N. Wongwitdecha et Ca. Marsden, ISOLATION REARING PREVENTS THE REINFORCING PROPERTIES OF AMPHETAMINE IN A CONDITIONED PLACE PREFERENCE PARADIGM, European journal of pharmacology, 279(1), 1995, pp. 99-103
Social isolation has been demonstrated to alter individual reactivity
to addictive drugs. The present experiments compared the effects of is
olation rearing and socially rearing rats on the reinforcing propertie
s of amphetamine. Male Lister hooded rats were housed from 21 days (we
aning) either alone (isolation reared rats) or in groups of four rats
per cage (socially reared rats). Six weeks later, the rats were tested
for their sensitivity to d-amphetamine (1.5 and 5 mg/kg) using a cond
itioned place preference paradigm. The treatment quadrant was selected
as that in which the rat spent least time during a preconditioning tr
ial. After saline conditioning, the socially reared rats showed a sign
ificant (P < 0.05) aversion for the treatment quadrant relative to the
opposite quadrant. Following amphetamine (1.5; 5 mg/kg) conditioning,
socially reared rats spent significantly more time (P < 0.05) in the
treatment quadrant relative to the opposite quadrant while isolation r
eared rats failed to display either the aversion effect of saline cond
itioning or amphetamine induced place preference. These results demons
trate isolation rearing prevents the reinforcing properties of ampheta
mine.