Figure 4. Blocking effect of nifedipine on LVA Ca²⁺ current in P2 visual cortical neurones.

A, LVA Ca²⁺ current recorded in P2 neurones before (Control) and after blocking by 100 μM nifedipine. The current was obtained by 35 mV step depolarization from a holding potential of -95 mV (top). B, the nifedipine-sensitive component was obtained by subtracting LVA Ca²⁺ current after blocking by 100 μM nifedipine from the control LVA Ca²⁺ current. It was fitted in terms of the m²h model (continuous line) with the inactivation time constant (τ_h) indicated.