• 作者： 劉江川; 王順德; 劉英英
• 作者服務機構： 國防醫學院生物型態學系
• 中文摘要： 利用光學及電子顯微鏡比較觀察成年哺乳動物中樞神經系統受損後，其功能恢復的組織機理。貓經單側腰薦背根切除後，飼養八個月，以便退化物從脊髓中的實驗側完全清除，再經超微技術處理之。顯微觀測顯示，實驗側背角I-III層整個型態有些許萎縮及變形，超微結構定量分析，結構諸如細胞體和樹突，以及軸突終末幾乎維持原數沒有多大的改變。可是膠質纖維就有很明顯的增加，而有髓鞘纖維相對的減少，最引人的乃是一種無髓鞘小纖維（0.05～2μ）顯著的增加，聚集成束，常隨附在膠質纖維的周圍。該無髓鞘小纖維，較正常者為細小，但成束的數目則較大。其亦含有微細小管、軸絲及傳遞小泡等。這些無髓鞘小纖維一經證實為小軸突，則本實驗的結果將提供一個滿意的證明。因背根的被切除，可導引新軸突的生成，此乃功能恢復的主因。
• 英文摘要： Comparative ultrastructural studies were undertaken using light and electron microscopy in an at-tempt to clarify the morphological basis for functional recovery in the adult mammalian CNS after dener-vation. Unilateral lumbosacral deafferentation was performed on adult cats allowing an eight month pos-toperative recovery period to ensure the complete removal of degeneration debris from the deafferentedareas. Microscopic examination of Laminae I-III of the dorsal horn revealed shrinkage and distortion in allthree laminae on the deafferented side. Photomicrographic analysis of thin sections from each of thelaminae revealed that, while the relative areas occupied by postsynaptic components (cell bodies, dendrites)and the general morphology of vesicle terminals remained essentially unchanged, there was a marked in-crease in glial cytoplasm and a corresponding, decrease in myelinated axons in all three laminae on thedeafferented side. Most striking was the substantial increase in the number of small (0.05-2μ) profiles onthe deafferented side. These small profiles are typically grouped in bundles which are often found associat-ed with glial cytoplasm. EM comparison showed that, while the individual profiles on the deafferented sidewere smaller in diameter, the individual bundles were much larger. These small profiles contain micro-tubules, filaments, and some vesicular materials. If they can eventually be identified as axon profiles, theseresults provide support for the contention that axonal growth occurs in response to deafferentation andmay play a major role in functional recovery.
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