title: BDNF parabrachio-amygdaloid pathway in morphine-induced analgesia.
abstract: In addition to its neurotrophic role, brain-derived neurotrophic factor (BDNF) is involved in a wide array of functions, including anxiety and pain. The central amygdaloid nucleus (CeA) contains a high concentration of BDNF in terminals, originating from the pontine parabrachial nucleus. Since the spino-parabrachio-amygdaloid neural pathway is known to convey nociceptive information, we hypothesized a possible involvement of BDNF in supraspinal pain-related processes. To test this hypothesis, we generated localized deletion of BDNF in the parabrachial nucleus using local bilateral injections of adeno-associated viruses in adult floxed-BDNF mice. Basal thresholds of thermal and mechanical nociceptive responses were not altered by BDNF loss and no behavioural deficit was noticed in anxiety and motor tests. However, BDNF-deleted animals displayed a major decrease in the analgesic effect of morphine. In addition, intra-CeA injections of the BDNF scavenger TrkB-Fc in control mice also decreased morphine-induced analgesia. Finally, the number of c-Fos immunoreactive nuclei after acute morphine injection was decreased by 45% in the extended amygdala of BDNF-deleted animals. The absence of BDNF in the parabrachial nucleus thus altered the parabrachio-amygdaloid pathway. Overall, our study provides evidence that BDNF produced in the parabrachial nucleus modulates the functions of the parabrachio-amygdaloid pathway in opiate analgesia.
authors: Université de Strasbourg, Strasbourg, France.
authors: Maysa
authors: M
authors: Sarhan
authors: Sophie Anne
authors: SA
authors: Pawlowski
authors: Florent
authors: F
authors: Barthas
authors: Ipek
authors: I
authors: Yalcin
authors: Jennifer
authors: J
authors: Kaufling
authors: Hugues
authors: H
authors: Dardente
authors: Venetia
authors: V
authors: Zachariou
authors: Ralph Joseph
authors: RJ
authors: Dileone
authors: Michel
authors: M
authors: Barrot
authors: Pierre
authors: P
authors: Veinante
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000378:metabolism*; D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D003623:Dark Adaptation / Q000187:drug effects; D000229:Dependovirus / Q000235:genetics; D005106:Exploratory Behavior / Q000187:drug effects; D006930:Hyperalgesia / Q000188:drug therapy; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009020:Morphine / Q000494:pharmacology*; D009434:Neural Pathways / Q000187:drug effects; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D011149:Pons / Q000187:drug effects / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D045442:Rotarod Performance Test
chemical_list: D000701:Analgesics, Opioid; D019208:Brain-Derived Neurotrophic Factor; D016760:Proto-Oncogene Proteins c-fos; D009020:Morphine