Self-administration of intravenous amphetamine is predicted by individual differences in sucrose feeding in rats.
BACKGROUND
Previous studies have shown that individual differences in oral sucrose consumption are predictive of the psychomotor and dopamine (DA) stimulant properties of amphetamine in rats.


OBJECTIVE
The present experiment was designed to examine the relationship between sucrose feeding and the reinforcing properties of amphetamine using the intravenous (i.v.) drug self-administration paradigm.


METHODS
Based on a median split of sucrose intake during a final 1-h feeding test session, male Wistar rats were designated as either low (LSF) or high sucrose feeders (HSF). Acquisition of i. v.-amphetamine self-administration across ten daily 30-min sessions was then assessed. Following acquisition, i.v. self-administration of several doses of amphetamine was similarly tested across daily 30-min sessions.


RESULTS
Data from this experiment revealed augmented responding in HSF compared with LSF during acquisition of amphetamine self-administration. Correspondingly, when given access to different doses of amphetamine, responding was greater in HSF than in LSF across several doses (3 microg and 10 microg per infusion).


CONCLUSIONS
These data support the notion that individual differences in oral sucrose consumption are predictive of the reinforcing properties of psychostimulant drugs.
DeSousa
N J
NJ
Department of Psychology, University of Toronto, Toronto, Ontario, Canada M5S 363.
Bush
D E
DE
Vaccarino
F J
FJ
D000661:Amphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007262:Infusions, Intravenous; D051379:Mice; D011597:Psychomotor Performance / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012054:Reinforcement, Psychology; D012646:Self Administration; D013395:Sucrose / Q000008:administration & dosage*
D018765:Dopamine Uptake Inhibitors; D013395:Sucrose; D000661:Amphetamine