Behavioral depression during cocaine withdrawal is associated with decreased spontaneous activity of ventral tegmental area dopamine neurons.
Withdrawal from an escalating-dose, bingelike regimen of cocaine administration in rats produced significantly depressed levels of locomotor activity during the nocturnal portion of the day-night cycle. This effect was observed during the first 48 hr of testing. Extracellular single-unit recordings of ventral tegmental area (VTA) dopamine (DA) neurons revealed no differences between saline- and cocaine-treated rats with respect to basal firing rates. However, significantly fewer spontaneously active VTA DA neurons were encountered in rats withdrawn from binge cocaine. As with the nocturnal hypoactivity, this effect was observed only during the first 48 hr of withdrawal. These findings suggest that short-term DA neuron dysfunction during cocaine withdrawal temporally corresponds to behavioral disruptions that are similar to those described in human addicts.
Koeltzow
Timothy E
TE
Department of Neuroscience, Finch University of Health Sciences/The Chicago Medical School, Illinois 60064-3095, USA.
White
Francis J
FJ
D000818:Animals; D002940:Circadian Rhythm; D003042:Cocaine / Q000009:adverse effects* / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000503:physiopathology; D004195:Disease Models, Animal; D004298:Dopamine / Q000494:pharmacology*; D018765:Dopamine Uptake Inhibitors / Q000009:adverse effects* / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity; D009474:Neurons / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000502:physiology; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*; D017557:Ventral Tegmental Area / Q000502:physiology*
D018765:Dopamine Uptake Inhibitors; D011954:Receptors, Dopamine; D003042:Cocaine; D004298:Dopamine