Fig. 3.

Properties of RD in response to hyperpolarizing currents of various durations and strengths. A Voltage responses recorded from an MGB neuron to a series of 200-ms hyperpolarizing currents of various strengths from −20 to −140 pA at −20 pA/step. Arrow indicates a graded RD induced by the current at −40 pA. B Responses from the same neuron as in A to a series of hyperpolarizing currents at −40 pA of various durations from 165 to 665 ms. Note that the RD amplitude only slightly increased with current durations longer than 365 ms (arrow). C Typical properties of RD recorded from an MGB neuron as a function of the strength of the hyperpolarizing current with a constant duration (205 ms). D Typical properties of RD recorded from an MGB neuron as a function of the duration of the hyperpolarizing current with a constant magnitude (−100 pA). E Average values for normalized properties of RD as a function of the magnitude and duration of the hyperpolarizing current (n = 7). The measurements are normalized to those of the RD evoked by a 605-ms current at −200 pA.