Figure 4.

Interval timing in PWScr^m+/p+, PWScr^m+/p−, and PWScr^m−/p− mutants (A) Cartoon of the PI task. The mouse can initiate the trial with a nose poke (NP) in the central hopper (light on for 2 sec) and, to obtain a food pellet, it had to NP in the lateral hopper, after lights off, no sooner than 10 or 30 sec ($T=10$ sec or $T=30$ sec), and no later than 30 or 60 sec, according to the experimental paradigm (see Materials and Methods). Regular and probe trials are shown. The right panel also shows a representative raster plot, and the distribution of start and stop times of NPs in probe trials. (B) Distribution of the response (NP) rate in probe trials ($T=10$ sec on the left panel, and $T=30$ sec on the right panel). (C) STARTs and STOPs for the PWScr^m+/p+ (n = 6), PWScr^m+/p− (n = 6), and PWScr^m−/p− (n = 5) are shown for the two 10-sec and 30-sec FI–PI schedules. Graphs are presented as the mean $\pm$ SEM. The cross notation mark above the asterisks in the bars represent the one-way ANOVA between groups, while the asterisks represent post hoc significance ($P<0.05$) corrected by Holm’s correction.