Influence of the cannabinoid agonist HU 210 on cocaine- and CQP 201-403-induced behavioural effects in rat

Acute injection of the cannabinoid agonist HU 210 (6.25-100 mu g/kg, i.p.) dose-dependently inhibited rat locomotor activity and rearing, while subchronic treatment with the drug (once daily for 7 days) at the same doses only diminished locomotion. Acute but not subchronic administration of HU 210 (12.5-50 mu g/kg, i.p.) potently counteracted acute and subchronic cocaine (15 mg/kg, i.p.)- induced hyperlocomotion and enhanced rearing. The acute cannabinoid (6.25-100 mu g/kg, i.p.) also inhibited locomotor activity, stereotyped behaviour and shaking elicited by the D-1/D-2 agonist CQP 201-403 (500 mu g/kg, i.p.). On the contrary, subchronic treatment's with HU 210 enhanced CQP 201-403-induced locomotor activity and potently stimulated escape attempts. Discussion centers on the influence of cannabinoids on experimental models of psychosis.