Einstein G, Davis T L, Sterling P
J Comp Neurol. 1987 Jun 1;260(1):63-75. doi: 10.1002/cne.902600106.
The morphology of synapses in layer IV of the cat striate cortex was studied by electron microscope (EM) autoradiography of serial sections following injection of tritiated amino acids into the lateral geniculate nucleus. Of the terminals in the neuropil, 22% had 2 or more silver grains in 10 successive sections and were labeled at 8-80 times the background level. These terminals were considered to be specifically labeled and to be derived from the lateral geniculate. Two forms of geniculate synapse were observed. One had medium-size, round vesicles and a modest postsynaptic asymmetry (RA); the other had smaller, pleomorphic vesicles and hardly any postsynaptic opacity; that is, it appeared symmetrical (PS). The geniculate RA terminals were presynaptic to dendritic spines, fine processes, and cell bodies; the geniculate PS terminals were presynaptic to dendrites and cell bodies but not to spines. The possible sources of geniculate PS terminals are discussed.
通过向外侧膝状体核注射氚标记氨基酸后对连续切片进行电子显微镜（EM）放射自显影，研究了猫纹状皮层IV层突触的形态。在神经毡中的终末中，22%在连续10个切片中有2个或更多银颗粒，标记水平为背景水平的8 - 80倍。这些终末被认为是特异性标记的，并且来自外侧膝状体。观察到两种形式的膝状体突触。一种具有中等大小的圆形囊泡和适度的突触后不对称性（RA）；另一种具有较小的、多形性囊泡且几乎没有突触后不透明度；也就是说，它看起来是对称的（PS）。膝状体RA终末位于树突棘、细突起和细胞体的突触前；膝状体PS终末位于树突和细胞体的突触前，但不位于棘的突触前。讨论了膝状体PS终末的可能来源。
