Increased successive negative contrast in rats withdrawn from an escalating-dose schedule of D-amphetamine.
The exposure of humans and animals to high doses of psychostimulant drugs, followed by their withdrawal, leads to a number of aversive psychological symptoms. These symptoms include increased anxiety and anhedonia, and may be manifested behaviorally as a decreased interest in normally rewarding stimuli. In the present study, we determine the effects of withdrawal from an escalating-dose schedule of D-amphetamine on the consumption of a 4% sucrose solution under normal conditions, and after an incentive downshift. The downshift was induced by subjecting animals to a consumatory negative contrast paradigm, by switching them from a familiar 32% sucrose solution to a novel 4% solution. In unshifted animals, there was no effect of D-amphetamine withdrawal on consumption of the 4% solution. In contrast, drug-withdrawn animals displayed an exaggerated negative contrast effect, primarily reflected as a delayed recovery from the downshift lasting for at least 60 h. This effect is interpreted as a consequence of the increased emotionality of withdrawn animals, and may be related to disruption of normal search behaviors.
Barr
Alasdair M
AM
Department of Psychology, University of British Columbia, Vancouver, British Columbia, Canada.
Phillips
Anthony G
AG
D000818:Animals; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D003259:Consummatory Behavior / Q000187:drug effects* / Q000502:physiology; D003913:Dextroamphetamine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D008297:Male; D051381:Rats; D020318:Rats, Long-Evans; D013375:Substance Withdrawal Syndrome / Q000523:psychology*; D013395:Sucrose / Q000008:administration & dosage
D000697:Central Nervous System Stimulants; D013395:Sucrose; D003913:Dextroamphetamine