OBJECTIVETo preliminarily explore the electrophysiological mechanism of acupuncture on plasticity variability of visual cortex.

METHODSFifty 14-day-old Wistar rats were randomly divided into a blank group, a model group, an early-stage acupuncture group, a middle-stage acupuncture group and a late-stage acupuncture group, 10 rats in each one. Except the blank group, the rats in the remaining groups were treated with eyelid suture to establish the model of monocular deprivation amblyopia. After model establishment, the rats in the blank group and model group were grasped without any intervention everyday. The rats in the acupuncture groups were treated with acupuncture at bilateral "Jingming" (BL 1), "Cuanzhu" (BL 2), "Fengchi" (GB 20) and "Guangming" (GB 37) on the 3rd, 12th and 21st days into model establishment. The needles were retained for 10 min, once a day for totally 9 days. After treatment, the M-NEMEA technology was applied to measure the discharge amplitude and power spectral density of visual cortex area 17 neuron of each group.

RESULTSCompared with the blank group, the number of discharged neuron of visual cortex area 17 was reduced, and the amplitude was significantly reduced in the model group (both<0.05). Compared with the model group, the numbers of discharged neuron were increased, and the amplitudes were significantly increased in the early-stage acupuncture group and middle-stage acupuncture group (all<0.05). The neuron discharge amplitude in the early-stage acupuncture group was higher than those in the middle-stage acupuncture group and late-stage acupuncture group (both<0.05); the neuron discharge amplitude in the middle-stage acupuncture group was higher than that in the late-stage acupuncture group (<0.05). In the 120-second time domain of acquisition, the distribution of power spectral density in the blank group was mainly between -105 dB and -100 dB; compared with the blank group, the power spectral density in the model group was increased and distributed between -132 dB and -124 dB; compared with the model group, the power spectral densities in the acupuncture groups was reduced and distributed between -115 dB and -110 dB in the early-stage acupuncture group, -120 dB and -115 dB in the middle-stage acupuncture group and -129 dB and -122 dB in the late-stage acupuncture group.

CONCLUSIONSThere are abnormal changes of spatiotemporal pattern in visual cortex area 17 of monocular deprivation rats, but acupuncture can regulate abnormal spatiotemporal pattern of neuron. Therefore, there is developmental plasticity of visual cortex neuron in the sensitive period, and early treatment is key to superior efficacy.