Modern Psychological Studies
University of Tennessee at Chattanooga
Place of Publication
EEDQ is an irreversible receptor antagonist that eliminates the dopamine (DA) mediated behaviors of adults rats. In contrast, EEDQ does not seem to affect the DA mediated behaviors of preweanling rat pups. One explanation for this age dependent difference is that rat pups may have a DA receptor reserve, not available to adults, which is sufficient to mediate behavior. Therefore, the purpose of the present study was to determine whether a Di and D2 receptor reserve exists in preweanling rats. A total of 96, 17-dayold rat pups were injected with EEDQ (7.5 mg/kg) or its vehicle immediately after being trained to approach an anesthetized dam on a straight alley for nipple attachment reward. After 18 hours rat pups were then injected with saline, the D1 agonist SCH 23390 (0.5 mg1kg), or the D2 agonist sulpiride (50 mg/kg). A final testing session occurred 30 min later. This session consisted of an additional 28 trials on the straight alley, in which responding resulted in either reinforcement or extinction. Results of this experiment indicated that EEDQ and SCH 23390 combined to maximally disrupt the extinction responding of the rat pups. Unexpectedly, EEDQ did not potentiate sulpiride's effects. In general, these results indicate that preweanling rat pups do not have a DI or D2 receptor reserve, but age-dependent differences in DA receptor functioning were apparent.
BF1 .M63 v. 2 no. 2 1994
Reid, Suzanne L. and MacDougall, Sanders A.
"Behavioral effects of irreversible dopamine receptor inactivation in the preweanling rat: assessment of the receptor reserve hypothesis,"
Modern Psychological Studies: Vol. 2
, Article 2.
Available at: http://scholar.utc.edu/mps/vol2/iss2/2