Behavioral effects of acute hexamethonium in rats chronically intoxicated with nicotine

To investigate the effects of chronic nicotine administration on feeding behavior, hexamethonium, a nicotinic blocker with mainly peripheral actions, was acutely given to rats during and after chronic nicotine administration. Nicotine decreased both the time spent investigating the food and the amount of food consumed. It also decreased the time spent rearing and grooming and increased the time spent resting. These behaviors returned to control levels after nicotine withdrawal. During nicotine administration, 10 mg/kg of hexamethonium increased the amount of time the nicotine-treated rats spent investigating the food but did not change the amount of food actually eaten. These data show that predominantly peripheral nicotinic blockade can partially alleviate the effects of chronic nicotine administration of feeding behavior, suggesting that at least some of the effects of nicotine on feeding are peripheral. The finding that the investigational and consummatory aspects of feeding behavior can be pharmacologically differentiated implies that some aspects of their neural control may be distinct.