Fig. 4: In vivo dopamine measurement in DLS following cocaine administration.

a Schematic diagram of in vivo fiber photometry system. b Sample fluorescence (dF/F, % baseline) profile of DA activity in DLS before and after i.p. cocaine injection. c Average fluorescence (dF/F, normalized to session maximum) profile of mice (n = 4) before and after i.p. cocaine injection (left panel), and comparison of the average dF/F between 10 min of baseline and 10 min of cocaine injection (right panel, two-tailed paired t-test **p = 0.0050). d Magnified dF/F profile illustrating DA activity before (Baseline) and after i.p. cocaine injection. e Averaged fluorescence (dF/F, normalized to session maximum) profile of baseline DA transients, time-locked to the transient peaks (n = 64). f Averaged fluorescence (dF/F, normalized to session maximum) profile of DA transients following cocaine injection, time-locked to the transient peaks (n = 165). DA transient g frequency (unpaired two-tailed t-test, p = 0.0002, n = 6 mice) and h amplitude (unpaired two-tailed t-test, p < 0.0001, n = 6 mice) were increased following cocaine injection. Each point denotes a 5 min average of injection. i Average exponential fit of normalized dopamine transient decay. j Fitted exponential decay constant values showing longer DA transient decay time following cocaine injection; individual points correspond to individual transients (n = 52), unpaired two-tailed t-test, p < 0.0001. k dLight fluorescence is blocked by in vivo administration of the D1R antagonist, SCH23390. l Representative dF/F profiles for dLight in DLS before and after SCH23390 administration as well as for an eGFP control mouse. ***p < 0.001. Shaded areas and error bars represent the SEM. Raw data in panels (c), (g), (h), (j) are provided as a Source data file.