Figure 2.

Measuring operant behavior with the DIY-NAMIC system. A, Reward retrieval training (P1) occurred with presentations of reward available in trials with an ITI average of 45 s. Schematic shows the center reward port is illuminated when the reward is available. B, The number of rewards retrieved over 3 d is shown, separated by light and dark cycle. C, Number of pokes during the ITI when the reward is unavailable is shown over 3 d. D, Schematic for continuous reinforcement training (P2) shows that both side ports are illuminated during a trial, and pokes to either results in reward availability. E, The number of rewards received is shown across the 3 d of training. F, ITI responding is shown over 3 d for each noseport. G, Schematic for P3 which includes trial initiation shows how trials become self-initiated by a poke to the blinking center port. H, Number of self-initiated trials over 4 days of the paradigm. I, Schematic describes the operant cue discrimination paradigm (P4), in which the correct/rewarded port was illuminated by the LED. J, The group average shows that mice perform correctly on 85% of trials and have relatively few incorrect (14%) and omitted (1%) trials. K, The number of trials initiated and the number of correct trials are shown across 24 h, binned by 2 h. The shaded gray area indicates the dark phase of the light cycle. L, Schematic shows the modified two-choice serial reaction time task which was used to assay impulsive action. M, Three-day averages of premature responses per trial over three delay lengths, shown by 2-h bins over the dark cycle. N, Total number of correct, incorrect, and omitted trials on each of 3 d run on three delay lengths. All group averages are shown for N= 9 mice, with error bars representing SEM.