Carlton S M, Lamotte C C, Honda C N, Surmeier D J, Delanerolle N, Willis W D
Department of Anatomy, University of Texas Medical Branch, Galveston 77550-2772.
J Comp Neurol. 1989 Mar 22;281(4):555-66. doi: 10.1002/cne.902810406.
The morphology and frequency of axosomatic contacts on three functionally identified primate spinothalamic tract (STT) cells were analyzed at the electron microscopic level. The STT cells analyzed were wide-dynamic-range neurons responsive to activation of low- and high-threshold cutaneous afferents innervating the foot. The somas were located in the lateral border of lamina V; the dendritic trees were oriented dorsally and were very extensive. Numerous spinelike appendages were observed emanating from two of the cell bodies. Terminal types contacting the cell bodies were categorized at several different layers through each neuron. Six morphologically different terminal types were established following analysis of serial sections. Profiles classified as round (R) terminals containing round clear vesicles and zero or one dense-core vesicle made up over 50% of the total population in contact with the STT somas. Profiles containing round clear vesicles and two to four small-diameter dense-core vesicles (D1 category) made up approximately 10% of the population in contact with each soma. Flat (F) terminals with oblong or flattened clear vesicles made up approximately 8% of the population. The remaining three categories (D2, L1, and L2) distinguished by the number and size of the dense-core vesicles made up a small percentage of the total population in contact with the cell bodies. The distribution of terminal types on the soma proper versus somatic spines was also determined for one cell. The proportions of the six terminal types contacting the soma of these cells were very similar, although the physiological characteristics of each cell were different. However, the relative proportions of terminal types on these three lamina V STT cell bodies were different from those previously reported contacting somata in lamina V, suggesting that there may be a unique innervation of STT cells that differentiates them from other cell types in lamina V.
在电子显微镜水平上分析了三只功能已确定的灵长类动物脊髓丘脑束（STT）细胞上轴体突触的形态和频率。所分析的STT细胞是对支配足部的低阈值和高阈值皮肤传入神经激活有反应的广动力范围神经元。细胞体位于V层外侧边缘；树突伸向背侧且非常广泛。在两个细胞体上观察到许多棘状附属物。通过每个神经元在几个不同层面上对与细胞体接触的终末类型进行了分类。对连续切片进行分析后确定了六种形态不同的终末类型。被归类为圆形（R）终末，含有圆形清亮小泡和零个或一个致密核心小泡，在与STT细胞体接触的总数中占比超过50%。含有圆形清亮小泡和两到四个小直径致密核心小泡（D1类）的终末在与每个细胞体接触的总数中约占10%。具有椭圆形或扁平清亮小泡的扁平（F）终末约占总数的8%。其余三类（D2、L1和L2）以致密核心小泡的数量和大小区分，在与细胞体接触的总数中占比很小。还确定了一个细胞在细胞体本身与体细胞棘上终末类型的分布。尽管每个细胞的生理特征不同，但与这些细胞体接触的六种终末类型的比例非常相似。然而，这三个V层STT细胞体上终末类型的相对比例与先前报道的与V层细胞体接触的比例不同，这表明可能存在STT细胞独特的神经支配，使其与V层中的其他细胞类型有所区别。
