title: Region-specific expression of brain-derived neurotrophic factor splice variants in morphine conditioned place preference in mice.
abstract: It is well established that brain-derived neurotrophic factor (BDNF) plays a pivotal role in brain plasticity-related processes, such as learning, memory and drug addiction. However, changes in expression of BDNF splice variants after acquisition, extinction and reinstatement of cue-elicited morphine seeking behavior have not yet been investigated. Real-time PCR was used to assess BDNF splice variants (I, II, IV and VI) in various brain regions during acquisition, extinction and reinstatement of morphine-conditioned place preference (CPP) in mice. Repeated morphine injections (10mg/kg, i.p.) increased expression of BDNF splice variants II, IV and VI in the hippocampus, caudate putamen (CPu) and nucleus accumbens (NAcc). Levels of BDNF splice variants decreased after extinction training and continued to decrease during reinstatement induced by a morphine priming injection (10mg/kg, i.p.). However, after reinstatement induced by exposure to 6 min of forced swimming (FS), expression of BDNF splice variants II, IV and VI was increased in the hippocampus, CPu, NAcc and prefrontal cortex (PFC). After reinstatement induced by 40 min of restraint, expression of BDNF splice variants was increased in PFC. These results show that exposure to either morphine or acute stress can induce reinstatement of drug-seeking, but expression of BDNF splice variants is differentially affected by chronic morphine and acute stress. Furthermore, BDNF splice variants II, IV and VI may play a role in learning and memory for morphine addiction in the hippocampus, CPu and NAcc.
authors.affiliation: Department of Oncology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, 277# West YantaRoad, Xi'an 710061, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Meng
authors.forename: Xinhan
authors.initials: X
authors.lastname: Zhao
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Dang
authors.forename: Jingyuan
authors.initials: J
authors.lastname: Ma
authors.forename: Lixu
authors.initials: L
authors.lastname: Li
authors.forename: Shanzhi
authors.initials: S
authors.lastname: Gu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D003216:Conditioning, Operant / Q000187:drug effects*; D058999:Drug-Seeking Behavior / Q000187:drug effects / Q000502:physiology; D005108:Extinction, Psychological / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009020:Morphine / Q000378:metabolism / Q000494:pharmacology*; D009294:Narcotics / Q000378:metabolism / Q000494:pharmacology*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012054:Reinforcement, Psychology
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D009294:Narcotics; D020033:Protein Isoforms; D012333:RNA, Messenger; D009020:Morphine