DiFiglia M, Carey J
J Comp Neurol. 1986 Feb 1;244(1):36-52. doi: 10.1002/cne.902440104.
Large neurons in the monkey neostriatum were examined in the electron microscope in tissue treated with the rapid-Golgi impregnation method followed by the gold-toning procedure. Two types of large neurons were investigated: an aspiny neuron (aspiny type II; N = 5) with numerous varicose dendrites and a spiny cell (spiny type II; N = 1) with few sparsely spined dendrites. The large aspiny neurons had variably shaped somata, an eccentric highly invaginated nucleus, and a cytoplasm rich in organelles. Mitochondria were distributed unevenly in dendrites and were localized primarily in varicosities. Some mitochondria exhibited dense bodies 80-300 nm in size. Most synapses (84%) onto large aspiny neurons occurred 20 micron or more from the cell body and contacted dendritic varicosities (63%). A smaller proportion of boutons (21%) contacted constricted portions of varicose segments. A low incidence of synaptic boutons was observed on smooth primary and secondary dendrites (11%), cell bodies (3%), and branch points (2%). Seven percent of the axons that synapsed with large aspiny neurons also contacted nearby dendrites or spines of medium-sized spiny neurons. At least eight morphologically distinct types of axons making synapses with large aspiny neurons were identified and included both symmetric and asymmetric types. The large spiny neuron was different from the large aspiny neuron in its subcellular characteristics. Synapses were found on all portions of the cell, including the axon initial segment, but fewer types of axonal inputs were identified. These findings confirm that the two types of large neurons identified in Golgi impregnations of the primate neostriatum are also different at the ultrastructural level, both in their cytological features and in their synaptic organization. The large aspiny neuron integrates synaptic inputs that innervate a relatively large area of caudate neuropil and appear to arise from a variety of extrinsic and intrinsic sources. The high density of synaptic inputs to dendritic varicosities suggests that they have an important functional role.
采用快速高尔基浸染法并结合金染色程序处理组织后，利用电子显微镜对猴新纹状体中的大神经元进行了研究。研究了两种类型的大神经元：一种是无棘神经元（无棘II型；N = 5），其树突有许多曲张；另一种是有棘细胞（有棘II型；N = 1），其树突少且有稀疏的棘。大的无棘神经元胞体形状各异，核偏心且高度内陷，细胞质富含细胞器。线粒体在树突中分布不均，主要集中在曲张部位。一些线粒体呈现出大小为80 - 300纳米的致密体。大多数与大无棘神经元形成的突触（84%）发生在距细胞体20微米或更远的地方，并与树突曲张部位接触（63%）。较小比例的轴突终扣（21%）与曲张段的收缩部位接触。在光滑的一级和二级树突（11%）、胞体（3%）和分支点（2%）上观察到突触终扣的发生率较低。与大无棘神经元形成突触的轴突中有7%也与附近的中棘神经元的树突或棘接触。至少鉴定出了八种与大无棘神经元形成突触的形态学上不同的轴突类型，包括对称型和不对称型。大的有棘神经元在亚细胞特征上与大无棘神经元不同。在细胞的所有部位包括轴突起始段都发现了突触，但鉴定出轴突输入的类型较少。这些发现证实，在灵长类新纹状体的高尔基浸染中鉴定出的两种类型的大神经元在超微结构水平上，无论是在细胞学特征还是在突触组织方面也都不同。大的无棘神经元整合来自相对较大面积尾状神经毡的突触输入，这些输入似乎来自多种外在和内在来源。树突曲张部位的突触输入高密度表明它们具有重要的功能作用。
