Lithium attenuates clonidine-induced hypoactivity: further studies in inbred mouse strains.

Four strains of mice (C57, BALB, DBA, C3H) were used to determine whether genetic factors influence the effects of lithium on hypoactivity induced by a low dose of the alpha 2-adrenoceptor agonist clonidine (0.2 mg/kg). Lithium was administered in the diet for 3-4 weeks at a dosage that produced average serum lithium levels of 0.58-0.66 mmol/l. Locomotor activity was reduced by either clonidine or by lithium given alone. When combined, however, lithium attenuated the activity-suppressant effects of clonidine, and that action was influenced by genetic factors. The findings suggest that genetic differences in alpha 2-adrenoceptors play a role in behavioural effects of lithium.