Fig. 6

SKF increases activity of FSI-PV+ in the striatal microcircuit as seen with Ca²⁺ imaging. a Raster plot of several FSI activity (n = 33 FSI identified from PV-cre mice obtained from 6 different experiments/slices from 3 different mice). Fluorescense induced by Ca²⁺ entry allows infer electrical activity (see Perez-Ortega et al. [6]). Dots in each row of the raster show the activity of a single FSI, at different epochs during the experiment, separated by dashed vertical lines. Left panel: FSI activity in control conditions. Middle panel: addition of 10 µM SKF increases the number of FSI exhibiting spontaneous activity. Note that previous to SKF administration several FSI were silent. Right panel: addition of nicardipine in the continuous presence of SKF reduces the number of active FSI neurons. The experiment demonstrates that DA D1-like receptor activation enhances the number active FSI neurons within the striatal microcircuit in part by facilitating Ca_V1 Ca²⁺ currents. b Summary of cumulative activity from A. c Summary of activity probability in each condition. Note that nicardipine does not completely reverse SKF actions (Friedman ANOVA; F_{2, 64} = 29.63, P < 0.0001; **P < 0.01, ***P < 0.001; with post hoc Dunn’s tests)