FIGURE 5

Inactivation properties of the XE991-sensitive current. (a) Inactivation of the XE991-sensitive current was investigated by a two-pulse protocol described in the inset. Currents were evoked every 60 s. Examples of currents evoked by this protocol in the absence (ai) and presence (aii) of 30  M XE991. XE991-sensitive recordings from the same cell as (a) are shown in panel (bi). An enlargement of the XE991-sensitive currents at V _T (0 mV) is shown in (bii). Panel c shows the mean data from experiments typified in (a). Vertical axis is the mean amplitude of the XE991-sensitive current at V _T normalised to the maximum current at V _T. Horizontal axis is the prepotential (mV). Data points were fitted with a Boltzmann function to give V _1/2 inact=-54.32.1 mV (n=4). Activation data were normalised peak amplitudes at various prepotentials. Data were fitted with a Boltzmann function to give V _1/2=7.12.7 mV (n=4).