Glutamatergic connections of the auditory midbrain: selective uptake and axonal transport of D-[3H]aspartate.
Glutamatergic connections of the auditory midbrain: selective uptake and axonal transport of D-[3H]aspartate.
复制标题
DOI：
10.1002/(sici)1096-9861(19960916)373:2
复制
发表时间：
1996-09
期刊：
影响因子：
--
通讯作者：
R. L. Marie
中科院分区：
文献类型：
--
作者：
R. L. Marie
D-[3 H]天冬氨酸被用来确定潜在的毛丝鼠下丘（IC）的突触能连接。D-[3 H]天冬氨酸的高亲和力摄取被认为是谷氨酸能突触的选择性标记物，并且从这种注射中逆行标记的神经元被认为使用谷氨酸或密切相关的化合物作为递质。注射D-[3 H]天冬氨酸表明，在IC的神经末梢主要来自内在的连接，相反的IC，颞叶皮层，鞍状核，外侧丘系核的第5层。神经元产生到IC的主要感觉（丘系）投射，即，来自耳蜗核、上级橄榄核的突触和来自外侧丘系核的大多数投射在这些实验中没有标记，表明它们的突触不识别D-[3 H]天冬氨酸作为合适的底物，并且可能使用抑制性或其他兴奋性递质。IC注射后，纤维和弥漫性标记被发现同侧的内侧膝状体，上级丘，和背外侧脑桥核，对侧的IC，和双侧的上级橄榄和耳蜗核。这种标记是由于顺行运输D-[3 H]天冬氨酸标记IC神经元的传出侧支内，这表明许多IC的传出投射也可能是神经递质。这种解释在单独的实验中得到了证实，其中D-[3 H]天冬氨酸，注射在内侧膝状体中，逆行标记IC中的神经元以及颞叶皮层的第6层。最后，中脑三叉神经核和束在某些情况下被标记，并可能具有局部的神经元联系。© 1996 Wiley-Liss公司。
D-[3H]aspartate was used to identify potential glutamatergic connections of the chinchilla inferior colliculus (IC). High-affinity uptake of D-[3H]aspartate is considered a selective marker for glutamatergic synapses, and neurons retrogradely labeled from such injections are believed to use glutamate, or a closely related compound, as a transmitter. Injections of D-[3H]aspartate suggest that glutamatergic endings in the IC arise primarily from intrinsic connections, the opposite IC, layer 5 of temporal cortex, nucleus sagulum, and lateral lemniscal nuclei. Neurons giving rise to the principal sensory (lemniscal) projections to the IC, i.e., those from the cochlear nuclei, superior olive, and the majority of projections from the lateral lemniscal nuclei, did not label in these experiments, indicating that their synapses do not recognize D-[3H]aspartate as a suitable substrate and may use inhibitory or other excitatory transmitters. After IC injections, fiber and diffuse labeling was found ipsilaterally in the medial geniculate body, superior colliculus, and dorsolateral pontine nuclei, contralaterally in the IC, and bilaterally in the superior olive and cochlear nuclei. Such labeling was attributed to anterograde transport of D-[3H]aspartate within the efferent collaterals of labeled IC neurons, suggesting that many of the IC's efferent projections may also be glutamatergic. This interpretation was confirmed in separate experiments in which D-[3H]aspartate, injected in the medial geniculate body, retrogradely labeled neurons in the IC as well as in layer 6 of temporal cortex. Finally, the mesencephalic trigeminal nucleus and tract labeled in some cases and may have local glutamatergic connections. © 1996 Wiley-Liss, Inc.