Whole-cell patch-clamp recordings from dissociated hCSs were performed at room temperature in an isotonic saline solution (NaCl 125 mM, NaHCO3 25 mM, KCl 2.5 mM, NaH2PO4 1.25 mM, glucose 25 mM, MgCl2 1 mM, CaCl2 2 mM). Patch electrodes with resistances of 2.5–3.5 MΩ were pulled from thick-walled borosilicate glass capillaries and were filled with an internal solution containing potassium gluconate 130 mM, NaCl 4 mM, EGTA 5 mM, CaCl2 0.5 mM, HEPES 10 mM, MgATP 4 mM, Na2GTP 0.5 mM (pH 7.2 with KOH). Voltage-gated sodium and potassium currents were elicited with a series of voltage steps (from −110 to 10 mV, in 20 mV increments) from a holding potential of −70 mV. Spontaneous synaptic transmission was monitored in voltage-clamp from a holding potential of −70 mV. Action potentials evoked in response to current injection were recorded from the resting potential of the cell (applying 20 pA steps for 200 ms). Series resistance was monitored throughout the recording and was <20 MΩ. NBQX (25 μM, Tocris) and D-AP5 (50 μM, Tocris) were used to inhibit AMPA-receptor mediated and NMDA-receptor
