Anxiolytic actions of the substance P (NK1) receptor antagonist L-760735 and the 5-HT1A agonist 8-OH-DPAT in the social interaction test in gerbils

The gerbil social interaction test has previously detected anxiolytic effec ts of nicotine and diazepam. In the present study, the high affinity substa nce P (NK1) receptor antagonist L-760735 (3 mg/kg) significantly increased the time spent in social interaction, whereas its low affinity analogue L-7 81773 (3 mg/kg) was without effect. Diazepam (0.1 mg/kg) and the 5-HT1A rec eptor agonist 8-OH-DPAT (0.003 and 0.01 mg/kg) also increased social intera ction, whereas an acute dose of the selective serotonin re-uptake inhibitor fluoxetine (10 mg/kg) decreased the time spent in social interaction. Diaz epam (0.1 mg/kg) significantly increased locomotor activity, but this effec t was independent of the increase in social interaction. The other drugs te sted were without effect on locomotor activity. The present findings sugges t that the gerbil social interaction may well provide a useful assay for de tecting both anxiolytic and anxiogenic compounds, and suggests that the hig h affinity NK1 receptor antagonist L-760735 may prove to be useful as an an xiolytic therapy. (C) 2001 Elsevier Science BY. All rights reserved.