Fig. 2: Object-recognition memory using optogenetic manipulation.

a Drawings showing two 6-min epochs, the sample epoch (left panel) and recognition epoch (right panel); positions for intermittent photostimulation for 2 s (sky blue); and a novel object (yellow) (adapted from ref. ³³). b Bar plots showing the discrimination ratio (to the novel) during the sample and recognition epochs between Vgat-Cre⁻ (Cre⁻, blue) and Vgat-Cre⁺ (Cre⁺, orange) mice (animal type: F(1, 25) = 3.19, P = 0.09; epoch: F(1, 25) = 15.54, P = 0.0006; interaction: F(1, 25) = 3.44, P = 0.08, two-way mixed-design ANOVA). The discrimination ratio was higher during the recognition epoch than during the sample epoch in Cre⁻ mice (t(12) = 4.45, P = 0.0008, two-tailed paired t test) but not in Cre⁺ mice (t(13) = 1.45, P = 0.2). During the recognition epoch, the discrimination ratio of Cre⁻ mice was higher than that of Cre⁺ mice (t(19.47) = 2.85, P = 0.010, two-tailed Welch’s t test; Cre⁻: t(12) = 8.22, P = 2.8 × 10⁻⁶; Cre⁺: t(13) = 1.07, P = 0.3, two-tailed one-sample t test against zero). c Plots showing no correlation between the total photostimulation time during the sample epoch and the discrimination ratio during the recognition epoch in Cre⁻ (blue) and Cre⁺ (orange) mice (Cre⁻: r = −0.08, t(11) = 0.26, P = 0.8; Cre⁺: r = −0.09, t(12) = 0.30, P = 0.8, Pearson’s product-moment correlation). d Plots showing no correlation between the percentage coverage ratio of photostimulation during the object exploration time in the sample epoch (60.9 ± 2.2%) and the discrimination ratio during the recognition epoch in Cre⁺ mice (r = 0.26, t(12) = 0.92, P = 0.4). Cre⁻ mice (n = 13, 7 females and 6 males, blue) and Cre⁺ mice (n = 14, 10 females and 4 males, orange) in (b–d). ^†††P < 0.005 (main effects and interactions using ANOVA). **P ≤ 0.01 and ***P < 0.005 (two-tailed paired t test and two-tailed Welch’s t test), ⁰P < 0.005 (two-tailed one-sample t test against zero). Bar plots indicate means ±  SEM. Circles and triangles in the graph represent individuals.