A PRIMATE MODEL OF ANXIETY

Pentylenetetrazol (PTZ; 30 mg/kg, im) produced an acute anxiogenic eff ect on the behaviour of a social colony of rhesus monkeys acclimatized to laboratory conditions. The animals exhibited hypervigilance, aggre ssiveness, tachypnea, piloerection and frequent change of posture and also had raised plasma cortisol levels. These effects of PTZ were anta gonized by benzodiazepines (diazepam; 1 mg/kg, iv and alprazolam; 0.05 mg/kg, po). Non-benzodiazepine anxiolytic drug (buspirone; 10 mg/kg, po) blocked the behavioural effects but not the rise in plasma cortiso l concentration. On the other hand, pretreatment with hypnosedative (p romethazine; 5 mg/kg, im) or anticonvulsant (sodium valproate; 40 mg/k g, po) agents did not attenuate the effects of PTZ indicating the spec ificity of its anxiogenic response. The model, thus, seems suitable fo r evaluation of potential anxiolytic agents. (C) 1998 Elsevier Science B.V./ECNP.