is consistent with scRNAseq results indicating that only ~23% of the iN cells express genetic markers for neuronal activity (Fig. 1C). Increased spontaneous and induced spiking (>1–2 spikes) was apparent in the AF group when viewing individual cell responses in a raster plot (Fig. 4B, C). Spiking frequencies increased 2.4-fold in baseline conditions (Fig. 4E; p = 1.1 × 10–6) and 1.3-fold following glutamate stimulation (Fig. 4F; p = 1.6 × 10–3) in the AF group, but no difference was found in KCl-induced activity (Fig. 4G; p = 0.85), confirming the above results from individual neurons. When examining the AF or UN neurons individually, we also observed higher spontaneous and glutamate-elicited excitability for lines 233 and 246 when compared to line 472, which was found to be the least active spontaneously or under glutamate stimulation among the four studied (Supplementary Fig. 6). Overall, cells from the AF KCNJ6 variant haplotype group were more excitable, with no difference in basal physiological properties (i.e., KCl-induced activity). Furthermore, not only did the spike rate increase per cell (bar plots, Spikes/ROI/min), but we also observed increases in the proportion of cells in a field that responded (pie plots). These results not only confirm findings
