Effects of desipramine and MK-801 on components of muricidal behaviour in olfactory bulbectomized rats

Both desipramine and MK-801 are reported to suppress the muricidal behaviour and more behavioural components of muricide can be measured for analyses in rats after incisor cutting (IC). In the present work, this IC model was used to assess the differential effects of desipramine and MK-801 on muricidal performance in rats. After IC surgery the olfactory bulbectomized rats were divided into five groups that were then treated with saline (1 ml/kg, i.p.), desipramine (10 or 20 mg/kg, i.p.), or MK-801 (0.10 or 0.15 mg/kg, i.p.). Following drug administration, muricidal behaviour was found to be unchanged in the low-dose desipramine or MK-801 groups compared with the saline controls. Treatment with 20 mg/kg of desipramine increased the attack latency, but reduced the total and mean attack duration as well as attack frequency, while treatment with 0.15 mg/kg of MK-801 resulted in no significant change in the attack latency or total attack duration, but decreased the mean attack duration and increased the attack frequency. These results indicate that the higher dose of both drugs affected the components of the muricidal behaviour in different manners.