[Effects of electroacupuncture stimulation of "Shenmen"(HT 7)-"Taiyuan" (LU 9) on auditory sensory gating P 50 in acute myocardial ischemia rabbits].

OBJECTIVE

To observe the effect of electroacupuncture (EA) stimulation of "Shenmen" (HT 7) and "Taiyuan"(LU 9) on P50 event-related potentials in rabbits with acute myocardial ischemia (AMI), so as to evaluate the specificity of function of different acupoints.

METHODS

Chinchilla rabbits were randomized into normal control, model, Shenmen (HT 7) and Taiyuan (LU 9) groups (n = 10/group). AMI model was established by temporary occlusion of the descending anterior branch of the left coronary artery. EA (1 mA, 2 Hz) was applied to bilateral HT 7 and LU 9 for 15 min. The anesthetized-rabbit's heart rate (HR) was recorded by using a BIOPAC system and the latency and amplitude of auditory sensory gating potential P 50 were measured by paired clicks auditory conditioning (S 1-P 50)/testing (S 2-P 50) stimulus paradigm using a Neuroscan workstation.

RESULTS

In comparison with the normal control group, the HR was significantly decreased in the model group and significantly increased in the HT 7 group than in the model group (P<0. 01). Compared to the normal control group, the amplitude of S 2-P 50 and ratio of amplitude of S 2-P 50/S 1-P 50 were significantly increased in the model group (P<0. 01), and remarkably down-regulated in the HT 7 group than in the model group (P<0. 01),suggesting an inhibitory effect of EA stimulation of HT 7 on cerebral cortical auditory gating potential in AMI rabbits. No significant changes were found in the latencies of S 1-P 50, S2-P 50 potentials in both HT 7 and LU 9 groups and in the HR, amplitude of S 2-P 50 and ratio of amplitude of S 2-P 50/S 1-P 50 in the LU 9 group (P>0. 05).

CONCLUSION

EA stimulation of HT 7 can correct AMI induced decrease of HR and increase of P 50 potential amplitude in AMI rabbits, while EA of LU 9 has no this effect, suggesting a relatively specific effect of different acupoints on cortical sensory gating.