Representative traces of the effects of cumulative doses of risperidone on the CMG and external urethral sphincter EMG of anesthetized rats (n = 7). A & B) CMG after saline administration. C & D) 0.01 mg/kg of risperidone did not affect expulsion time although residual volume was significantly increased (Table 3; Fig 3C). E & F) At 0.1 mg/kg, risperidione caused a reduction in the amplitude of the HFO and the expulsion time. Larger doses of risperidone (1 mg/kg, G & H; 10 mg/kg, I & J) continued to depress the expulsion time and reduced the external urethral sphincter EMG. Note that the HFO were not abolished, unlike the results obtained with olanzapine. Calibration bar: A,C,E,G,I = 1 min; B,D,F,H,J = 1 sec.