感觉运动皮层的锥体束通路对NRM电针镇痛效应的影响

感觉运动皮层可通过锥体束及锥体外系对躯体运动进行控制。本实验证明大鼠感觉运动皮层也可通过锥体束对痛觉进行调制。锥体束切断后可明显增强电针“足三里”的镇痛作用。表明锥体束完整的情况下对电针的镇痛效应有拮抗作用。这可能是患者情绪急躁全身肌肉紧张时,针刺疗效不佳的机制之一。

THE INFLUENCE OF PYRAMIDAL TRACT PATHWAY OF SENSORIMOTOR CORTEX ON THE EFFECTS OF ACUPUNCTURE ANALGESIA ON NRM NEURONS

The experiment was to study whether the effects of electroacupuncture (EA)on neurons in nucleus raphe magnus (NRM)were influenced after lesion of bila- teral pyramidal tracts (PT) in the rats.unit discharges of NRM were recordedextracellularly with glass microelectrodes,and their nociceptive responses wereinduced by train electro-stimulation of tail.It was researched only the neuronswith excitory response to noxious stimulation of the tail.1.The effects of bilateral ‘Zusanli’ acupoint on 31 NRM neurons wereobserved in control group.EA had a tendency to activate NRM neurons,butinhibited obviosly nociceptive response of the neurons at 0-30 minutes (P<0.01).The effects of EA of PT control group (PT exposed and kept intact) wererecorded on 8 units in NRM.EA had a tendency to activate the neurons,butinhibited obviously nociceptive response of the neurons and decreased nocice-ptive response rate 25.3±8.7% at o minte (n=8,P<0.05)3.EA after the PT lesion,it obviously inhibited nociceptive response ofthe neurons in NRM at 0-20 minutes (n=9,P<0.01-0.05).It inhibited noci-ceptive ressponse of all the neurons and decreased noeiceptive response rate57.8±11.6% at o minute (P<0.01).The effect was larger than the effect ofEA of PT control group and increased 32.5% at o minute (P<0.05) than this.It also increased the effect of EA activating the neurons than PT control group.The results suggest that SM may influence th effect of EA analgesia,whichinvolves in both PT and extrapyramidal system (EPS).The PT may decreasethe effect of EA,but the EPS may increase the effect of EA.