OBJECTIVE: To investigate the relationship between the temperature and the microvascular blood flow of the cerebral cortex, and the influence of electro-acupuncture (EA) on the cortical microcirculation. METHODS: High temperature spots on the anterior ectosylvian and low temperature spots on the posterior suprasylvian on the cortical surface of 20 cats were identified using cortical infrared thermography (CIT); the blood flow in the microcirculation on these spots was measured with laser-Doppler flowmetry. EA was given at Zusanli (ST 36) and changes in the blood flow in the cerebral cortex microcirculation were detected. RESULTS: 1) The mean temperatures on the high (34.83 +/- 0.24 degrees C) and low (32.28 +/- 0.27 degrees C) temperature spots were significantly different (P < 0.001); this was indicative of a temperature difference on the cortical surface; 2) The average blood flow in the microcirculation of the high (266.8 +/-19.2 PU) and low (140.8 +/- 9.9 PU) temperature spots was significantly different (P < 0.001). 3) On the cortical high temperature spots, the mean blood flow in the microcirculation significantly increased from 266.8 +/- 86.8 PU before EA, to 422.5 +/- 47.4 PU following 5 minutes of EA (58.35%; P < 0.01), and 431.8 +/- 52.8 PU 5 minutes after ceasing EA (61.84%; P < 0.01). 4) On the low temperature spots, there were no significant differences in blood flow following 5 minutes of EA (146.3 +/- 11.5 PU), and 5 minutes after ceasing EA (140.5 +/- 11.6 PU), when compared with that before acupuncture (140.8 +/- 9.9 PU; P > 0.9). CONCLUSION: The high temperature spots of the cortex are active functional regions of neurons with higher blood flow and a stronger response to EA. EA induces a significant increase in blood flow in the high temperature spots of the cortex.
OBJECTIVE: To investigate the relationship between the temperature and the microvascular blood flow of the cerebral cortex, and the influence of electro-acupuncture (EA) on the cortical microcirculation. METHODS: High temperature spots on the anterior ectosylvian and low temperature spots on the posterior suprasylvian on the cortical surface of 20 cats were identified using cortical infrared thermography (CIT); the blood flow in the microcirculation on these spots was measured with laser-Doppler flowmetry. EA was given at Zusanli (ST 36) and changes in the blood flow in the cerebral cortex microcirculation were detected. RESULTS: 1) The mean temperatures on the high (34.83 +/- 0.24 degrees C) and low (32.28 +/- 0.27 degrees C) temperature spots were significantly different (P < 0.001); this was indicative of a temperature difference on the cortical surface; 2) The average blood flow in the microcirculation of the high (266.8 +/-19.2 PU) and low (140.8 +/- 9.9 PU) temperature spots was significantly different (P < 0.001). 3) On the cortical high temperature spots, the mean blood flow in the microcirculation significantly increased from 266.8 +/- 86.8 PU before EA, to 422.5 +/- 47.4 PU following 5 minutes of EA (58.35%; P < 0.01), and 431.8 +/- 52.8 PU 5 minutes after ceasing EA (61.84%; P < 0.01). 4) On the low temperature spots, there were no significant differences in blood flow following 5 minutes of EA (146.3 +/- 11.5 PU), and 5 minutes after ceasing EA (140.5 +/- 11.6 PU), when compared with that before acupuncture (140.8 +/- 9.9 PU; P > 0.9). CONCLUSION: The high temperature spots of the cortex are active functional regions of neurons with higher blood flow and a stronger response to EA. EA induces a significant increase in blood flow in the high temperature spots of the cortex.