Neuroligin-4 KO impairs glycinergic inhibitory synaptic transmission in principal neurons of the MNTB. (A) Measurements of neuroligin-4 mRNA levels from dissected MNTB during development (from P1 to P18, normalized to actin). (B) Illustration of recording strategy from MNTB neurons (left) and sample traces of IPSCs recorded in the absence or presence of strychnine or strychnine and picrotoxin (right). (C) Summary graph of the percentage of the IPSC amplitude that is sensitive to 1 µM strychnine (glycinergic) or to picrotoxin (GABAergic), as recorded from the MNTB of P13–P14 WT mice. (D and E) Sample traces (D) and summary graphs (E) of IPSCs recorded from P14–16 MNTB neurons from littermate control (Nlgn123fl/fl; Nlgn4+/+, gray) and neuroligin-4 KO mice (Nlgn123fl/fl; Nlgn4−/−, red). Data are means ± SEM. Numbers in bars represent the number of cells per the number of mice examined. Statistical significance was determined by Student’s t test (*, P < 0.05; ***, P < 0.001). Ctrl, control.