Table 1. Increased locomotor activity in PRS mice is reduced by clozapine but not haloperidol.

Treatment	Horizontal activity (Counts per 15 min)
	NS	PRS
Vehicle	3656±182	4229±132a
Haloperidol	3323±226	4040±223
Clozapine	3538±147	3866±217b

^aP<0.05 when vehicle-treated PRS mice are compared with vehicle-treated NS mice.

^bP<0.05 when clozapine-treated PRS mice are compared with vehicle-treated PRS mice. One-way analysis of variance (F_5,30=4.0, P=0.002) followed by Student–Newman–Keuls multiple-comparison procedures.

Seventy-five-day-old PRS (prenatally stressed) or NS (nonstressed) male mice were subjected to locomotor activity test and divided in groups of six mice with comparable locomotor activity values. Mice were then treated subcutaneously, twice a day for 5 days, with vehicle, 5mg kg⁻¹ clozapine or 1 mg kg⁻¹ haloperidol, respectively. The locomotor activity was measured again on the sixth day, 18 h after the last treatment. The data are expressed as mean±s.e.m. of six mice per group.