BEHAVIORAL-EFFECTS IN MICE OF SUBCHRONIC BUSPIRONE, ONDANSETRON AND TIANEPTINE .1. SOCIAL INTERACTIONS

In a continuation of recent work on effects of a benzodiazepine (chlor diazepoxide) and selective monoamine reuptake inhibitors (maprotiline and fluvoxamine), the current study compares effects of the 5-HT1A rec eptor partial agonist, buspirone (0.75-3.0 mg/kg), the 5-HT3 receptor antagonist, ondansetron (0.1-100 mu g/kg) and the novel antidepressant , tianeptine (2.5-10.0 mg/kg). Compounds were given daily to mice for 21 days prior to testing and the subsequent behaviour of the animals d uring social interactions was assessed by ethopharmacological procedur es. Buspirone, at 0.75 mg/kg, increased immobility and reduced occurre nce of the aggressive act, ''attack.'' At 1.5 and 3.0 mg/kg, it enhanc ed olfactory exploration of the sawdust substrate, but had no effect o n social investigation. Ondansetron increased the duration of environm ental exploration at 0.1 mu g/kg, while at 100 mu g/kg it increased th e duration of digging in the substrate. Ondansetron had no effect on t he categories of behaviour and failed to induce an anxiolytic-like enh ancement of social investigation. Tianeptine produced an anxiogenic-li ke effect at 10 mg/kg, while at 5 mg/kg it enhanced flight and immobil ity. The relevance of these findings is discussed in relation of the r eported behavioural actions of these compounds and to current pharmaco therapy of anxiety and depression. The apparent anxiogenic effect of t ianeptine is a novel finding which requires further study. Copyright ( C) 1997 Elsevier Science Inc.