IDENTIFICATION OF DORSAL ROOT SYNAPTIC TERMINALS ON MONKEY VENTRAL HORN CELLS BY ELECTRON-MICROSCOPIC AUTO-RADIOGRAPHY
IDENTIFICATION OF DORSAL ROOT SYNAPTIC TERMINALS ON MONKEY VENTRAL HORN CELLS BY ELECTRON-MICROSCOPIC AUTO-RADIOGRAPHY
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DOI：
10.1007/bf01175558
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发表时间：
1979-01-01
期刊：
影响因子：
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通讯作者：
RALSTON, DD
中科院分区：
文献类型：
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作者：
RALSTON, HJ;RALSTON, DD
用光学显微镜和电子显微镜放射自显影技术研究了猕猴[Macaca mulatta]脊髓背根纤维向运动核的投射。光镜下可见腹角初级传入纤维的标记非常稀疏。覆盖在放射源上的银颗粒经常聚集成小群，通常靠近树枝状轮廓。在EM下，有髓轴突和含有圆形突触小泡的几个大突触轮廓被大量的Ag颗粒覆盖。这些标记的轮廓使突触与直径1-3微米的树突接触。标记的轮廓不接触腹角神经元的胞体或大的近端树突。含有扁平小泡的小突触轮廓与大的标记终末发生突触前反应，提示这些轴突可能参与了对初级传入纤维的突触前抑制。目前的发现与以前发表的生理学和解剖学研究的关系进行了讨论。
The projection of dorsal root fibers to the motor nucleus of the macaque monkey [Macaca mulatta] spinal cord was examined utilizing light microscopy (LM) and EM autoradiography. LM demonstrates a very sparse labeling of primary afferent fibers in the ventral horn. Ag grains overlying radioactive sources are frequently clustered into small groups, often adjacent to dendritic profiles. Under the EM, myelinated axons and a few large synaptic profiles containing rounded synaptic vesicles were overlain by numerous Ag grains. These labeled profiles made synaptic contact with dendrites 1-3 .mu.m in diameter. The labeled profiles did not contact cell bodies or large proximal dendrites of ventral horn neurons. Small synaptic profiles containing flattened vesicles were presynaptic to the large labeled terminals and it is suggested that these axoaxonal synapses may mediate presynaptic inhibition of the primary afferent fibers. The relationship of the present findings to previously published physiological and anatomical studies is discussed.