Activity of presumed dopamine neurons in the ventral tegmental area during heroin self-administration.
To assess the pattern of mesocorticolimbic dopamine (DA) activity associated with drug-seeking and drug-taking behavior, we monitored the firing rate of presumed DA neurons in the ventral tegmental area of trained rats during i.v. heroin self-administration (SA). Relative to a slow and irregular basal activity, the first SA of each session was preceded by a phasic increase and followed by a more persistent increase in discharge rate that peaked approximately 15-20 min later at the time of the second SA. All subsequent SAs were associated with a biphasic neuronal change: a transient decrease followed by a gradual increase that peaked just before the next SA. Our results support mesocorticolimbic DA activation in heroin-seeking behavior but suggest a transient inhibition of DA activity correlated with heroin reward.
Kiyatkin
E A
EA
Department of Psychology, Indiana University, Bloomington 47405, USA.
Rebec
G V
GV
D000818:Animals; D004298:Dopamine / Q000502:physiology*; D003932:Heroin / Q000008:administration & dosage* / Q000494:pharmacology; D006556:Heroin Dependence / Q000503:physiopathology* / Q000523:psychology; D008032:Limbic System / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D012646:Self Administration; D013681:Tegmentum Mesencephali / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology*; D013997:Time Factors; D014743:Videotape Recording
D003932:Heroin; D004298:Dopamine