Ehrlich D, Keyser K, Manthorpe M, Varon S, Karten H J
Department of Anatomy, Monash University, Clayton, Victoria, Australia.
Neuroscience. 1990;36(3):699-723. doi: 10.1016/0306-4522(90)90013-t.
The time course of degeneration of chick retinal ganglion cells was examined with Nissl stains and immunohistochemical methods for detection of substance P-like immunoreactive and nicotinic acetylcholine receptor immunoreactive neurons. Small lesions were made in the retinae, adjacent to the optic nerve head, and were subsequently sectioned parallel to the vitreal surface, permitting direct comparison of normal and axotomized retinal ganglion cells distal to the site of axon damage. At four and six days after surgery, a large number of degenerating cells with clear cytoplasm and pyknotic nuclei were seen. After eight, 10 and 14 days, many retinal ganglion cells displayed a chromatolytic response with dispersed Nissl granules, eccentric nuclei and the cells appeared crenulated. The number of apparently normal neurons in the ganglion cell layer in the axotomized region was reduced by about 50% six days following surgery, by about 70% on the 10th day and by about 75% on the 17th day. The remaining neurons in the ganglion cell layer were identified as displaced amacrine cells. From day 2 onwards, increased numbers of glial cells were present in the optic fibre, ganglion cell and inner plexiform layers. Many glial cells were enlarged and displayed extensive cytoplasmic processes, while others showed mitotic activity. Somata and proximal dendrites of retinal ganglion cells were intensely stained for substance P-like immunoreactivity at two and four days following surgery. At six, eight and 10 days, staining intensity was markedly reduced though still evident and at 14 and 17 days, substance P-like immunoreactivity had virtually disappeared. The persistence of limited substance P-like immunoreactive ganglion cells 10 days after surgery indicates that these cells have a relatively protracted response to axotomy. Nicotinic acetylcholine receptor-like immunoreactivity in the ganglion cells at two and four days following axotomy was substantially reduced. The majority of faintly stained nicotinic acetylcholine receptor-like immunoreactive ganglion cells, as visualized in counterstained sections, did not exhibit pyknosis in the immediate period following axotomy. Double label studies demonstrated that substance P-like immunoreactive ganglion cells were distinct from the nicotinic acetylcholine receptor-like immunoreactive ganglion cells. In a second set of experiments, nerve growth factor was then placed into the vitreous humor following intra-retinal axotomy. The somata, dendrites and proximal axons of lesioned substance P-like immunoreactive ganglion cells in these retinae were more intensely stained for a longer period of time and appeared more robust than cells from untreated retinae.(ABSTRACT TRUNCATED AT 400 WORDS)
采用尼氏染色法以及免疫组织化学方法检测P物质样免疫反应性神经元和烟碱型乙酰胆碱受体免疫反应性神经元，以此研究雏鸡视网膜神经节细胞的变性时间进程。在紧邻视神经乳头的视网膜处制造小损伤，随后将其平行于玻璃体表面切片，从而能够直接比较轴突损伤部位远端正常和轴突切断的视网膜神经节细胞。术后4天和6天，可见大量细胞质清晰、细胞核固缩的变性细胞。术后8天、10天和14天，许多视网膜神经节细胞呈现染色质溶解反应，尼氏颗粒分散、细胞核偏心，细胞呈锯齿状。术后6天，轴突切断区域神经节细胞层中明显正常的神经元数量减少约50%，第10天减少约70%，第17天减少约75%。神经节细胞层中剩余的神经元被鉴定为移位无长突细胞。从第2天起，视神经纤维层、神经节细胞层和内网状层中的胶质细胞数量增加。许多胶质细胞增大并显示出广泛的细胞质突起，而其他细胞则表现出有丝分裂活性。术后2天和4天，视网膜神经节细胞的胞体和近端树突对P物质样免疫反应性染色强烈。在6天、8天和10天，染色强度明显降低但仍可见，在14天和17天，P物质样免疫反应性几乎消失。术后10天仍有有限数量的P物质样免疫反应性神经节细胞，这表明这些细胞对轴突切断有相对持久的反应。轴突切断后2天和4天，神经节细胞中烟碱型乙酰胆碱受体样免疫反应性显著降低。在复染切片中可见，大多数轻度染色的烟碱型乙酰胆碱受体样免疫反应性神经节细胞在轴突切断后的即刻并未出现核固缩。双重标记研究表明，P物质样免疫反应性神经节细胞与烟碱型乙酰胆碱受体样免疫反应性神经节细胞不同。在第二组实验中，视网膜内轴突切断后将神经生长因子注入玻璃体内。这些视网膜中受损的P物质样免疫反应性神经节细胞的胞体、树突和近端轴突在更长时间内染色更强，并且比未处理视网膜中的细胞看起来更健壮。（摘要截断于400字）
