摘要
Objective To observe the effect of acupuncture stimulation of the sacral segment on the excitability of the cerebral cortex and the activity of the urinary bladder and the involvement of the cholinergic neurons in the laterodorsal tegmental （LDT） nucleus of the brainstem in acupuncture-induced electroencephalogram （EEG） changes. Methods A total of 109 SD rats were used in the present study. Under anesthesia （urethane）, a pair of stainless steel electrodes was separately implanted into the frontal and parietal bony sutures to record EEG. Glass microelectrodes were used to record extracellular discharges of single neuron of the LDT nucleus in the brainstem. Urinary bladder pressure was recorded through a catheter inserted in the bladder and the contraction was induced by infusion of normal saline. A filiform acupuncture needle was inserted into the sacral segment Ecorresponding to Zhongliao （中髎BL 33）] and rotated manually for 1 min. Results In 27 rats whose bladder was full of normal saline, acupuncture stimulation of the sacral region suppressed the contraction activity of the bladder, the fast EEG with lower amplitude and higher frequency tuned into slow EEG with higher amplitude and lower frequency in 6 cases （22.2%）. The inhibitory effect occurred from 45 s to 12 min after acupuncture manipulation. In 82 rats whose bladder was empty, acupuncture stimulation caused the fast EEG to turn into slow EEG in 71 cases （86.6%）. Simultaneously, LDT cholinergic neurons reduced their firing rates from （2.9±1.5） Hz to （1.2±0.6） Hz （n = 12, P〈0.05）, and the reduction of LDT neuronal discharge was earlier in time than the change of EEG. Conclusion Acupuncture stimulation of the sacral region can lower the excitability of the cerebral cortex and suppress bladder activity, which is closely associated with its resultant inhibitory effect on the electrical activity of LDT cholinergic neurons.
目的:探讨针刺对大脑皮层兴奋性和膀胱功能的影响及其之间的相互关系,探讨脑干背外侧被盖区(LDT)胆碱能神经元在其中的作用。方法:将SD大鼠109只,乌拉坦麻醉,采用立体定位法,在额骨和顶骨上植入皮层电极进行脑电图(EEG)记录,通过玻璃微电极记录单个神经细胞的放电活动。用导管插入膀胱并用微量注射泵向内注入生理盐水,使膀胱收缩并记录其活动。以直径为0.35mm毫针手针刺激大鼠脊髓骶部第2、3节段旁开0.5cm处1min,深度3～4mm。结果:在膀胱充盈的情况下,当EEG表现为低幅度高频率的快波时,给予脊髓骶段手针刺激,膀胱活动受到抑制,与此同时EEG转变为高幅度低频率慢波的比例为6/27(22.2%),抑制效应开始于针刺后45s至12min。在膀胱空虚的情况下,针刺引起EEG转变为高幅度低频率慢波的比例为71/82(86.6%)。针刺引起LDT内的胆碱能神经元放电频率由(2.9±1.5)Hz下降到(1.2±0.6)Hz(n=12,P<0.05,t-test),神经元放电活动的下降提前于EEG高幅度低频率的慢波的出现。结论:针刺脊髓骶段能降低大鼠大脑皮层的兴奋状态,并抑制膀胱活动,这种变化与针刺抑制了LDT胆碱能神经元的活动密切相关。
