Figure 6. Depolarization-induced slowing of deactivation with submaximally active GABA applications.

A, example of traces from a cell where 20 μM GABA was applied for 120 ms at holding potentials of between −70 and +50 mV. The membrane potential was incremented in 10 mV steps and an agonist application was made every 10 s. The inset shows the peak current-voltage relationship pooled from 12 such experiments; data at each potential were normalized to the current amplitude at −70 mV (error bars are partially obscured by the symbols). B, normalized mean activation trajectories (left) and deactivation trajectories (right) recorded at holding potentials of −70 and +50 mV. Data from 12 recordings, like that in A. Before being included in the overall mean, each sweep was normalized to the current amplitude observed at the point of GABA removal. Error bars from the averaging procedure are shown at occasional intervals. Note that the initial rates of deactivation at −70 and +50 mV appear very similar (asterisk).