Fig. 6.
Roscovitine (Rosc)-induced slowed deactivation reveals functional CaV2 channels in the presence of GVIA and AgaIVa. All currents were recorded in 5 mM Ba2+. A: a muscle afferent neuron shows the effect of Rosc on CaV2 currents (no toxins present). Rosc (100 μM) slowed deactivation (black trace) compared with Cntl and recovery (Recov; gray traces). B: current traces from the same muscle afferent neuron as shown in A recorded in 10 μM GVIA and 0.2 μM AgaIVa. Rosc (100 μM) (black trace) slowed deactivation compared with Cntl (Toxin) and Recov (gray traces). C: a single exponential equation was fit to the deactivating currents at −40 mV to determine the deactivation τ in presence of toxin (GVIA and AgaIVa) and toxin + 100 μM Rosc. The average deactivation τ (±SD) is shown. *Significant slowing of deactivation induced by Rosc. The number of muscle afferent neurons tested is indicated in the middle bar.