title: Reciprocal Inhibitory Interactions Between the Reward-Related Effects of Leptin and Cocaine.
abstract: Cocaine is habit-forming because of its ability to enhance dopaminergic neurotransmission in the forebrain. In addition to neuronal inputs, forebrain dopamine circuits are modulated by hormonal influences; one of these is leptin, an adipose-derived hormone that attenuates the rewarding effects of food- and hunger-associated brain stimulation reward. Here we report reciprocal inhibition between the reward-related effects of leptin and the reward-related effects of cocaine in rats. First, we report that cocaine and the expectancy of cocaine each depresses plasma leptin levels. Second, we report that exogenous leptin, given systemically or directly into the ventral tegmental area, attenuates the ability of cocaine to elevate dopamine levels in the nucleus accumbens, the ability of cocaine to establish a conditioned place preference, and the ability of cocaine-predictive stimuli to prolong responding in extinction of cocaine-seeking. Thus, whereas leptin represents an endogenous antagonist of the habit-forming and habit-sustaining effects of cocaine, this antagonism is attenuated by cocaine and comes to be attenuated by the expectancy of cocaine.
authors.affiliation: Department of Health and Human Services, Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA.
authors.forename: Zhi-Bing
authors.initials: ZB
authors.lastname: You
authors.affiliation: Department of Health and Human Services, Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Health and Human Services, Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA.
authors.forename: Qing-Rong
authors.initials: QR
authors.lastname: Liu
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Biology, Temple University, Philadelphia, PA, USA.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Otvos
authors.affiliation: Department of Health and Human Services, Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA.
authors.forename: Roy A
authors.initials: RA
authors.lastname: Wise
mesh_terms: D000818:Animals; D003042:Cocaine / Q000008:administration & dosage*; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology; D004298:Dopamine / Q000378:metabolism; D058999:Drug-Seeking Behavior / Q000187:drug effects / Q000502:physiology*; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology; D020738:Leptin / Q000008:administration & dosage / Q000378:metabolism / Q000502:physiology*; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D012201:Reward; D015398:Signal Transduction / Q000187:drug effects; D017557:Ventral Tegmental Area / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*
chemical_list: D020738:Leptin; D003042:Cocaine; D004298:Dopamine