Figure 2

Decreased activity of CS-KO mice in the tests for anxiety-like behavior. In the open field test (A), time spent in center was not significantly different between genotypes during the whole 120 min period. However, in the first 60 min of the trial, CS-KO mice spent significantly less time in the center of the field (Aa). The total distance traveled was not significantly affected by the lack of CS (Ab). Stereotypic counts were not significantly different between genotypes (Ac). No significant difference was detected between genotypes in vertical activity (Ad). During a social interaction test in a novel environment (B), the number of contacts (Ba) and the total duration of active contacts (Bb) of CS-KO mice were significantly smaller than those of WT mice. However it is possible that this is due to decreased locomotor activity of the CS-KO mice in this test (Bc). The mean duration of contact (Bd) and total duration of contacts (Be) in CS-KO mice did not differ significantly from that of WT mice. In the elevated plus maze (C), CS-KO mice showed a significant decrease in number of entries (Ca), and tendency of decrease in distance traveled (Cc). Neither percentage entries into open arms (Cb) nor time on open arms (Cd) was affected by the lack of CS. (*) Significantly different during first 60 min block in genotype effect, P < 0.05. Data are expressed as mean ± S.E.M.