Dopamine D 1 antagonists potentiate the durations of bar and cling catalepsy and the dorsal immobility response in rats

Abstract

The effects of dopamine D 1 antagonists SCH 23390 or SK&F 83566 (at SC doses of 0.00, 0.01, 0.05, and 0.1 mg/ kg) were tested for 2 h on bar and cling catalepsy and the dorsal immobility response. Each of the drugs potentiated the duration of each of the three measures of immobility in a dose- and time-dependent manner. Each of the drugs had rapid but brief effects on all three response measures; the peak effect of SK&F 83566 took place at 20 min and that for SCH 23390 at 40 min for each behavior. At each effective drug dose, SCH 23390 had a greater effect than SK&F 83566 on each behavior. Dopamine D 1 antagonists potentiated three different immobility responses, as do dopamine D 2 antagonists.