Effects of interactions between amphetamine and food deprivation on covariation of muricide, consummatory behaviour and activity.

Four experiments were conducted to study covariation of muricide, consummatory behaviour and general activity under conditions involving interactions between food deprivation and anorexia induced by low doses of d-amphetamine. Two basic experimental designs were used: (a) dosage of amphetamine was varied, with duration of deprivation constant at 22 hr; and (b) deprivation was varied, with a constant amphetamine dose of 1.0 mg/kg body weight. In general, effects of both types of manipulation on eating, drinking, general activity, and muricidal behaviour were consistent with earlier reports of effects when either deprivation or amphetamine-induced anorexia was varied separately. Rank order correlations supported the conclusions that relations between muricide, eating behaviour and general activity were both dose and time dependent. However, there also was evidence that such covariations existed for some, but not all, parameters of these behaviours, eg. differences in the median effective doses of amphetamine; differences in threshold doses; and differences in durations of deprivation required to counteract effects of amphetamine. A dissociation of muricide and eating behaviour was strikingly evident when all satiated animals injected with normal saline engaged in muricidal behaviour and when increasing deprivation had no significant influence on carcass consumption or muricidal behaviour of saline treated subjects. The present results are interpreted as essentially inconsistent with concepts in which covariation of muricide and consummatory behaviour is considered to depend: (a) upon a common set of physiological conditions, or (b) upon one being the antecedent of the other. However, results are consistent with a model in which each behaviour has its own basic physiological condition(s) which may be activated concomitantly.