Electroacupuncture modulates cortical activities evoked by noxious somatosensory stimulations in human.

A noninvasive high-resolution imaging technique of cerebral electric activities has been developed to directly link scalp potential measurement with the magnetic resonance images of the subjects, which is very helpful for the elucidation of the cortical processing following various stimulations. Here, we used a 64-channel Neuroscan ESI-128 system to explore the specific cortical activities elicited by electroacupuncture (EA) acupoint in normal volunteers and the modulatory effect of EA on cortical activities evoked by noxious somatosensory stimulation. A specific later-latency somatosensory-evoked potential (SEP, P150) located in bilateral anterior cingulated cortex was observed after EA acupoint but not non-acupoint. Two pain-specific SEP components (P170 and N280), located in bilateral suprasylvian operculum and anterior cingulated cortex respectively were observed following painful median nerve stimulation. Binding EA acupoint with painful median nerve stimulation, the amplitudes of P170 and N280 appeared to be attenuated significantly, 2D topography exhibited tremendous decrease of cortical activation between 120 ms and 296 ms in latency, and visual analogue scale (VAS) changes also showed a similar pattern to the change of amplitude. The bilateral anterior cingulated cortex recruited following acupoint stimuli might, to some extent, suggest that EA has the specific physiological effects. Decrease of pain-induced cortical activation by EA acupoint was considered to be mainly due to an interaction of the signals in anterior cingulated cortex ascending from the pain stimulation and EA.

[Effect of electroacupuncture at "Neiguan" (PC 6) on expression of c-fos gene in myocardium of the rat with acute myocardial ischemia].

OBJECTIVE: To explore the mechanism of electroacupuncture at "Neiguan" (PC 6) improving acute myocardial ischemia. METHODS: The rats were randomly divided into a sham operation group, a myocardial ischemia model group and a myocardial ischemia model plus electroacupuncture group. The acute myocardial ischemia model was developed byligation of the descending anterior branch of the coronary artery, and electroacupuncture was given at bilateral "Neiguan" (PC 6). Serum myocardial enzymes was determined by biochemical method and the expression of c-fos mRNA in myocardium was detected by using reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The activities of serum myocardial enzymes and the expression of c-fos mRNA in ischemic myocardium were significantly increased as compared with those in the sham operation group (P < 0.05), and after electroacupuncture they were significantly decreased (P < 0.05). CONCLUSION: The mechanism of electroacupuncture at "Neiguan" (PC 6) improving acute myochadial ischemia is possibly related with down-regulation of expression of c-fos mRNA in myocardium.