Figure 4.

Early functional maturation is modified in Dcx ShRNA⁺ newborn cells (5–7 dpe). A, Electrophysiological properties of newly generated cells were assessed by whole-cell patch-clamp recordings in three different regions with respect to the rostrocaudal axis (RMS1, RMS2, core OB). Membrane capacitance (C_m), membrane resistance (R_m), and maximum density of voltage-dependent K⁺ channel-mediated currents (I_K⁺) were measured. No significant differences were observed between control and Dcx ShRNA⁺ cells. In contrast, the maximum density of voltage-dependent Na⁺ channels (I_Na⁺) was significantly increased in Dcx ShRNA⁺ cells located in the core of the OB. B, GABA receptor (GABA-R)-mediated peak current amplitudes (I_GABA) were measured after bath application of muscimol (25 μm) at 0 mV. Calibration: 20 s, 10 pA. C, Non-NMDA glutamate receptor (GluR)-mediated peak current amplitudes (I_GLUT) were measured after bath application of kainic acid (50 μm) at −60 mV. Note that the GABA-R-mediated current is significantly increased in Dcx ShRNA⁺ cells in the RMS2 and in the core of the OB, although the amplitude of GluR-mediated currents remains constant. All cells were recorded between 5 and 7 dpe. Groups were compared 2 by 2 using a Mann–Whitney test (**p < 0.01, ***p < 0.001). Calibration: 2 min, 10 pA.