Figure 4.

A. Traces correspond to patch clamp recordings (voltage clamp mode) from 2–3 month old 6 CON (glut3^{flox/flox/Emx1-Cre-}) and 4 KO (glut3^{flox/flox/Emx1-Cre+}) mice and their cortical pyramidal neurons (CPNs) after 7–9 min of GABA_A receptor antagonist bicuculline (10 μM) application. While all CPNs from KO mice displayed paroxysmal discharges, 4 out of 11 cells from CON mice did not generate discharges and the remainder displayed discharges after long latencies. In addition, discharges from KO mice were more complex (e.g., “doublets”) (see B panel). (CON, n=11 cells from 6 mice; KO, n=11 cells from 4 mice). Total paroxysmal events: CON=15, KO=54. B. While paroxysmal discharges only exceptionally occurred before 7–9 min in CON cells, many KO cells showed paroxysmal activity within the first 5 min after bicuculline (GABA inhibitor) application. Notice also that this cell displayed a complex discharge (“doublet” discharge plus action potential in between) just 3.3 min after bicuculline. C. Events/min of paroxysmal discharges were increased in KO mice when compared to CON mice, *p=0.01. D. Mean latency to the first paroxysmal discharge was significantly decreased in CPNs from the KO group when compared to the CON group (p=0.015, 7 CON and 11 KO).