Burmeister D W, Chen M, Bailey C H, Goldberg D J
Department of Pharmacology, Columbia University College of Physicians and Surgeons, NY.
J Neurocytol. 1988 Dec;17(6):783-95. doi: 10.1007/BF01216706.
The morphology of growth cones from identified neurons of Aplysia californica was analysed both with video-enhanced contrast differential-interference contrast (VEC-DIC) microscopy, and through serial electron microscopic reconstructions of the same growth cones. The largest structures seen in the living growth cones, the large irregular refractile bodies (LIRBs), were shown in electron micrographs to be unique structures, composed predominantly of dense-core vesicles but including mitochondria and smooth membrane profiles. The LIRBs were stratified in the growth cones, occurring predominantly in sections distant from the substrate and relatively devoid of microtubules. VEC-DIC observations showed that LIRBs formed in the peripheral regions of the organelle-rich central growth cone, and grew in size through fusion with other LIRBs, accumulating into a large central mass in more proximal regions. The distribution of microtubules and LIRBs and the movements of LIRB suggest that there is an overall circulatory pattern in the growth cones, with the delivery of new vesicles occurring at distal areas close to the substrate, and the accumulation and retrograde processing of organelles occurring in more proximal areas away from adhesive contacts.
利用视频增强对比微分干涉对比（VEC-DIC）显微镜以及对相同生长锥进行连续电子显微镜重建，分析了加州海兔已鉴定神经元生长锥的形态。在活体生长锥中观察到的最大结构，即大型不规则折射体（LIRBs），在电子显微镜照片中显示为独特结构，主要由致密核心囊泡组成，但也包括线粒体和光滑膜轮廓。LIRBs在生长锥中呈分层分布，主要出现在远离底物且微管相对较少的区域。VEC-DIC观察表明，LIRBs在富含细胞器的中央生长锥的周边区域形成，并通过与其他LIRBs融合而增大尺寸，在更靠近近端的区域聚集成一个大的中央团块。微管和LIRBs的分布以及LIRB的运动表明，生长锥中存在一种整体循环模式，新囊泡在靠近底物的远端区域递送，而细胞器在远离黏附接触的更靠近近端的区域积累和进行逆行处理。
