Behavioural specificity of 8-OH-DPAT-induced feeding.

8-Hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) has been reported to increase food intake. This effect was confirmed in rats consuming plain or sweetened wet mash. However, the consumption of a 35% sucrose solution or of a range of other flavoured liquids was enhanced marginally if at all by a single low dose of 8-OH-DPAT, and the drug actually decreased the consumption of a high protein liquid diet. 8-OH-DPAT did, however, increase gnawing on a wooden block. These results suggest that 8-OH-DPAT-induced "hyperphagia" may to some extent be secondary to the elicitation of chewing behaviour. 8-OH-DPAT also caused certain other behavioural changes, including a suppression of grooming.