NGF and ischemia: As a result of increases in NGF and expression of NGF's TrkA receptor as well as ASIC3 in DRGs of ischemia limbs, our study further determined if NGF can affect the activities of ASIC currents at pH 6.7 with pre‐application of 100 ng/mL NGF for 24 h (Mamet et al., 2002, 2003).