The 5-HT1A receptor–Kir3 channel pathway mediates the amplified 5-HT electrophysiological response in mice with 5-HTT disruption. Representative recordings (A) and scatterplot (B) of the 5-HT response before and after application of the 5-HT1A antagonist, WAY100635 (30 nm) in within-cell paired recordings from 5-HTT HET (n = 5) and PN-Flx (n = 7) neurons. C, Representative Western blot (top) and quantification (bottom) showing prefrontal protein levels of 5-HT1A receptor (n = 4 each group). D, The 5-HT1A current before and after application of the Kir3 channel blocker tertiapin Q (0.1 μm) and washout (10–20 min) in neurons from WT (n = 6) and HET mice (n = 5). Representative Western blots (top) and quantification (bottom) showing prefrontal protein levels of Kir3.1 (E), Kir3.2 (F), and Kir3.4 (G) in WT (n = 8 or 9) and HET mice (n = 8–10). *p < 0.05. **p < 0.01.