Fig. 8. (A ) Twin pulse protocol (applied every 4 s) used to study recovery from inactivation. As the interpulse interval, t, was increased (1-ms increments), evoked current amplitudes were proportionately increased (superimposed current sweeps from a control cell are depicted, lower right ). (B ) The recovery from inactivation was well fitted by a single exponential and cOA prolonged the time constant for this process (values given in text).