Effects of hashish on isolation induced aggression in wild mice

Abstract

The effects of i.p. administration of a hashish solution on the fighting behaviour of isolated male wild house-mice were examined in a qualitative and quantitative behavioural study. Daily doses of 20 mg/kg led to increased aggressiveness as shown in the different parameters. This was demonstrated in a decrease, significant at the 2% level, of the latent time in comparison with tests on an untreated control group, and a placebo group injected with Tween 80. There were no significant differences in the average fighting times, but an intensification and de-ritualisation of fighting behaviour can be verified by an increase in the fighting score, significant at the 0.5% level, and in the motor activity, significant at the 1% level. Furthermore, under the influence of hashish in the test situation, a decrease was found in the defecation rate, which was significant at the 0.1% level.