Figure 4
The biophysical properties of BK Ca currents are altered in neurons from inflamed rats. BKCa currents from naïve (A) and inflamed (B, CFA) rats were isolated as described in Figure 3. C. To illustrate differences in the rate of current activation, current evoked at +30 mV in the traces shown in A and B have been scaled relative to peak current and overlaid. The time constant for current activation was used to quantify the rise time. D. Pooled data indicate that this difference in activation rate is significant for currents isolated with IbTx and paxilline. E. Deactivation rate was determined from tail currents evoked at −90 mV following BKCa current activation at +30 mV. While there was no apparent difference in the deactivation rate of currents isolated with IbTx between naïve and inflamed neurons (not shown), currents isolated with paxilline appeared to deactivate more slowly in neurons from inflamed rats. Inset: example of IbTx sensitive tail currents used to assess deactivation rate. F. Pooled deactivation rate data (at -90 mV) for BKCa currents isolated with IbTx and paxilline from naive and inflamed rats. ** is p < 0.01