CELLULAR & MOLECULAR NEUROBIOLOGY: SYNAPSE FORMATION & MODULATION

我们用3D电子显微镜技术 烟碱受体簇附近的膜精细结构 先前被描述为在鸡睫状神经节上的“突触周” 神经元 受体由α 7亚基组成， 具有高亲和力的α-银环蛇毒素。 正在测试的假设是 受体簇是否在很大程度上 分布在压在细胞表面的假树突上 在补丁。 神经元既有新鲜分离的，也有整个神经节中的 将用HRP结合或生物素化标记 或者直接用高压电 EM或将首先通过共聚焦荧光显微镜检查， 定位受体簇，并通过EM对其进行检查，以确定相关的 精细结构 生物素化的银环蛇毒素将被定位在10 纳米胶体金。 该项目的工作正在进行中。 几本厚厚 HRP标记的睫状神经节细胞切片已经被检查 这表明这些神经元具有躯体棘， 上面有大量的银环蛇毒素 银环蛇毒素的模式 结合位点正在使用电子断层扫描进一步检查， 胶体金标记标本。 在断层重建中， 我们可以很容易地解决复杂的躯体棘缠结， 量化膜的多刺和非多刺区域上的标记。

We are using 3D electron microscopic techniques to examine membrane fine structure in the vicinity of nicotinic receptor clusters previously described as being "perisynaptic" on chick ciliary ganglion neurons. The receptors are composed of alpha 7 subunits and bind alpha-bungarotoxin with high affinity. The hypothesis being tested is whether the receptor clusters may in large part represent receptors distributed over pseudodendrites compressed against the cell surface in patches. Neurons both freshly dissociated and in whole ganglia will be labeled with either HRP conjugated or biotinylated alpha-bungarotoxin and either examined straightaway with high voltage EM or will be examined first by confocal fluorescence microscopy to locate receptor clusters and them examined by EM to identify related fine structure. The biotinylated bungarotoxin will be localized by 10 nm colloidal gold. Work on this project is underway. Several thick sections of HRP-labeled ciliary ganglion cells have been examined which indicated that these neurons possess somatic spines that are heavily labeled with bungarotoxin. The pattern of bungarotoxin binding sites is being examined further using electron tomography and colloidal gold labeled specimens. In the tomographic reconstructions, we can easily resolve the complex tangle of somatic spines as well as quantify the labeling over spiny and non-spiny regions of membrane.