title: Cholecystokinin-octapeptide restored morphine-induced hippocampal long-term potentiation impairment in rats.
abstract: Cholecystokinin-octapeptide (CCK-8), which is a typical brain-gut peptide, exerts a wide range of biological activities on the central nervous system. We have previously reported that CCK-8 significantly alleviated morphine-induced amnesia and reversed spine density decreases in the CA1 region of the hippocampus in morphine-treated animals. Here, we investigated the effects of CCK-8 on long-term potentiation (LTP) in the lateral perforant path (LPP)-granule cell synapse of rat dentate gyrus (DG) in acute saline or morphine-treated rats. Population spikes (PS), which were evoked by stimulation of the LPP, were recorded in the DG region. Acute morphine (30mg/kg, s.c.) treatment significantly attenuated hippocampal LTP and CCK-8 (1μg, i.c.v.) restored the amplitude of PS that was attenuated by morphine injection. Furthermore, microinjection of CCK-8 (0.1 and 1μg, i.c.v.) also significantly augmented hippocampal LTP in saline-treated (1ml/kg, s.c.) rats. Pre-treatment of the CCK2 receptor antagonist L-365,260 (10μg, i.c.v) reversed the effects of CCK-8, but the CCK1 receptor antagonist L-364,718 (10μg, i.c.v) did not. The present results demonstrate that CCK-8 attenuates the effect of morphine on hippocampal LTP through CCK2 receptors and suggest an ameliorative function of CCK-8 on morphine-induced memory impairment.
authors.affiliation: Department of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Shijiazhuang 050017, PR China.
authors.forename: Di
authors.initials: D
authors.lastname: Wen
authors.affiliation: Department of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Shijiazhuang 050017, PR China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Zang
authors.affiliation: Department of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Shijiazhuang 050017, PR China.
authors.forename: DongLei
authors.initials: D
authors.lastname: Sun
authors.affiliation: Department of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Shijiazhuang 050017, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yu
authors.affiliation: Department of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Shijiazhuang 050017, PR China.
authors.forename: Dong
authors.initials: D
authors.lastname: Mei
authors.affiliation: Department of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Shijiazhuang 050017, PR China. Electronic address: chunlingma@126.com.
authors.forename: Chunling
authors.initials: C
authors.lastname: Ma
authors.affiliation: Department of Forensic Medicine, Hebei Medical University, Hebei Key Laboratory of Forensic Medicine, Shijiazhuang 050017, PR China. Electronic address: hbydbincong@126.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Cong
mesh_terms: D000818:Animals; D004567:Electrodes, Implanted; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology*; D017774:Long-Term Potentiation / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D008845:Microinjections; D009020:Morphine / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D012844:Sincalide / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D009020:Morphine; D012844:Sincalide
keywords: CCK receptor; Cholecystokinin-octapeptide; Hippocampus; Long-term potentiation; Morphine