Fig. 6.

The role of serotonin in promoting patience for future rewards with uncertain timing. a Average waiting time in serotonin no-activation (yellow) and activation (blue) during the D6 test for individual ChR2-expressing (blue thin lines) and WT (green thin lines) mice and for population of ChR2-expressing (blue line) and WT (green line) mice. b Average waiting time in serotonin no-activation (yellow) and activation (blue) during the D4-6-8 test for individual ChR2-expressing mice (gray lines) and for population of mice (blue line). c Average waiting time in serotonin no-activation (yellow) and activation (blue) during the D2-6-10 test for individual ChR2-expressing (blue thin lines) and WT (green thin lines) mice and for population of ChR2-expressing (blue line) and WT (green line) mice. d Average waiting time in serotonin no-activation (yellow) and activation (blue) during the D10 test for individual ChR2-expressing mice (gray lines) and for population of mice (blue line). ***P < 0.001 by paired t-test. Error bars represent the s.e.m. In some case, the error bars are too small to be visible. e Waiting time ratios in the 75% one-pellet tests in which food pellets were delivered with uncertain timing. The waiting time ratio in the D2-6-10 test was the largest among the five tests. The waiting time ratio in the D6 test was not significantly different from the waiting time ratios in the D3 test and in the D10 test. ***P < 0.001 by post hoc Bonferroni correction. Error bars present the s.e.m. n.s. not significant