Figure 2. Intrinsic membrane properties are not changed in NRXN1-mutant iN cells.

(A) Summary graphs of the passive membrane properties (left, capacitance; middle, input resistance; right, resting membrane potential) of control and NRXN1-mutant iN cells derived from the NRXN1 cKO (A1) or the cTr#2 line (A2).

(B) Neuronal excitability in control and NRXN1-mutant iN cells is unchanged. Left, representative traces of action potentials induced by step current injections (from −5 pA to +50 pA); right, intensity-frequency plots in the number of action potentials as a function of step current injections (B1, cKO line; B2, cTr#2 line).

(C) Representative traces of spontaneous action potentials recorded from control and NRXN1 mutant iN cells.

(D) Summary graphs of action potential properties in control and NRXN1-mutant iN cells (left, firing threshold; middle, action potential amplitude; right, spontaneous firing frequency).

(E) Voltage-dependent Na⁺ (I_Na⁺) and K⁺ (I_K⁺) currents are unchanged. Representative traces are shown on top (insets = Na⁺ currents on an expanded time scale), and current/voltage plots at the bottom. Currents were recorded in voltage-clamp mode; cells were held at −70 mV; stepwise depolarization from −90 mV to +20 mV at 10 mV intervals was delivered.

‘1’ and ‘2’ panels depict data for the NRXN1 cKO and the cTr#2 line, respectively. For data from the cTr#1 line, see Fig. S5. All summary data are means ± SEM (number in bars or brackets show number of cells/cultures analyzed).