Figure 2

Phase shift behavior of Per1 ^−/− /Pml ^−/− mice. Mice were entrained to a 12 h light/12 h dark cycle (LD) and a light pulse was given on the last day of LD at ZT 14 or ZT 22. (A) &(B) Phase delay response to a ZT14 light pulse (15 min) of wild type, Per1 ^−/− , Pml ^−/− and Per1 ^−/−/Pml ^−/− mice. (C) &(D) Phase advance response to a ZT22 light pulse (15 min) of wild type, Per1 ^−/− , Pml ^−/− and Per1 ^−/−/Pml ^−/− mice. Error bar indicates SEM. p < 0.05, (n = 9).