Fig. 4: Initiation of sniffing by DA release into the ventral striatum.

a Schematic of optogenetically-evoked sniffing paradigm. Control mice received AAV-Ef1α-DIO-EYFP. Some aspects created in BioRender. Wesson, D. (2024) https://BioRender.com/j05r121. b Optic fiber locations. c Respiration from a mouse across repeated trials of optogenetic stimulation in TuS (1 s long, 25 Hz, blue horizonal line). Raw is on left, with corresponding across-trial data on right. d 2-dimensional histograms across all mice tested (n = 11 TuS, 6 NAcSh and NAcC, 9 EYFP), showing individual trial data within mice. Example data from (c) denoted by the white star. e Mean Hz ± SEM during photostimulation. f Mean frequency ± SEM of photostimulation-evoked sniffing. Group colors as in (e). g Outcomes of optogenetically-evoked sniffing during 1 s photostimulation. All data presented as mean ± SEM, points = individual mice. ****p < 0.0001, ***p < 0.001, **p < 0.01 (ANOVA with multiple comparison correction, see Results for actual p values). gi Mean latency with animals that failed to reach 6 Hz on > 40% of trials excluded from the EYFP group. gii Mean percentage of time spent sniffing. giii Max sniffing frequency. giv Mean probability that photostimulation evoked sniffing. h Mean respiratory frequency during different photostimulation durations (100 ms, 1 s, 2 s, 4 s) compared to that of controls stimulated for 1 s in the TuS (hi), NAcSh (hii), and NAcC (hiii). Insets = percentage of time across all groups, calculated in a 4 s window. In all panels when depicting a singular bar with whiskers, data are mean ± SEM. Individual data points = individual mice. Source data are provided as a Source Data file.