正常和病理状态下“关元”穴的中枢神经束路示踪研究及电针的影响

Observation on the Central Afferent Pathway of "Guanyuan"(CV 4) under Normal and Pathological States and the Influence of Electroacupuncture

目的:应用伪狂犬病毒(PRV)作为神经示踪剂研究正常和病理状态下"关元"穴针刺信号从穴位传递到神经中枢的通路,并观察电针对其影响。方法:将SD雌性大鼠随机分为正常组(NC)、正常加电针组(NC+EA)、去卵巢组(OVX)和去卵巢加电针组(OVX+EA)。OVX和OVX+EA组行双侧卵巢切除术,术后4周与NC和NC+EA组同时在"关元"穴注射10μl滴度为108plaque-formingunits(PFU)/ml的PRV。NC+EA和OVX+EA组在注射病毒后30min在"关元"穴给予电针处理(2Hz,2～3mA),每天1次,每次30min,连续3d。用免疫组化法观察PRV免疫阳性细胞在中枢神经系统的分布及数量。结果:1)4组大鼠的脊髓、脑干、下丘脑以及大脑皮层均可观察到PRV免疫阳性细胞,其主要分布为:脊髓腰、胸、颈段的腹侧和背侧角,脑干孤束核、巨细胞网状核、三叉神经脊束核、下橄榄核等,下丘脑室旁核、弓状核、腹内侧核、斜角带核、视前大细胞亚核等,以及皮层的纹状区等。2)在OVX组,与神经内分泌密切相关的核团中PRV免疫阳性细胞数量明显减少,如:隔内侧核、室旁核、弓状核、斜角带核(P<0.05);部分核团甚至无阳性表达,如:下丘脑视前大细胞亚核、腹内侧核(P<0.01)。OVX+EA组在相同核团内的阳性细胞数量与OVX组相比明显增加(P<0.05)。NC和NC+EA组相比差异无显著性意义(P>0.05)。结论:去卵巢后,机体功能发生异常,正常状态下的神经通路受到影响;针刺"关元"可促进原有神经结构的恢复。

Objective To investigate the afferent pathways of ＂Guanyuan＂ （CV 4） under normal and pathological states and to observe the effect of electroacupuncture （EA） on them. Methods Twenty-four female SD rats were randomly divided into normal control （NC）, NC＋ EA, ovariectomy （OVX） and OVX＋ EA groups, with 6 cases in each. Four weeks after OVX, Pseudorabies Virus （PRV, 10 μl liquid containing 108 plaque-forming units） was injected into CV4. Thirty minutes after PRV injection, EA （2 Hz, 2--3 mA） was applied to CV4 for 30 minutes, once daily for 3 days. Six hours after the third EA treatment, all the rats were perfused transcardially with 4% paraformaldehyde under anesthesia, followed by sampling the brain and spinal cord and cutting into sections （35 μm）. Immunohistochemical method （rabbit anti-rat beta-galactosidase） was used to display PRV immunoreactive （PRV-IR） positive neurons. Results 1 ） After injection of PRV, PRV-IR positive cells widely distributed in the spinal cord （cervical, thoracic and lumbar segments）, brain stem （nucleus of solitary tract, cuneate nucleus, gigantocellular reticular nucleus,nucleus of spinal tract of trigeminal nerve, nucleus raphe magnus, locus caeruleus, etc）, hypothalamus and cerebral cortex in each group. 2） After OVX, apparently fewer PRV-IR positive cells were found in some nuclei as medial septum nucleus （MSN）, arcuate nucleus （ARC）, diagonal band nucleus （DBN）, paraventricular nucleus （PVN） which have close relation with endocrine activity （P〈0.05） ; and rarely seen in ventromedial hypothalamus （VMH） and lateral preoptic area （LPO） （ P-〈0.01 ）. But in OVX＋EA group, PRV-IR positive cells in above regions or nuclei increased significantly （P〈0.05 or P〈0.01 ）. No obvious difference was found between NC and NC＋ EA groups in the number of PRV-IR positive cells （P〉0.05）. Conclusion Following OVX, PRV-IR positive cells in neuroendocrine-related nuclei of hypothalamus reduced significantly in number; EA of ＂Guanyuan＂ （CV 4） can promote the recovery of these neurons in above mentioned nuclei.