Fig. 1.

LSd^Sst neurons are activated in response to diverse stressors. (A) Schematics showing Cre-dependent expression of GCaMP6 and fiberoptic cannula implantation for fiber photometry recordings from LSd^Sst neurons. Representative confocal images show LSd- restricted expression. Scale bar, 200 µm. (B) Schematic of the fiber photometry system. (C) Velocity of mice was only weakly correlated with the activity of LSd^Sst neurons (n=7, Pearson’s r=0.244, p=0.08). (D) Spatial calcium activity map of a representative mouse showing the higher activity of LSd^Sst neurons in the center zone of the open field arena. Average normalized calcium responses are color-coded for each pixel of spatial location. (E) Average calcium activity of LSd^Sst neurons in the center and the periphery (n=7, p=0.03). (F) Peri-event plot showing increases in the activity of LSd^Sst neurons as mice approach and enter the center zone. (G) Representative calcium response heatmap showing increased activity of LSd^Sst neurons in the open arms of the elevated plus maze. (H) Average calcium activity of LSd^Sst neurons for open arms (Open) was higher than for closed arms (Closed) (n=5, p=0.008). (I) Peri-event plot showing increases in the activity of LSd^Sst neurons as mice approach and enter open arms. (J) Representative traces showing increased activity of LSd^Sst neurons during the baselines and physical restraint. (K) Calcium transient amplitudes of LSd^Sst neurons were increased by restraint (n=5, one-way repeated measures ANOVA interaction, F(2,8)=19.65, p=0.0008). HC, homecage; Res, restraint. (L) Mice were given a series of electric footshocks. (M) Average calcium transients around the shock show time-locked responses of LSd^Sst neurons (n=5). Shaded box, footshock. (N) Average normalized calcium responses of both LSd^Sst neurons to shock delivery (Shock, 0~2 s from the shock onset) were larger than activity level during rest of the session (Base) (n=5, p=0.008). Data are represented as mean±s.e.m. Asterisks indicate significance levels for comparisons in each panel using Bonferroni post-tests following one-way repeated measures ANOVA or Wilcoxon rank-sum test (*p<0.05, **p<0.01).