Fig.3

Hyperexcitability and spiking irregularity in hippocampal neurons expressing LGI1^W183R. A Schematic of whole-cell recording in cKO CA1 pyramidal neurons expressing LGI1^WT-GFP or LGI1^W183R-GFP (pip: patch pipette). B AP evoked by a rheobase current (black), but not subthreshold currents (grey) (arrows, threshold, RMP, amplitude, and half-width. C Averages of membrane capacitance (Cm) and rheobase. D Left: example APs in cKO::LGI1^WT and cKO::LGI1^W183R neurons. Right: phase-plane plots for APs. The arrowheads show the measurement of threshold and dV/dt at 0, + 20 (repolarization) and − 40 mV. E Averages of RMP, threshold, half-width, amplitude, dV/dt at 0 mV, dV/dt at + 20 mV, and dV/dt at − 40 mV. F Left: example APs induced by rheobase current in cKO::LGI1^WT and cKO::LGI1^W183R neurons. Right: probabilities of doublet APs. G Left: example spikes recorded in cKO::LGI1^WT and cKO::LGI1^W183R neurons responding to 80-pA and 200-pA currents. Right: numbers of spikes as a function of injected currents. H Left: representative 1st and last spikes induced by 200-pA current. Middle: half-widths of 1st spikes induced by different currents plotted against to currents. Right: ratios of last vs 1st spikes were plotted against corresponding currents. I Left: example firing showing spike-timing reliability. Right: plots of intraburst jitters as a function of recording time. J Averages of 1^st ISI frequency, CV, and CV₂. K Left: example AHPs. Right: plots of fast AHP as a function of spikes. Insets amplification of 2^nd and 4^th AHPs. See Additional file 8: Table S3 for statistics. Grey dots indicate individual data points. *P < 0.05. ** P < 0.01. *** P < 0.001