Fig. 6

L5PN → Aldh1a1 synaptic transmission mediates delay of gratification. a, Representative images show the expression of Gi-ChR2 in L5PN (L5PN^Gi-ChR2 mice). b, The illustration shows whole-cell patch-clamp recordings from GFP-expressing Aldh1a1 neurons and chemogenetic inhibition of L5PN axon terminals. c, EPSCs were recorded from GFP-expressing Aldh1a1 neurons and evoked by blue laser light stimulation on axon terminals of L5PN^Gi-ChR2 in the slices. The plot shows the mean amplitudes of EPSCs versus the time of the individual (circles) recordings in the slices from L5PN^ChR2 mice (black) or L5PN^Gi-ChR2 mice (red) and the averages of the recordings 5 min from the baseline or the presence of CNO (mean ± SEM, n = 12 recordings/6 mice/group). d, Chemogenetic inhibition of L5PN outputs to Aldh1a1 neurons reduces the behavioral preference for LDR in the probe trials. The plot shows the percentage of the correct trials with the behavioral options for SIR or LDR of L5PN^tdT mice with CNO (blue) or L5PN^Gi mice with CNO (green) or saline (red) at each day of the probe trials (mean ± SEM, n = 9 mice per group). e, The chemogenetic inhibition of L5PN output to Aldh1a1 neurons reduces the percentage of LRA visiting. The plot shows the percentage of LRA visits at a delay of 0-3 s (blue) or 6-9 s (red) from individual (circles) L5PN^tdT mice with CNO or L5PN^Gi mice with CNO or saline and the averages per group (triangles, mean ± SEM, n = 11 mice/group) at day three of the testing sessions. f, Generation of a mutant line of mice with the expression of Gi in L5PN (L5PN^Gi) and ChR2 in Aldh1a1 neurons (Aldh1a1^ChR2). g, Optogenetic activation of Aldh1a1 neurons counteracts the effects of L5PN synaptic inhibition in delay of gratification. The plot shows the percentage of the correct trials with the behavioral options for SIR or LDR of L5PN^tdT-Aldh1a1^ChR2 (blue), L5PN^Gi-Aldh1a1^GFP (green), or L5PN^Gi-Aldh1a1^ChR2 (red) mice at each day of the probe trials (mean ± SEM, n = 9 mice per group). In this study, CNO and blue laser light were delivered onto the VTA during the probe trials. h, The plot shows the percentage of LRA visits at a delay of 0-3 s (blue) or 6-9 s (red) from the individual (circles) L5PN^tdT–Aldh1a1^ChR2, L5PN^Gi-Aldh1a1^GFP, or L5PN^Gi-Aldh1a1^ChR2 mice and the averages per group (triangles, mean ± SEM, n = 11 mice per group) at day three of the testing sessions. All statistical data are summarized in Supplementary Table 1.