Figure 1. Acute exposure (5 min) to 10 nm T₃ increases I_Na.

A, I_Na was elicited by depolarizing clamp steps from a holding potential of −80 mV to −40 mV. T₃ elicited a reversible increase in peak I_Na (+17 %). B, the current-voltage relationship shows that T₃ significantly increased I_Na at voltages between −40 and +20 mV without affecting peak voltage dependence of I_Na activation or reversal potential. The effects of T₃ were fully reversible.