title: Morphine treatment enhances glutamatergic input onto neurons of the nucleus accumbens via both disinhibitory and stimulating effect.
abstract: Drug addiction is a chronic brain disorder characterized by the compulsive repeated use of drugs. The reinforcing effect of repeated use of drugs on reward plays an important role in morphine-induced addictive behaviors. The nucleus accumbens (NAc) is an important site where morphine treatment produces its reinforcing effect on reward. However, how morphine treatment produces its reinforcing effect on reward in the NAc remains to be clarified. In the present study, we studied the influence of morphine treatment on the effects of DA and observed whether morphine treatment could directly change glutamatergic synaptic transmission in the NAc. We also explored the functional significance of morphine-induced potentiation of glutamatergic synaptic transmission in the NAc at behavioral level. Our results show that (1) morphine treatment removes the inhibitory effect of DA on glutamatergic input onto NAc neurons; (2) morphine treatment potentiates glutamatergic input onto NAc neurons, especially the one from the basolateral amygdala (BLA) to the NAc; (3) blockade of glutamatergic synaptic transmission in the NAc or ablation of projection neurons from BLA to NAc significantly decreases morphine treatment-induced increase in locomotor activity. These results suggest that morphine treatment enhances glutamatergic input onto neurons of the NAc via both disinhibitory and stimulating effect and therefore increases locomotor activity.
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Kejing
authors.initials: K
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Sheng
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Song
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Dongyang
authors.initials: D
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Lai
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, Fudan University, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zheng
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004195:Disease Models, Animal; D018698:Glutamic Acid / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D009293:Opioid-Related Disorders / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D000701:Analgesics, Opioid; D018698:Glutamic Acid; D009020:Morphine
keywords: basolateral amygdala; dopamine; glutamate release; locomotor; morphine; nucleus accumbens