Fig. 2

Behavioral tests related to hippocampus-dependent learning and anxiety in Trpm2^−/−mice. (a) Experimental procedure for the novel object recognition (NOR) test. (b) NOR test. Trpm2^−/− mice had the same discrimination index as WT mice 100 min and 24 h after training (2 h, t₍₂₇₎ = 1.265, p = 0.2165; 24 h, t₍₂₇₎ = 1.149, p = 0.2607; WT, n = 13; Trpm2^−/−, n = 16). (c) Time line of the CFC and extinction procedure followed in the OFT (d, e, f) and the EPM (g, h). Spontaneous motor activity and anxiety levels are not changed in Trpm2^−/− mice. Spontaneous motor activity as indicated by total distance moved and speed of mice were also not changed in the Trpm2^−/− mice (d, e; detailed statistics in Supplementary Information). Also, anxiety was not altered in the Trpm2^−/− mice, as there were no differences in the time animals spent in the central zone of the arena in the OFT (f), the number of open arm entries/total entries (g) and the time spent freezing in the open arm (h) in the EPM for 5 min (detailed statistics in Supplementary Information). Data are expressed as mean ± SEM