Behavioral analysis of the effects of benzodiazepine receptor ligands in the conditioned burying paradigm.

In the conditioned burying paradigm, 10 mutually exclusive behavioral sequences were encoded in order to characterize the effects of various benzodiazepine receptor ligands. It was found that each ligand produced a specific behavioral pattern, the elements of which were consistent with results obtained in other experimental situations. Whereas anxiolytic (diazepam, Ro 16-6028) and 'anxiogenic' ligands (FG 7142) both decreased the mean duration of burying, these two classes of drugs largely differed when approaches to the prod and escape movements away from the prod were considered. The benzodiazepine receptor antagonist Ro 15-1788 was devoid of effects on all of the behavioral sequences considered. The main characteristics of these behavioral profiles persisted during an extinction test, although the animals were no longer treated. It is proposed that additional behavioral measures, or better, an ethological analysis of the behavior may increase the potency of the conditioned defensive burying paradigm.