針刺對脊髓可塑性的影響之電子顯微鏡定量研究

The Effect of Acupuncture on Plasticity of Cats Spinal Cord-Quantitative Electron Microscopic Study

哺乳類中樞神經系統的脊髓受損傷後，具有可塑性變化的事實，已得到不少學者的證實。臨床上，中國傳統醫學的鍼刺療法是當前治療脊髓損傷性疾患的手段之一。本文採用貓雙側後肢備用根模型（切斷L1~L5，L7~S2脊神經背根，保留L6背根備用）研究鍼刺對脊髓可塑性有無促進作用－即鍼刺一側後肢穴位，比較脊髓兩侧Ⅱ板層突觸性終末的形態，數量差異。選擇位於L6脊神經分佈範圍內，並與治療截癱麻痺等脊髓病症有關的足三里與懸鐘，伏兔與三陰交兩組穴位，以G6805型電鍼儀鍼刺兩個療程，每療程10天。手術後四周灌注固定，取材，製做L5，L6後角Ⅱ板層超薄大切片，在抽樣的電子顯微鏡照片上進行兩類終未的形態計量研究。發現鍼刺側背根來源的複合終末（2.22±0.11個／100μm^2）比未鍼刺側（1.68±0.12個／100μm^2）增加三分之一，且在備用根頭側節段(L5)複合終未的增幅(70%)大於備用根L6節段的增幅(20%)；而背根來源簡單終末的數量卻沒有顯著的變化。表明鍼刺能促進同側備用根神經纖維的側支出芽與突觸重建，以代償損傷後丟失的背根終末。

There are considerable evidences for lesion induced plasticity in the mammalian spinal cord, especially in cat. Many reports showed that recovery from spinal cord injury may be improved by traditional Chinese medicine-acupuncture. However, up to date, there is no morphological evidence to support the clinical results. In order to detect the effect of acupuncture on plasticity of injured spinal cord, 5 adult male cats were subjected to section of the bilateral hind limb dorsal root (L1-S2), except roots of both L6. Two days after operation, the animals were acupunctured on one side daily at two pairs of points alternatively, for ten days per course. The pairs of points, which locate in the innervation area of L6 and relate to treatment of spinal injury, are Zusanli and Xuanzhong, Sanyinjiao and Futu. The unacupunctured side was used as control. After two courses of acupuncture (4 wks), the cats were perfused and prepared for electron microscopy. Neuropil of whole lamina Ⅱ was examined under transmissional electron microscope and photoed systematically at a magnification of 7000X. The dorsal root terminals were identified and calculated. On acupuncture side, the number of complex terminal (large and making more than one synaptic contacts) increased (2.22± 0.11/100 μm^2) significantly (32%, P＜0.01) by comparing with unacupuncture side (1.68±0.12/100 μm^2). The increasing of complex terminal in L5 (70%) was higher than spared root L6 (20%). There was no change in the number of simple terminal (small and making only one synaptic contact) from descending and intraspinal axons. We suggest that acupuncture may promote the ipsilateral, but not contralateral, spared L6 root to sprout and establish new contacts with postsynaptic profiles for compensating the lost complex terminals.