Figure 4. Animal performance in go—no-go odor discrimination or optogenetic discrimination tasks. a, Schematic of cannula implant for light delivery. The cannula was implanted in the OB to stimulate a subset of ventral glomeruli. b, Time course for trials in the odor discrimination or optogenetic discrimination tasks. OV, olfactory valve; FV, final valve; RA, response area; WR, water reward. OV and FA were only used for the odor discrimination task, not for the optogenetic discrimination task. Light is applied as a train of pulses (10 pulses; interval, 250 ms; pulse duration from 10 to 200 ms). c, Percentage correct for go—no-go odor discrimination as a function of block number for six OMP-hChR2V mice. In each block the animal was exposed in 10 trails to the rewarded (S+) odor (1% phenyl acetate) and 10 trials to the unrewarded (S–) odor (1% 2-butanone). Different colors show the results for different mice. d, Percentage correct for go—no-go sessions with rewarded stimulus of optogenetic activation of glomeruli by light (S+, light pulses with 100 ms duration) and the unrewarded stimulus was no activation by light (S–). e, f, Go—no-go for odor discrimination (e) or for optogenetic light activation (f) for three C57BL/6 mice. g, Discrimination of 100 ms pulses (S+) and shorter durations (S−, 10–95 ms) for a representative mouse. h, Discrimination of 100 ms pulses (S+) and longer durations (S−, 200–105 ms) for the same mouse. Two dashed lines show 50 and 80% correct responses, respectively. i, Percentage correct response for the last two blocks of sessions with 100 ms light pulse duration for the S+ stimulus and different light durations for the S− stimulus (average ± SD, n = 6). These points (*) differ from the 95 and 105 ms points in an ANOVA followed up by a post hoc Tukey's HSD criterion (p < 0.05).