<p style="text-align: center;">HUANG Jianpeng, LIU Jianhua, JIANG Li</p><p style="text-align: center;">（Guangdong Provincial Hospital，Guangzhou510120，Guangzhou）</p><p style="text-align: justify;"><strong>Abstract</strong>:&nbsp;<strong> Objective</strong>:&nbsp; By observing the change of motor evoked potentials from Hegu acupoint and ora-facial area in the state of pathology, the object is to probe the mechanism of plasticity in across-representation of the cerebral motor cortex, which provides a basic evidence for the Meridian theory.&nbsp; Method:&nbsp; Transcranial magnetic&nbsp; stimulation&nbsp; was&nbsp; applied&nbsp; to&nbsp; the&nbsp; hand-representation&nbsp; and&nbsp; face-representation&nbsp; in&nbsp; motor&nbsp; cortex before and after the forearm ischemic nerve block. Meanwhile,&nbsp; the electromyography records the motor evoked potentials from the First dorsal interosseus and Orbicularis oculi muscle. Results: 1. The MEPs from First&nbsp; dorsal&nbsp; interosseus:&nbsp; the&nbsp; latentperiod&nbsp; is&nbsp; 20.76±0.45&nbsp; ms,the&nbsp; amplitude&nbsp; is&nbsp; 535.26±1.25&nbsp; uV,&nbsp; the&nbsp; Motor threshold is 52.83±9.17%; the MEPs from Orbicularis oculi muscle: the latentperiod is 8.28±0.23 ms,the amplitude is 130.65±0.25 uV, the Motor threshold is 60.0±10.4 %; 2. In pathological conditions, the block of time is 40.61±3.60 minutes.With times’ extending, the area of hand-representation is narrowing.3. The latentperiod and the amplitude are significantly relative to the time of blocking. To dislodge ischemic nerve block, the hand area are recovered.&nbsp; Conclusion：After INB, the MEPs from the target muscles show the changes&nbsp; of&nbsp; the&nbsp; amplitude&nbsp; and&nbsp; the&nbsp; amounts&nbsp; of&nbsp; the&nbsp; stimulated&nbsp; points.&nbsp; It&nbsp; may&nbsp; be&nbsp; one&nbsp; of&nbsp; the&nbsp; biological mechanism of “the specific relation of ora-facial area and Hegu acupoint” in physiological condition.</p><p style="text-align: justify;"><strong>Key&nbsp; words</strong>&nbsp; Acupuncture&nbsp; and&nbsp; moxibustion,&nbsp; the&nbsp; specific&nbsp; relation&nbsp; of&nbsp; ora-facial&nbsp; area&nbsp; and&nbsp; Hegu&nbsp; acupoint, transcranial magnetic stimulation, ischemic nerve block, functional reorganization</p><p><br/></p>