Figure 4.

TTX-resistant sodium currents in small DRG neurons are down-regulated after axotomy. (A and B, Left) Whole-cell patch-clamp recordings from representative control (A) and axotomized (B, 6 days postaxotomy) DRG neurons. Note the loss of the TTX-resistant slowly inactivating component of sodium current after axotomy. Steady-state inactivation curves (A and B, Right) show loss of a component characteristic of TTX-resistant currents. (C) Attenuation of TTX-resistant current persists for at least 60 days postaxotomy. (D) Cell capacitance, which provides a measure of cell size, does not change significantly after axotomy (modified from ref. 39).