Fig. 4. Representative tetrodotoxin-resistant (TTX-R) and tetrodotoxin-sensitive (TTX-S) Na⁺currents traces recorded in the small neurons from a sham-operated dorsal root ganglion.  A–C : Representative current-voltage (I-V) curve family of currents recorded in the absence of tetrodotoxin, using the prepulse protocols (  inset );  A , the total Na⁺current;  B , the TTX-R Na⁺current;  C , the TTX-S Na⁺current.  D : Representative records of the steady-state inactivation of TTX-R and TTX-S Na⁺currents.