Ohara P T
Department of Anatomy, University of California San Francisco 94143.
J Electron Microsc Tech. 1988 Nov;10(3):283-92. doi: 10.1002/jemt.1060100306.
This study describes the synaptic organization of the thalamic reticular nucleus (TRN) in the rat, cat, and monkey using electron microscopy combined with immunocytochemistry, degeneration, or horseradish peroxidase (HRP) tracing methods. Three morphological types of terminals are described in the TRN of the rat: a small terminal with densely packed spherical vesicles (D-terminal), which originates from the cortex; a large terminal with loosely packed spherical vesicles (L-terminal), which originates in the dorsal thalamus; and a terminal containing flattened synaptic vesicles (F-terminal) that is probably a TRN recurrent collateral. The cortical input to the TRN has been shown by double-labeling studies to terminate directly upon TRN projection neurons. Similar classes of terminals are found in the TRN of cat and monkey, but there is in addition a large terminal with spherical synaptic vesicles that is invaginated by dendritic spines. Also present in the cat and monkey, but not in the rat, are vesicle-containing dendrites and dendritic appendages. In the rat, degeneration experiments indicate that the terminals of TRN projection neurons in the dorsal thalamus are F-terminals. These terminals contain flattened synaptic vesicles and exhibit GABA immunoreactivity.
本研究运用电子显微镜结合免疫细胞化学、变性或辣根过氧化物酶（HRP）追踪法，描述了大鼠、猫和猴丘脑网状核（TRN）的突触组织。在大鼠的TRN中描述了三种形态类型的终末：一种小终末，含有紧密堆积的球形囊泡（D终末），起源于皮层；一种大终末，含有松散堆积的球形囊泡（L终末），起源于背侧丘脑；还有一种含有扁平突触囊泡的终末（F终末），可能是TRN的返回侧支。双重标记研究显示，皮层对TRN的输入直接终止于TRN投射神经元。在猫和猴的TRN中发现了类似类型的终末，但此外还有一种大终末，含有被树突棘内陷的球形突触囊泡。猫和猴中还存在含囊泡的树突和树突附属物，而大鼠中没有。在大鼠中，变性实验表明背侧丘脑中TRN投射神经元的终末是F终末。这些终末含有扁平突触囊泡，并表现出GABA免疫反应性。
