TY  - JOUR
A1  - Chen, Y.
A1  - Palm, F.
A1  - Lesch, K. P.
A1  - Gerlach, M.
A1  - Moessner, R.
A1  - Sommer, C.
T1  - 5-hydroxyindolacetic acid (5-HIAA), a main metabolite of serotonin, is responsible for complete Freund's adjuvant-induced thermal hyperalgesia in mice
N2  - Background: The role of serotonin (5-hydroxytrptamine, 5-HT) in the modulation of pain has been widely studied. Previous work led to the hypothesis that 5-hydroxyindolacetic acid (5-HIAA), a main metabolite of serotonin, might by itself influence pain thresholds. Results: In the present study, we investigated the role of 5-HIAA in inflammatory pain induced by intraplantar injection of complete Freund’s adjuvant (CFA) into the hind paw of mice. Wild-type mice were compared to mice deficient of the 5-HT transporter (5-HTT-/- mice) using behavioral tests for hyperalgesia and high-performance liquid chromatography (HPLC) to determine tissue levels of 5-HIAA. Wild-type mice reproducibly developed thermal hyperalgesia and paw edema for 5 days after CFA injection. 5-HTT-/- mice treated with CFA had reduced thermal hyperalgesia on day 1 after CFA injection and normal responses to heat hereafter. The 5-HIAA levels in spinal cord and sciatic nerve as measured with HPLC were lower in 5-HTT-/- mice than in wild-type mice after CFA injection. Pretreatment of wild-type mice with intraperitoneal injection of para-chlorophenylalanine (p-CPA), a serotonin synthesis inhibitor, resulted in depletion of the 5-HIAA content in spinal cord and sciatic nerve and decrease in thermal hyperalgesia in CFA injected mice. The application of exogenous 5-HIAA resulted in potentiation of thermal hyperalgesia induced by CFA in 5-HTT-/- mice and in wild-type mice pretreated with p- CPA, but not in wild-type mice without p-CPA pretreatment. Further, methysergide, a broad-spectrum serotonin receptor antagonist, had no effect on 5-HIAA-induced potentiation of thermal hyperalgesia in CFA-treated wildtype mice. Conclusion: Taken together, the present results suggest that 5-HIAA plays an important role in modulating peripheral thermal hyperalgesia in CFA induced inflammation, probably via a non-serotonin receptor mechanism.
KW  - Medizin
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68858
ER  - 
TY  - THES
A1  - Dang, Su-Yin Judith
T1  - Funktionelle Bedeutung der Neuroplastizität bei Multipler Sklerose
T1  - The functional relevance of neuronal plasticity in multiple sclerosis
N2  - Die Multiple Sklerose ist eine chronische neurologische Erkrankung, welche in der industrialisierten Welt einen der häufigsten Gründe für eine bleibende Behinderung bei jungen Erwachsenen darstellt. Obwohl die ZNS-Schädigung, charakterisiert durch Demyelinisierung und axonale Schädigung im Rahmen entzündlicher Vorgänge, durch verschiedene Reparaturmechanismen reduziert wird, akkumuliert die Läsionslast im zentralen Nervensystem mit der Zeit. T2-gewichtete MRT-Studien zeigen, dass die dargestellten Pathologien nur mäßig mit den motorischen Defiziten korrelieren. Diese Diskrepanz wird unter anderem auf Vorgänge der Neuroplastizität zurückgeführt, als deren Basismechanismen Langzeitpotenzierung (LTP) und -depression (LTD) gelten. In verschiedenen fMRT-Studien haben sich Hinweise ergeben, dass diese adaptiven Veränderungen zur Reorganisation kortikaler Repräsentationmuster führen können, so dass bei MS-Patienten eine ausgedehntere Aktivierung ipsilateraler sensomotorischer Areale bei motorischen Aufgaben zu beobachten ist. Die transkranielle Magnetstimulation (TMS) bietet die Möglichkeit, mittels virtueller Läsionstechniken eine direkte Aussage über die kausale Beziehung zwischen Struktur und Funktion zu liefern. Die funktionelle Rolle ipsilateraler Motorareale wurde an 26 MS-Patienten, in Relation zu ihrer motorischen Beeinträchtigung und ZNS-Schädigung, und an nach Alter, Geschlecht und Händigkeit zugeordneten Kontrollprobanden, untersucht. Die motorische Leistungsfähigkeit wurde durch verschiedene Tests zur Handfunktion erhoben. Die ZNS-Schädigung wurde mittels MR-Spektroskopie als NAA/Cr Quotient sowie durch die CML erhoben. Die Aufgabe zur einfachen Reaktionszeit (SRT) bestand aus einer isometrischen Abduktionsbewegung des rechten Daumens gegen einen Kraftaufnehmer auf ein akustisches Go-Signal. Mit TMS-Einzelreizen wurde mit Hilfe einer Neuronavigation eine reversible virtuelle Läsion über bestimmten Gehirnarealen, kontralateraler M1, ipsilateraler M1 und ipsilateraler PMd, erzeugt. Es wurde eine Kontrollstimulation über MO durchgeführt. Die TMS-Einzelreize wurden 100ms nach dem Go-Signal appliziert. Als SRT wurde der Zeitraum zwischen dem Go-Signal und EMG-Beginn im APB definiert. Die signifikanten SRT-Verlängerungen bei TMS über dem ipsilateralen M1 und dem ipsilateralen PMd zeigen, dass diese Regionen eine Rolle bei der motorischen Funktion bei MS spielen. Die fehlenden Korrelationen zwischen motorischen Funktionstest und NAA/Cr-Verhältnis sowie die inverse Korrelation zur kortikomuskulären Latenz sind durch strukturell von der krankheitsbedingten Pathologie betroffenen kompensierenden Gehirnregionen erklärbar. Bei dem Theta Burst Experiments (TBS) wurde ein virtueller Läsionseffekt durch eine repetitive TMS-Intervention über dem ipsilateralen M1 induziert. Die Ergebnisse zeigen ähnliche Veränderungen der Exzitabilität bei MS-Patienten und gesunden Kontrollprobanden, was schließen lässt, dass die LTD bei mild bis moderat betroffenen MS-Patienten weitestgehend unbeeinträchtigt ist. MS-Patienten zeigen im Vergleich zu den Kontrollen eine ähnliche Minderung der Verhaltensleistung, Trefferquote in ein Kraftfenster, der MS-Patienten im Kontrollvergleich. Die Ergebnisse zeigen, dass ipsilaterale motorische Areale in der Lage sind den primär motorischen Kortex soweit zu kompensieren, jedoch die Fähigkeit zur Kompensation in fortgeschrittenen Krankheitsstadien eingeschränkt ist. Abschließend kann man zusammenfassen, dass die funktionelle Rekrutierung von ipsilateralen Motorarealen eine adaptive Antwort auf chronische Gehirnschädigung bei MS-Patienten sein kann, allerdings mit Einschränkung der Kapazität in fortgeschrittenen Krankheitsstadien. Nachdem die synaptische Plastizität weitestgehend intakt scheint, sollte man besonders Mechanismen der späten Phase der Plastizität fördern, welche auf eine langfristige kortikale Plastizität abzielen. Weitere Studien in diesem Forschungszweig könnten einen Beitrag zur Entwicklung therapeutischer Konzepte der Neurorehabilitation bei Multipler Sklerose leisten.
N2  - Multiple Sclerosis is a chronic neurological disease, which is one of the common reasons in the industrial world causing a lasting disablement at young adults. Despite of reduction by several mechanisms the cns injury characterized by demyelinizing and axonal injury in order of inflammatory processes the lesion load of the cns accumulates over the years. T2-weighted MRI studies only show moderate correlations between the represented pathologies and the motoric deficits. This discrepancy is attributed i.a. to procedures of neuroplasticity whose basic mechanisms are considered as Long-term potentiation (LTP) and -depression (LTD). Several fMRI studies suggest a reogranization of cortical representative pattern due to these adaptive changes. Therefore an extended activation of ipilaterale sensomotoric areas is observed in MS patients performing motoric tasks. Transcranial Magnetic Stimulation (TMS) provides via lesional techniques the possibility of a direct conclusion causal link to structure and function. The functional role of ipsilateral motor areas has been examined in 26 MS patients in relation to their motor impairment and cns injury. Healthy controls were matched for age, sex and handedness. The motor performance was assessed by a test battery of hand function. The cns injury was evaluated using magnetic resonance spectroscopy (NAA/Cr Quotient) and TMS (CML). The Simple Reaction Time task (SRT) consisted of a brisk isometric abduction of the right thumb against a force transducer as a respond to an auditorily Go-Signal. With the help of a neuronavigational device a reversible virtual lesion, delivered by TMS single pulses, were applied to specific brain areas, contralateral M1, ipsilateral M1 and ipsilateral PMD. A control stimulation were assessed to MO??. TMS Single pulses were applied 100ms after Go-Signal. SRT were defined as the time between Go-Signal and EMG onset. Significant extention of SRT after TMS to ipsilateral M1 and ipsilateral PMd evidence the role of these regions in motoric function in MS. The missing correlation between motor performance and NAA/Cr Quotient as well as the inverse correlation to CML are explainable by compensation brain regions which are themselves structurally affected by disease pathologies. In the Thetaburs experiments (TBS) a virtual lesion was induced by a repetitive TMS intervention to ipsilateral M1. The results show a similar change of excitability in MS patients and healthy controls which concludes that LTD is not compromised in mild to moderate affected MS patients. MS patients presented in comparison to controlls a similiar discrease of behavioral performance, hit rate in a force range. The results evidence that ipsilateral motor areas have the ability to compensate the primary motor cortex. But the ability for compensation is limited in advanced stages of illness. The concluding summary is that functional recruitment of ipsilateral motor areas are adaptive response to chronic brain injury in MS patients but with limited capacity in advanced stages of illness. As the synaptic plasticity seem intact to the greatest possible extent mechanism of the late stadium of plasticity should be supported which aim at long term cortical plasticity. Further studies in this branch of research could contribute the development of therapeutic concepts of neurorehabilitation in MS.
KW  - Neuronale Plastizität
KW  - Multiple Sklerose
KW  - Transkranielle Magnetstimulation
KW  - neuronal plasticity
KW  - multiple sclerosis
KW  - transcranial magnetic stimulation
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73817
ER  - 
TY  - JOUR
A1  - Ueceyler, Nurcan
A1  - Biko, Lydia
A1  - Sommer, Claudia
T1  - MDL-28170 Has No Analgesic Effect on CCI Induced Neuropathic Pain in Mice
N2  - The calpain inhibitor MDL-28710 blocks the early local pro-inflammatory cytokine gene expression in mice after chronic constriction nerve injury (CCI). Onehundred- thirteen wild type mice of C57Bl/6J background received CCI of the right sciatic nerve. Mechanical paw withdrawal thresholds and thermal withdrawal latencies were investigated at baseline and at 1, 3, and 7 days after CCI. Three application regimens were used for MDL-28170: a) single injection 40 min before CCI; b) serial injections of MDL- 28170 40 min before and up to day three after CCI; c) sustained application via intraperitoneal osmotic pumps. The control animals received the vehicle DMSO/PEG 400. The tolerable dose of MDL-28170 for mice was 30 mg/kg body weight, higher doses were lethal within the first hours after application. Mechanical withdrawal thresholds and thermal withdrawal latencies were reduced after CCI and did not normalize after single or serial injections, nor with application of MDL-28170 via osmotic pumps. Although the calpain inhibitor MDL-28170 inhibits the early local cytokine upregulation in the sciatic nerve after CCI, pain behavior is not altered. This finding implies that local cytokine upregulation after nerve injury alone is only one factor in the induction and maintenance of neuropathic pain.
KW  - Medizin
KW  - calpain
KW  - neuropathic pain
KW  - MDL-28170
KW  - chronic constriction nerve injury (CCI)
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68359
ER  - 
TY  - JOUR
A1  - Chen, Yong
A1  - Boettger, Michael K.
A1  - Reif, Andreas
A1  - Schmitt, Angelika
A1  - Ueceyler, Nurcan
A1  - Sommer, Claudia
T1  - Nitric oxide synthase modulates CFA-induced thermal hyperalgesia through cytokine regulation in mice
N2  - 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.
KW  - Medizin
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68349
ER  - 
TY  - JOUR
A1  - Braeuninger, Stefan
A1  - Kleinschnitz, C.
A1  - Stoll, G.
T1  - Interleukin-18 does not influence infarct volume or functional outcome in the early stage after transient focal brain ischemia in mice
N2  - Interleukin-18 (IL-18) is a proinflammatory cytokine of the interleukin-1 family which is upregulated after cerebral ischemia. The functional role of IL-18 in cerebral ischemia is unknown. In the present study, we compared infarct size in IL-18 knock-out and wild-type mice 24 hours and 48 hours after 1-hour transient middle cerebral artery occlusion (tMCAO). Moreover, the functional outcome was evaluated in a modified Bederson score, foot fault test and grip test. There were no significant differences in infarct size or functional outcome tests between wild-type and IL-18 knock-out mice. These data indicate that the early inflammatory response to cerebral ischemia does not involve IL-18, in contrast to other interleukin-1 family members such as interleukin-1.
KW  - Interleukin-18
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68141
ER  - 
TY  - JOUR
A1  - Ehling, P.
A1  - Bittner, S.
A1  - Bobak, N.
A1  - Schwarz, T.
A1  - Wiendl, H.
A1  - Budde, T.
A1  - Kleinschnitz, Christoph
A1  - Meuth, S. G.
T1  - Two pore domain potassium channels in cerebral ischemia: a focus on K2p9.1 (TASK3, KCNK9)
N2  - BACKGROUND: Recently, members of the two-pore domain potassium channel family (K2P channels) could be shown to be involved in mechanisms contributing to neuronal damage after cerebral ischemia. K2P3.1-/- animals showed larger infarct volumes and a worse functional outcome following experimentally induced ischemic stroke. Here, we question the role of the closely related K2P channel K2P9.1. METHODS: We combine electrophysiological recordings in brain-slice preparations of wildtype and K2P9.1-/- mice with an in vivo model of cerebral ischemia (transient middle cerebral artery occlusion (tMCAO)) to depict a functional impact of K2P9.1 in stroke formation. RESULTS: Patch-clamp recordings reveal that currents mediated through K2P9.1 can be obtained in slice preparations of the dorsal lateral geniculate nucleus (dLGN) as a model of central nervous relay neurons. Current characteristics are indicative of K2P9.1 as they display an increase upon removal of extracellular divalent cations, an outward rectification and a reversal potential close to the potassium equilibrium potential. Lowering extracellular pH values from 7.35 to 6.0 showed comparable current reductions in neurons from wildtype and K2P9.1-/- mice (68.31 +/- 9.80% and 69.92 +/- 11.65%, respectively). These results could be translated in an in vivo model of cerebral ischemia where infarct volumes and functional outcomes showed a none significant tendency towards smaller infarct volumes in K2P9.1-/- animals compared to wildtype mice 24 hours after 60 min of tMCAO induction (60.50 +/- 17.31 mm3 and 47.10 +/- 19.26 mm3, respectively). CONCLUSIONS: Together with findings from earlier studies on K2P2.1-/- and K2P3.1-/- mice, the results of the present study on K2P9.1-/- mice indicate a differential contribution of K2P channel subtypes to the diverse and complex in vivo effects in rodent models of cerebral ischemia.
KW  - Kaliumkanal
KW  - Ischemia
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68129
ER  - 
TY  - JOUR
A1  - Pham, Mirko
A1  - Helluy, X.
A1  - Braeuninger, S.
A1  - Jakob, P.
A1  - Stoll, G.
A1  - Kleinschnitz, Christoph
A1  - Bendszus, M.
T1  - Outcome of experimental stroke in C57Bl/6 and Sv/129 mice assessed by multimodal ultra-high field MRI
N2  - Transgenic mice bred on C57Bl/6 or Sv/129 genetic background are frequently used in stroke research. It is well established that variations in cerebrovascular anatomy and hemodynamics can influence stroke outcome in different inbred mouse lines. We compared stroke development in C57Bl/6 and Sv/129 mice in the widely used model of transient middle cerebral artery occlusion (tMCAO) by multimodal ultra-high field magnetic resonance imaging (MRI). C57Bl/6 and Sv/129 mice underwent 60 min of tMCAO and were analyzed by MRI 2 h and 24 h afterwards. Structural and functional images were registered to a standard anatomical template. Probability maps of infarction were rendered by automated segmentation from quantitative T2-relaxometric images. Whole-brain segmentation of infarction was accomplished manually on high-resolution T2-weighted (T2-w) RARE images. Cerebral perfusion (cerebral blood flow, CBF) was measured quantitatively by modified continuous arterial-spin-labeling (CASL) and apparent diffusion coefficients (ADC) by spin-echo diffusion-weighted imaging (DWI). Probabilities of cortical (95.1% ± 3.1 vs. 92.1% ± 2.5; p > 0.05) and subcortical (100% vs. 100%; p > 0.05) infarctions at 24 h were similar in both groups as was the whole-brain volumetric extent of cerebral infarction. In addition, CBF and ADC values did not differ between C57Bl/6 and Sv/129 mice at any time point or region of interest. The C57Bl/6 and Sv/129 genetic background is no major confounding factor of infarct size and cerebral perfusion in the tMCAO model.
KW  - NMR-Tomographie
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68115
ER  - 
TY  - JOUR
A1  - Kraft, P.
A1  - Schwarz, T.
A1  - Pochet, L.
A1  - Stoll, G.
A1  - Kleinschnitz, Christoph
T1  - COU254, a specific 3-carboxamide-coumarin inhibitor of coagulation factor XII, does not protect mice from acute ischemic stroke
N2  - Background: Anticoagulation is an important means to prevent from acute ischemic stroke but is associated with a significant risk of severe hemorrhages. Previous studies have shown that blood coagulation factor XII (FXII)- deficient mice are protected from pathological thrombus formation during cerebral ischemia without bearing an increased bleeding tendency. Hence, pharmacological blockade of FXII might be a promising and safe approach to prevent acute ischemic stroke and possibly other thromboembolic disorders but pharmacological inhibitors selective over FXII are still lacking. In the present study we investigated the efficacy of COU254, a novel nonpeptidic 3-carboxamide-coumarin that selectively blocks FXII activity, on stroke development and post stroke functional outcome in mice. Methods: C57Bl/6 mice were treated with COU254 (40 mg/kg i.p.) or vehicle and subjected to 60 min transient middle cerebral artery occlusion (tMCAO) using the intraluminal filament method. After 24 h infarct volumes were determined from 2,3,5-Triphenyltetrazoliumchloride(TTC)-stained brain sections and functional scores were assessed. Hematoxylin and eosin (H&E) staining was used to estimate the extent of neuronal cell damage. Thrombus formation within the infarcted brain areas was analyzed by immunoblot. Results: Infarct volumes and functional outcomes on day 1 after tMCAO did not significantly differ between COU254 pre-treated mice or untreated controls (p > 0.05). Histology revealed extensive ischemic neuronal damage regularly including the cortex and the basal ganglia in both groups. COU254 treatment did not prevent intracerebral fibrin(ogen) formation. Conclusions: COU254 at the given concentration of 40 mg/kg failed to demonstrate efficacy in acute ischemic stroke in this preliminary study. Further preclinical evaluation of 3-carboxamide-coumarins is needed before the antithrombotic potential of this novel class of FXII inhibitors can be finally judged.
KW  - Schlaganfall
KW  - Maus
KW  - COU254
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68103
ER  - 
TY  - RPRT
A1  - Magnus, Tim
A1  - Linker, Ralf A.
A1  - Meuth, Sven G.
A1  - Kleinschnitz, Christoph
A1  - Korn, Thomas
T1  - Report on the 2nd scientific meeting of the "Verein zur Foerderung des Wissenschaftlichen Nachwuchses in der Neurologie" (NEUROWIND e.V.) held in Motzen, Germany, Oct. 29'th - Oct. 31'st, 2010
N2  - Summary of the scientific contributions to the NEUROWIND meeting 2010: Contributions in the fields of neuroimmunology and neurodegeneration
KW  - Wissenschaftlicher Nachwuchs
KW  - Neurologie
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68789
ER  - 
TY  - THES
A1  - Topuzoglu, Tengü Gülsüm
T1  - Charakterisierung von IL-4 Knockout-Mäusen und ihrer Zytokin- und Opioidrezeptor-Expression im peripheren und zentralen Nervensystem
T1  - Characterization of IL-4 knockout-mice and their cytokine- and opioidreceptor gene expression in the peripheral and central nervous system
N2  - In der vorliegenden Arbeit wurde der Einfluss eines Mangels des antiinflammatorischen Zytokins Interleukin(IL)-4 am Tiermodell einer experimentellen Mononeuropathie (engl. chronic constriction injury, CCI) untersucht. Zentrale Fragestellung der Studie war, ob IL-4 knockout(ko)-Mäuse im Vergleich zu Wildtyp(wt)-Mäusen mit einem gesteigerten Schmerzverhalten sowie einer veränderten Zytokinantwort und Opioidrezeptor-Expression nach Anwendung eines neuropathischen Schmerzmodells (CCI) reagieren. In mehreren Tierstudien war zuvor eine antiinflammatorische und analgetische Wirkung von IL-4 belegt worden (Vale et al. 2003; Hao et al. 2006) und in klinischen Studien war ein verminderter IL-4-Spiegel bei Patienten mit verschiedenen neuropathischen Schmerzsyndromen mit einer gesteigerten Schmerzempfindung verbunden (Üçeyler et al. 2006; Üçeyler et al. 2007b). Da IL-4 die Transkription von Opioidrezeptoren induziert (Kraus et al. 2001; Börner et al. 2004), wurde zudem das Ansprechen von IL-4 ko-Mäusen auf Morphin und die Genexpression zentraler Opioidrezeptoren untersucht. Vor sowie bis vier Wochen nach Durchführung einer CCI wurden IL-4 ko- sowie wt- Mäuse hinsichtlich ihrer Empfindlichkeit auf mechanische und thermische Stimuli analysiert. Zum Zeitpunkt des Schmerzmaximums nach CCI (Tag 7 bis 9) wurde zudem das Ansprechen beider Genotypen auf Morphin untersucht. Die Genexpression pro- (IL-1 beta, TNF) und antiinflammatorischer Zytokine (IL-10, IL- 13) im peripheren (N. ischiadicus) und zentralen Nervensystem (lumbales und zervikales Rückenmark, Pons, Thalamus, Hypothalamus, Striatum, Kortex) sowie die Genexpression zentraler Opioidrezeptoren (mü-OR, delta-OR, kappa-OR) wurde bei beiden Genotypen vor sowie vier Wochen nach CCI mittels Real-Time-PCR bestimmt. Unbehandelte IL-4 ko-Mäuse zeigten im Vergleich zu wt-Mäusen bereits vor Durchführung einer CCI eine mechanische Überempfindlichkeit (Hyperalgesie), was möglicherweise durch die bei IL-4-Mangel fehlenden zentralen inhibitorischen Mechanismen bedingt ist. Nach CCI entwickelten sowohl IL-4 ko- als auch wt-Mäuse eine gleich ausgeprägte mechanische und thermische Hyperalgesie. Die Tatsache, dass die mechanische Überempfindlichkeit bei IL-4 ko-Mäusen nach Nervenläsion nicht überproportional steigt, kann Ausdruck der nachgewiesenen kompensatorisch stärker ausgeprägten Genexpression proinflammatorischer, aber insbesondere auch antiinflammatorischer Zytokine in diesem Genotyp sein. Nur bei IL-4 ko-Mäusen war vier Wochen nach CCI die Genexpression der anti- inflammatorischen Zytokine im N. ischiadicus (IL-10) und ipsilateralen Rückenmark (IL-10, IL-13), jedoch auch die der proinflammatorischen Zytokine im ipsilateralen Rückenmark (TNF, IL-1 beta) erhöht. Nach CCI sprachen IL-4 ko-Mäuse schneller auf Morphingabe an als wt-Mäuse, was durch den bei diesem Genotyp stärker ausgeprägten Anstieg der Genexpression der Opioidrezeptortypen delta-OR und kappa-OR im kontralateralen Thalamus bedingt sein kann.
N2  - In this study the pain behavior of IL-4 knockout (ko) mice was characterized before and after chronic constriction injury (CCI) of the sciatic nerve as an established model for neuropathic pain. The opioid responsivity of IL-4 ko-mice was tested and four weeks after CCI the cytokine and opioid receptor gene expression in the peripheral and central nervous system of IL-4 ko mice was measured compared to wildtype (wt) mice. Before CCI IL-4 ko mice showed tactile allodynia, while responses to heat did not differ in comparison to wt-mice. No compensatory changes in the gene expression of the measured cytokines (tumor necrosis factor-alpha (TNF), IL-1b, IL-10, and IL-13) were found in the PNS and CNS of na ̈ıve IL-4 ko mice. Four weeks after CCI IL-1b gene expression was stronger in the sciatic nerve of IL-4 ko mice (p,0.001) and only IL-4 ko mice had elevated IL-10 gene expression in the sciatic nerve. Only in IL-4 ko-mice there was an upregulated gene expression four weeks after CCI of TNF (p,0.01), IL-1b (p,0.05), IL-10 (p,0.05), and IL-13 (p,0.001) in the ipsilateral spinal cord. The compensatory overexpression of the anti-inflammatory cytokines IL-10 and IL-13 in the spinal cord of IL-4 ko mice may explain the lack of genotype differences for pain behavior after CCI. CCI upregulated gene expression of k, and d opioid receptors in the contralateral thalamus of IL-4 ko mice, in accordance with an observed fast onset of morphine analgesia compared to wt mice.
KW  - Neuralgie
KW  - Interleukin-4
KW  - Zytokin
KW  - Opioidrezeptor
KW  - Genexpression
KW  - Neuropathischer Schmerz
KW  - Interleukin-4
KW  - cytokine
KW  - opioidreceptor
KW  - mRNA expression
KW  - mice
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72372
ER  -