IMMUNOREACTIVE GLUTAMIC-ACID DECARBOXYLASE IN THE TRIGEMINAL NUCLEUS CAUDALIS OF THE CAT - A LIGHT-MICROSCOPIC AND ELECTRON-MICROSCOPIC ANALYSIS
IMMUNOREACTIVE GLUTAMIC-ACID DECARBOXYLASE IN THE TRIGEMINAL NUCLEUS CAUDALIS OF THE CAT - A LIGHT-MICROSCOPIC AND ELECTRON-MICROSCOPIC ANALYSIS
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DOI：
10.3109/07367228609144599
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发表时间：
1986-01-01
期刊：
影响因子：
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通讯作者：
OERTEL, W
中科院分区：
文献类型：
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作者：
BASBAUM, AI;GLAZER, EJ;OERTEL, W
该研究使用了针对谷氨酸脱羧酶（GAD）的抗血清，谷氨酸脱羧酶是γ-谷氨酰胺的生物合成酶。氨基丁酸（GABA），检查光和电子显微镜分布的假定GABA能突触的猫脊髓后角，三叉神经核尾侧的髓质同系物。在光镜水平，免疫反应终末集中在背角浅层，板层I和II。秋水仙素一般不能显示胞体的分布。然而，在两个成功的情况下，大多数标记的细胞被发现在大细胞层，腹侧的胶状质，一个区域，具有较低的免疫反应性终端的密度。其他标记神经元散在分布于I、II层。在电镜水平上发现了多种突触排列。这些来自两种类型的标记终端。一个包含小的圆形囊泡和大的致密核心囊泡。第二个包含小的圆形和多形性囊泡。一些免疫反应阳性的GAD终末含有一些扁平的囊泡。标记终端主要形成轴树突触，通过对称的接触。还观察到几种轴轴排列。在大多数情况下，GAD终端（其中不包含致密核心囊泡）是突触前到另一个囊泡含有配置文件，包括扇贝中央终端认为来自初级传入。另一个人口标记的GAD终端被发现突触后未标记的囊泡包含的配置文件，包括中央终端。这些数据表明，抑制性GABA能控制三叉神经尾侧核涉及突触前和突触后机制，并可能介导通过直接接触到上行投射神经元，以及通过突触接触到伤害性初级传入纤维。
This study used antisera directed against glutamic acid decarboxylase (GAD), the biosynthetic enzyme for .gamma.-aminobutyric acid (GABA), to examine the light- and electron-microscopic distribution of presumed GABA-ergic synapses in the medullary homologue of the cat spinal dorsal horn, the trigeminal nucleus caudalis. At the light-microscopic level, immunoreactive terminals were concentrated in the superficial dorsal horn, laminae I and II. Colchicine was generally ineffective in revealing the distribution of cell bodies. However, in two successful cases, the majority of labeled cells were found in the magnocellular layer, ventral to the substantia gelatinosa, a region that had a lower density of immunoreactive terminals. Other labeled neurons were scattered in laminae I and II. A variety of synaptic arrangements were found at the electron-microscopic level. These derived from two types of labeled terminals. One contained both small round vesicles and large dense-cored vesicles. The second contained small round and pleomorphic vesicles. Some immunoreactive GAD terminals contained a few flat vesicles. Labeled terminals predominantly formed axodendritic synapses, via symmetrical contacts. Several axoaxonic arrangements were also observed. In most cases, the GAD terminal (which did not contain dense-cored vesicles) was presynaptic to another vesicle-containing profile, including the scalloped central terminal thought to derive from primary afferents. Another population of labeled GAD terminals was found postsynaptic to unlabeled vesicle-containing profiles, including central terminals. These data indicate that inhibitory GABA-ergic controls in the trigeminal nucleus caudalis involve both presynaptic and postsynaptic mechanisms and are probably mediated via direct contacts onto ascending projection neurons, as well as via synaptic contacts onto nociceptive primary afferent fibers.