Fig. 2.

A–D: mean ± SE discrimination ratios for object sessions in the Cue Card object recognition (OR), Drop-In OR, and Conventional OR protocols (5-min and 20-min delays). White and gray bars of each graph represent the vehicle- and muscimol-treated groups, respectively. Within the bars, vertical lines represent object discrimination during sample, while diagonal lines indicate object discrimination during the test. Object exploration during sample was equivalent across the treatment groups and mice did not discriminate between the two identical sample session objects. Significant differences between groups were found for the test (all, except Conventional OR protocol, 5-min delay), and these are designated with an asterisk. *P < 0.05 versus vehicle group. Each mouse received bilateral 0.335-µl microinfusion of vehicle or muscimol (1 µg/µl) immediately after acquiring sample exploration criterion (see materials and methods), or in the 5-min delay of the Conventional OR protocol, the treatments were administered 20-min before sample.