Figure 2.

Tat changes the steady-state voltage dependence of activation of sodium channels. Na⁺ channel activation/inactivation was examined using whole-cell patch-clamp experiments in voltage-clamp mode and a double-pulse protocol in the presence and absence of 100 nm Tat and without Tat (control). Cs⁺ is present in the internal solution to block outward K⁺ current. A, Current density/voltage curve of controls (untreated cells) and Tat-pretreated neurons. B, Boltzmann curve analysis of inactivation and activation of Na⁺ indicates a leftward shift of the activation curve in response to Tat. C, Significant difference in V_0.5 of activation. D, There was no significant difference in V_0.5 of inactivation. *p < 0.05 (t test).