In vivo Nav1.8 antisense treatment reduces TTX-resistant Na+ current and SA in small primary afferent neurons tested in vitro after SCI. A, Reduction of TTX-resistant current 18–24 h after Nav1.8 ASO injection. Depolarizing steps evoked smaller currents compared with MMO treatment (left and middle). Peak TTX-resistant current was significantly reduced ∼20 h, but not ∼40 h, after the last ASO injection (right). B, ASO treatment decreased the incidence of SA (example in left) 3 d and 1–2 months after SCI (right). Significant suppression from lumbar Nav1.8 ASO injection occurred in lumbar, but not thoracic (T8, T9, T11, T12), DRG neurons.