LOW-DOSE AMPHETAMINE ELEVATES MOVEMENT-RELATED FIRING OF RAT STRIATALNEURONS

To study the striatal role in amphetamine's stimulant effects on motor behavior, single neurons were recorded in the dorsolateral striatum o f unrestrained rats before and after amphetamine injection (0.5 or 1.0 mg/kg, i.p.). Comparisons of firing were made between similar motor b ehaviors before and after injection. Mean locomotor firing rates incre ased 5% to 276% within 30 min after injection and reversed within 2 h. Firing related to specific head- or forelimb-movements, which were si milar in all measured parameters before and after injection, was eleva ted several hundred percent after injection and then reversed, the tim e course paralleling that of the stimulant effect on these movements. Elevation of movement-related striatal firing rates by low doses of th e psychomotor stimulant is in line with established increases in firin g rate normally observed for striatal neurons related to motor behavio r.