Figure 5.

Basal locomotor activity of M₄^−/− receptor mutant mice and their wild-type littermates. (a) Number of total photobeam breaks during a 1-hr observation period (n = 115) studied with vehicle-injected mice. (b) Time course of basal locomotor activity studied with vehicle-injected mice (n > 100 for each data point). Number of total photobeam breaks were measured in 10-min intervals. Locomotor activity measurements were carried out as described in Materials and Methods. Data are given as means ± SEM. ∗, P < 0.05 (Newman–Keuls post hoc comparison).