome predictors in patients with chronic heart failure (CHF). However, it is unclear whether CHF causes depression. Thus, we investigated whether mice develop anxiety- and depression-like behavior after induction of ischemic CHF by myocardial infarction (MI). Methods and Results: In order to assess depression-like behavior, anhedonia was investigated by repeatedly testing sucrose preference for 8 weeks after coronary artery ligation or sham operation. Mice with large MI and increased left ventricular dimensions on echocardiography (termed CHF mice) showed reduced preference for sucrose, indicating depression-like behavior. 6 weeks after MI, mice were tested for exploratory activity, anxiety-like behavior and cognitive function using the elevated plus maze (EPM), light-dark box (LDB), open field (OF), and object recognition (OR) tests. In the EPM and OF, CHF mice exhibited diminished exploratory behavior and motivation despite similar movement capability. In the OR, CHF mice had reduced preference for novelty and impaired short-term memory. On histology, CHF mice had unaltered overall cerebral morphology. However, analysis of gene expression by RNA-sequencing in prefrontal cortical, hippocampal, and left ventricular tissue revealed changes in genes related to inflammation and cofactors of neuronal signal transduction in CHF mice, with Nr4a1 being dysregulated both in prefrontal cortex and myocardium after MI. Conclusions: After induction of ischemic CHF, mice exhibited anhedonic behavior, decreased exploratory activity and interest in novelty, and cognitive impairment. Thus, ischemic CHF leads to distinct behavioral changes in mice analogous to symptoms observed in humans with CHF and comorbid depression.}, language = {en} } @article{BonnSchmittAsan2012, author = {Bonn, Maria and Schmitt, Angelika and Asan, Esther}, title = {Double and triple in situ hybridization for coexpression studies: combined fluorescent and chromogenic detection of neuropeptide Y (NPY) and serotonin receptor subtype mRNAs expressed at different abundance levels}, series = {Histochemistry and Cell Biology}, volume = {137}, journal = {Histochemistry and Cell Biology}, number = {1}, doi = {10.1007/s00418-011-0882-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126720}, pages = {11-24}, year = {2012}, abstract = {Multiple fluorescence in situ hybridization is the method of choice for studies aimed at determining simultaneous production of signal transduction molecules and neuromodulators in neurons. In our analyses of the monoamine receptor mRNA expression of peptidergic neurons in the rat telencephalon, double tyramide-signal-amplified fluorescence in situ hybridization delivered satisfactory results for coexpression analysis of neuropeptide Y (NPY) and serotonin receptor 2C (5-HT2C) mRNA, a receptor subtype expressed at high-to-moderate abundance in the regions analyzed. However, expression of 5-HT1A mRNA, which is expressed at comparatively low abundance in many telencephalic areas, could not be unequivocally identified in NPY mRNA-reactive neurons due to high background and poor signal-to-noise ratio in fluorescent receptor mRNA detections. Parallel chromogenic in situ hybridization provided clear labeling for 5-HT1A mRNA and additionally offered the possibility to monitor the chromogen deposition at regular time intervals to determine the optimal signal-to-noise ratio. We first developed a double labeling protocol combining fluorescence and chromogenic in situ hybridization and subsequently expanded this variation to combine double fluorescence and chromogenic in situ hybridization for triple labelings. With this method, we documented expression of 5-HT2C and/or 5-HT1A in subpopulations of telencephalic NPY-producing neurons. The method developed in the present study appears suitable for conventional light and fluorescence microscopy, combines advantages of fluorescence and chromogenic in situ hybridization protocols and thus provides a reliable non-radioactive alternative to previously published multiple labeling methods for coexpression analyses in which one mRNA species requires highly sensitive detection.}, language = {en} } @article{BonnSchmittAsan2012, author = {Bonn, Maria and Schmitt, Angelika and Asan, Esther}, title = {Double and triple in situ hybridization for coexpression studies: combined fluorescent and chromogenic detection of neuropeptide Y (NPY) and serotonin receptor subtype mRNAs expressed at different abundance levels}, series = {Histochemistry and Cell Biology}, volume = {137}, journal = {Histochemistry and Cell Biology}, number = {1}, doi = {10.1007/s00418-011-0882-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127080}, pages = {11-24}, year = {2012}, abstract = {Multiple fluorescence in situ hybridization is the method of choice for studies aimed at determining simultaneous production of signal transduction molecules and neuromodulators in neurons. In our analyses of the monoamine receptor mRNA expression of peptidergic neurons in the rat telencephalon, double tyramide-signal-amplified fluorescence in situ hybridization delivered satisfactory results for coexpression analysis of neuropeptide Y (NPY) and serotonin receptor 2C (5-HT2C) mRNA, a receptor subtype expressed at high-to-moderate abundance in the regions analyzed. However, expression of 5-HT1A mRNA, which is expressed at comparatively low abundance in many telencephalic areas, could not be unequivocally identified in NPY mRNA-reactive neurons due to high background and poor signal-to-noise ratio in fluorescent receptor mRNA detections. Parallel chromogenic in situ hybridization provided clear labeling for 5-HT1A mRNA and additionally offered the possibility to monitor the chromogen deposition at regular time intervals to determine the optimal signal-to-noise ratio. We first developed a double labeling protocol combining fluorescence and chromogenic in situ hybridization and subsequently expanded this variation to combine double fluorescence and chromogenic in situ hybridization for triple labelings. With this method, we documented expression of 5-HT2C and/or 5-HT1A in subpopulations of telencephalic NPY-producing neurons. The method developed in the present study appears suitable for conventional light and fluorescence microscopy, combines advantages of fluorescence and chromogenic in situ hybridization protocols and thus provides a reliable non-radioactive alternative to previously published multiple labeling methods for coexpression analyses in which one mRNA species requires highly sensitive detection.}, language = {en} } @article{BonnSchmittAsan2011, author = {Bonn, Maria and Schmitt, Angelika and Asan, Esther}, title = {Double and triple in situ hybridization for coexpression studies: combined fluorescent and chromogenic detection of neuropeptide Y (NPY) and serotonin receptor subtype mRNAs expressed at different abundance levels}, series = {Histochemistry and Cell Biology}, volume = {137}, journal = {Histochemistry and Cell Biology}, number = {1}, doi = {10.1007/s00418-011-0882-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-135229}, pages = {Nov 24}, year = {2011}, abstract = {Multiple fluorescence in situ hybridization is the method of choice for studies aimed at determining simultaneous production of signal transduction molecules and neuromodulators in neurons. In our analyses of the monoamine receptor mRNA expression of peptidergic neurons in the rat telencephalon, double tyramide-signal-amplified fluorescence in situ hybridization delivered satisfactory results for coexpression analysis of neuropeptide Y (NPY) and serotonin receptor 2C (5-HT2C) mRNA, a receptor subtype expressed at high-to-moderate abundance in the regions analyzed. However, expression of 5-HT1A mRNA, which is expressed at comparatively low abundance in many telencephalic areas, could not be unequivocally identified in NPY mRNA-reactive neurons due to high background and poor signal-to-noise ratio in fluorescent receptor mRNA detections. Parallel chromogenic in situ hybridization provided clear labeling for 5-HT1A mRNA and additionally offered the possibility to monitor the chromogen deposition at regular time intervals to determine the optimal signal-to-noise ratio. We first developed a double labeling protocol combining fluorescence and chromogenic in situ hybridization and subsequently expanded this variation to combine double fluorescence and chromogenic in situ hybridization for triple labelings. With this method, we documented expression of 5-HT2C and/or 5-HT1A in subpopulations of telencephalic NPY-producing neurons. The method developed in the present study appears suitable for conventional light and fluorescence microscopy, combines advantages of fluorescence and chromogenic in situ hybridization protocols and thus provides a reliable non-radioactive alternative to previously published multiple labeling methods for coexpression analyses in which one mRNA species requires highly sensitive detection.}, language = {en} } @article{VandenHoveJakobSchrautetal.2011, author = {Van den Hove, Daniel and Jakob, Sissi Brigitte and Schraut, Karla-Gerlinde and Kenis, Gunter and Schmitt, Angelika Gertrud and Kneitz, Susanne and Scholz, Claus-J{\"u}rgen and Wiescholleck, Valentina and Ortega, Gabriela and Prickaerts, Jos and Steinbusch, Harry and Lesch, Klaus-Peter}, title = {Differential Effects of Prenatal Stress in 5-Htt Deficient Mice: Towards Molecular Mechanisms of Gene x Environment Interactions}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75795}, year = {2011}, abstract = {Prenatal stress (PS) has been shown to influence the development of the fetal brain and to increase the risk for the development of psychiatric disorders in later life. Furthermore, the variation of human serotonin transporter (5-HTT, SLC6A4) gene was suggested to exert a modulating effect on the association between early life stress and the risk for depression. In the present study, we used a 5-Htt6PS paradigm to investigate whether the effects of PS are dependent on the 5-Htt genotype. For this purpose, the effects of PS on cognition, anxiety- and depression-related behavior were examined using a maternal restraint stress paradigm of PS in C57BL6 wild-type (WT) and heterozygous 5-Htt deficient (5-Htt +/2) mice. Additionally, in female offspring, a genome-wide hippocampal gene expression profiling was performed using the Affymetrix GeneChipH Mouse Genome 430 2.0 Array. 5-Htt +/2 offspring showed enhanced memory performance and signs of reduced anxiety as compared to WT offspring. In contrast, exposure of 5-Htt +/2 mice to PS was associated with increased depressive-like behavior, an effect that tended to be more pronounced in female offspring. Further, 5-Htt genotype, PS and their interaction differentially affected the expression of numerous genes and related pathways within the female hippocampus. Specifically, MAPK and neurotrophin signaling were regulated by both the 5-Htt +/2 genotype and PS exposure, whereas cytokine and Wnt signaling were affected in a 5-Htt genotype6PS manner, indicating a gene6environment interaction at the molecular level. In conclusion, our data suggest that although the 5-Htt +/2 genotype shows clear adaptive capacity, 5-Htt +/2 mice -particularly females- at the same time appear to be more vulnerable to developmental stress exposure when compared to WT offspring. Moreover, hippocampal gene expression profiles suggest that distinct molecular mechanisms mediate the behavioral effects of the 5-Htt genotype, PS exposure, and their interaction.}, subject = {Medizin}, language = {en} } @article{VandenHoveJakobSchrautetal.2011, author = {Van den Hove, Daniel and Jakob, Sissi Brigitte and Schraut, Karla-Gerlinde and Kenis, Gunter and Schmitt, Angelika Gertrud and Kneitz, Susanne and Scholz, Claus-J{\"u}rgen and Wiescholleck, Valentina and Ortega, Gabriela and Prickaerts, Jos and Steinbusch, Harry and Lesch, Klaus-Peter}, title = {Differential Effects of Prenatal Stress in 5-Htt Deficient Mice: Towards Molecular Mechanisms of Gene x Environment Interactions}, series = {PLoS ONE}, volume = {6}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0022715}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-135111}, pages = {e22715}, year = {2011}, abstract = {Prenatal stress (PS) has been shown to influence the development of the fetal brain and to increase the risk for the development of psychiatric disorders in later life. Furthermore, the variation of human serotonin transporter (5-HTT, SLC6A4) gene was suggested to exert a modulating effect on the association between early life stress and the risk for depression. In the present study, we used a 5-HttxPS paradigm to investigate whether the effects of PS are dependent on the 5-Htt genotype. For this purpose, the effects of PS on cognition, anxiety-and depression-related behavior were examined using a maternal restraint stress paradigm of PS in C57BL6 wild-type (WT) and heterozygous 5-Htt deficient (5-Htt +/-) mice. Additionally, in female offspring, a genome-wide hippocampal gene expression profiling was performed using the Affymetrix GeneChip (R) Mouse Genome 430 2.0 Array. 5-Htt +/- offspring showed enhanced memory performance and signs of reduced anxiety as compared to WT offspring. In contrast, exposure of 5-Htt +/- mice to PS was associated with increased depressive-like behavior, an effect that tended to be more pronounced in female offspring. Further, 5-Htt genotype, PS and their interaction differentially affected the expression of numerous genes and related pathways within the female hippocampus. Specifically, MAPK and neurotrophin signaling were regulated by both the 5-Htt +/- genotype and PS exposure, whereas cytokine and Wnt signaling were affected in a 5-Htt genotypexPS manner, indicating a genexenvironment interaction at the molecular level. In conclusion, our data suggest that although the 5-Htt +/- genotype shows clear adaptive capacity, 5-Htt +/- mice -particularly females-at the same time appear to be more vulnerable to developmental stress exposure when compared to WT offspring. Moreover, hippocampal gene expression profiles suggest that distinct molecular mechanisms mediate the behavioral effects of the 5-Htt genotype, PS exposure, and their interaction.}, language = {en} }