Effects of nicotinic and muscarinic compounds on biting attack in the cat.

Predatory-like biting attack on a rat, as well as hissing, growling, and other threat behaviors, could be induced in normally non-aggressive cats by systemic administration of the muscarinic agonist, arecoline (7-12 mg/kg). In contrast to arecoline, nicotine was found to suppress aggressive behaviors. Systemic administration of nicotine (0.5 mg/kg) prior to arecoline injection resulted in a significant reduction in elicited attack and threat behaviors. Furthermore, nicotine (0.075-0.500 mg/kg) was found to produce a dose-dependent suppression of natural predatory behavior as well. This nicotine-produced suppression of attack did not appear to be due to the induction of general malaise, since attack suppression could be seen in the absence of general behavioral inhibition, and doses of nicotine resulting in complete suppression of attack had little effect on food intake. Results indicate that muscarinic and nicotinic compounds can exert antagonistic control over some types of aggressive behaviors.