Canalization of arousal in the preweanling rat: effects of amphetamine on aggregation with surrogate stimuli.
Preweanling rats, 15 days of age, were placed in an unfamiliar cage containing 1 of a variety of surrogate conspecific stimuli. The surrogate stimuli consisted of a rat-sized aluminum tube covered with soft fluffy synthetic fur, a tanned rat pelt, felt, and an aluminum sheet. The surrogate was either maintained at ambient temperature or heated to body surface temperature (37 degrees C). The 1st experiment revealed that both furriness (length and softness of fur) and temperature of the surrogate stimulus are important determinants of conspecific aggregation (huddling). The 2nd experiment demonstrated that preference for the soft, fluffy surrogate was not mediated by temperature conservation by showing that the same huddling behavior was obtained when ambient temperature was raised to thermoneutrality (33 degrees C). The final experiment demonstrated that amphetamine restricted the range of surrogate stimuli that elicited huddling in the preweanling rat. The finding that amphetamine produces a steeper generalization gradient of approach to surrogate stimuli further confirms our previous hypothesis that amphetamine canalizes arousal toward salient environmental stimuli. These findings have implications for the use of amphetamines to treat hyperkinetic children.
D000818:Animals; D000831:Animals, Newborn; D001143:Arousal / Q000187:drug effects*; D003463:Cues; D003913:Dextroamphetamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D012919:Social Behavior
D003913:Dextroamphetamine