The effects of chronic chlordiazepoxide administration on ingestion of edible and nonedible substances by rats.

Chronic administration of chlordiazepoxide (CDP) is known to increase feeding in several species and under different procedures. Although this effect does not appear to result from antineophobic and anxiolytic effects of this benzodiazepine, very little is known about the possible contribution of stereotyped nibbling and chewing responses to enhanced feeding. The present study addressed this issue. Experiments 1 and 2 showed that rats injected with 5 and 10 mg/kg CDP spent more time chewing wood than either food-deprived or satiated rats. Experiment 3 showed that rats chronically injected with CDP spent more time chewing biscuits than wood in choice tests; with repeated choice testing chewing biscuits increased while chewing wood decreased. Experiment 4 replicated these results, and ruled out the possibility that increased time chewing resulted only from the self-rewarding effects of chewing. Finally, Experiments 3 and 4 also showed that despite these strong local effects on feeding time, body weight and the amount of food and water ingested every day for 10 days were not increased by 5 and 10 mg/kg CDP. It is unlikely that the effects of CDP on feeding results only from induction of stereotyped nibbling and chewing.