Electroacupuncture Promotes Neuroplasticity of Central Auditory Pathway: An Auditory Evoked Potentials Study

Our previous studies found that electroacupuncture at the right Zhongzhu acupoint (TE3) can enhance auditory recovery in rats with noise-induced hearing loss. Here, we investigated the changes in auditory brainstem response (ABR) and long late latency (LLR) evoked potential to explain the mechanisms of electroacupuncture at TE3. The auditory evoked potentials were recorded, including ABR and LLR, at baseline and on day 3 (D3), D5, and D8 after baseline. The 2-Hz electroacupuncture at the right TE3 was applied on D3, D4, and D5 in the electroacupuncture group but not in the control group. In ABR, compared with the control group, the latency shift of waves I (0.298 ± 0.033 vs -0.045 ± 0.057 ms), III (0.718 ± 0.038 vs -0.163 ± 0.130 ms), and V (1.160 ± 0.082 vs -0.207 ± 0.138 ms) on D3 (all p  <  0.01) and of wave V (0.616 ± 0.433 vs -0.352 ± 0.209 ms, p  <  0.05) on D5 was greater in the electroacupuncture group than that in the control group. Moreover, the interpeak latency shift of I-III (0.420 ± 0.041 vs -0.118 ± 0.177 ms) and I-V (0.863 ± 0.088 vs -0.162 ± 0.156 ms) on D3 (both p  <  0.05) and of III-V (0.342 ± 0.193 vs -0.190 ± 0.110 ms) and I-V (0.540 ± 0.352 vs -0.343 ± 0.184 ms) on D5 (both p  <  0.05) was greater in the electroacupuncture group than that in the control group. In LLR, the latency shift of P0 was greater in the electroacupuncture group than in the control group on D3 (3.956 ± 2.975 vs -1.178 ± 1.358 ms, p  <  0.01) and D5 (2.200 ± 1.889 vs -0.311 ± 1.078 ms, p  <  0.05). These findings indicate that electroacupuncture at the right TE3 can modulate the neuroplasticity of the central auditory pathway, including the brain stem and the primary and secondary auditory cortex.