Electroacupuncture and Brain Protection against Cerebral Ischemia: Specific Effects of Acupoints

Electroacupuncture (EA) has been shown to increase cerebral blood flow (CBF) and reduce ischemic infarction in the rat model of cerebral ischemia (middle cerebral artery occlusion, MCAO). Since multiple acupoints are recommended to treat cerebral ischemia, we performed this study to investigate if there is any variation in EA protection against cerebral ischemia with the stimulation of certain "acupoints" in rats. One hour of right MCAO with an 85% reduction of blood flow induced an extensive infarction (32.9% ± 3.8% of the brain), serious neurological deficits (scale = 6.0 ± 0.5, on a scale of 0-7), and a 17% (10 out of 60) mortality. EA, with a sparse-dense wave (5 Hz/20 Hz) at 1.0 mA for 30 minutes, at Du 20 and Du 26 greatly reduced the infarction to 4.5% ± 1.5% (P < 0.01), significantly improved neurological deficit (scale = 1.0 ± 0.5, P < 0.01), and decreased the death rate to 7% (2 out of 30, P < 0.01). Similarly, EA at left LI 11 & PC 6 reduced the infarct volume to 8.6% ± 3.8% (P < 0.01), improved the neurological deficit (scale = 2.0 ± 1.0, P < 0.01), and decreased the death rate to 8% (2 out of 24, P < 0.01). In sharp contrast, EA at right LI 11 & PC 6 did not lead to any significant changes in the infarct volume (33.4% ± 6.3%), neurological deficit (scale = 6.5 ± 0.5), and the death rate (20%, 5 out of 24). EA at left GB 34 & SP 6, also had an inconspicuous effect on the ischemic injury. EA at Du 20 & Du 26 or at left LI 11 & PC 6 instantaneously induced a significant increase in cerebral blood flow. Neither EA at right LI 11 & PC 6 nor at GB 34 & SP 6 increased cerebral blood flow. These results revealed that the EA protection against cerebral ischemia is relatively acupoint specific.