title: Morphine induces conditioned place preference behavior in histidine decarboxylase knockout mice.
abstract: Pharmacological and lesion studies have shown that histamine exerts inhibitory effects on morphine-induced reward-seeking behavior. The present study was designed to further investigate the involvement of endogenous histamine in morphine-induced reward-seeking behavior using histidine decarboxylase gene knockout (HDC-KO) mice. Conditioned place preference (CPP) was present in both wild-type (WT) and HDC-KO mice treated with 5 or 10 mg/kg morphine. HDC-KO mice showed stronger morphine-induced CPP as compared with WT mice. Meanwhile, morphine significantly increased dopamine level in the VTA and NAc, especially in HDC-KO mice. However, the extinction of CPP is similar between WT and HDC-KO mice. Moreover, naloxone-precipitated withdrawal jumping was markedly decreased in HDC-KO mice. These results indicate that endogenous histamine inhibits the development, but not the extinction, of morphine-induced CPP and reduces morphine withdrawal sign, probably through modulating dopaminergic activity in the brain.
authors.affiliation: Department of Pharmacology, Yunyang Medical College, Shiyan, China.
authors.forename: Ying-xia
authors.initials: YX
authors.lastname: Gong
authors.forename: Wei-ping
authors.initials: WP
authors.lastname: Zhang
authors.forename: Wen-ting
authors.initials: WT
authors.lastname: Shou
authors.forename: Kai
authors.initials: K
authors.lastname: Zhong
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000701:Analgesics, Opioid / Q000009:adverse effects*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D003214:Conditioning, Classical / Q000187:drug effects*; D005108:Extinction, Psychological; D006632:Histamine / Q000378:metabolism; D006640:Histidine Decarboxylase / Q000235:genetics*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009020:Morphine / Q000009:adverse effects*; D012201:Reward; D013375:Substance Withdrawal Syndrome / Q000378:metabolism / Q000523:psychology
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine; D006632:Histamine; D006640:Histidine Decarboxylase