Fig. 6.

A, I–V series of average patch current from multichannel patches obtained from control or VDH-treated (50 nm, 24–30 hr) neurons. VDH reduced mean current amplitude without altering voltage dependence. Results are mean ± SEM B, Slope conductance of L-VSCCs was unaffected by VDH. Current amplitudes of clearly resolvable single-channel openings (of at least 3 msec duration) were measured from the I–V series. Mean slope conductance for each group was calculated from the average of individual slope conductances.C, Membrane density of functionally available L-VSCCs was reduced by VDH (p < 0.05). Channel density (N per square micrometer) was calculated using the method of maximal simultaneous openings. The membrane area (square micrometers) of a patch was calculated from pipette resistance (see Materials and Methods).