Effects of naloxone and neurotensin on excessive grooming behavior of rats induced by bombesin, beta-endorphin and ACTH.

Bombesin, beta-endorphin and ACTH-(1-24) induce excessive grooming behavior in rats. Whereas ACTH increases the frequency of all components of grooming behavior (head washing, bodily grooming and paw licking), the most pronounced element of bombesin- and beta-endorphin-induced excessive grooming is scratching. Naloxone counteracts peptide-induced grooming and in particular excessive scratching is reduced by this opiate antagonist. Also neurotensin suppresses peptide-induced grooming behavior and in particular scratching. It is concluded that the element scratching is the component of grooming behavior which is mainly displayed by activation of opiate receptors and that neurotensin is able to interfere with opiate receptor mediated behavior.