Vidnyanszky Z, Gorcs T J, Negyessy L, Borostyankio Z, Knopfel T, Hamori J
Laboratory of Neurobiology, 1st Department of Anatomy, Smmelweis University Medical School, Tuzolto u. 58, 1094 Budapest, Hungary.
Eur J Neurosci. 1996 Jun;8(6):1061-71. doi: 10.1111/j.1460-9568.1996.tb01273.x.
Pre-embedding immunogold histochemistry was combined with Phaseolus vulgaris leucoagglutinin anterograde tract tracing in order to analyse the relationship between the subcellular localization of the GluR1a metabotropic glutamate receptors and the distribution of corticothalamic synapses in the dorsal lateral geniculate nucleus (dLGN) and the lateral posterior nucleus (LP) of the rat. The injection of the tracer into area 17 labelled two types of corticothalamic terminals: (i) the small boutons constituting the majority of the labelled fibres which form asymmetrical synapses both in the dLGN and LP; and (ii) the giant terminals typically participating in glomerulus-like synaptic arrangements and found exclusively in the lateral posterior nucleus. The small corticothalamic terminals often established synapses with mGluR1a-immunopositive dendrites, with immunometal particles concentrated at the periphery of their postsynaptic membranes. In contrast, the synapses formed by giant boutons in the lateral posterior nucleus were always mGluR1a-immunonegative. We conclude that the corticothalamic fibres forming the small synaptic terminals are the most likely candidates for the postulated mGluR-mediated modulation of visual information flow by corticothalamic feedback mechanisms.
将包埋前免疫金组织化学与菜豆白细胞凝集素顺行束路追踪相结合，以分析代谢型谷氨酸受体GluR1a的亚细胞定位与大鼠背侧外侧膝状体核（dLGN）和外侧后核（LP）中皮质丘脑突触分布之间的关系。将示踪剂注射到17区标记了两种类型的皮质丘脑终末：（i）构成大部分标记纤维的小终扣，其在dLGN和LP中均形成不对称突触；（ii）巨大终末，通常参与肾小球样突触排列，且仅见于外侧后核。小的皮质丘脑终末常与mGluR1a免疫阳性树突形成突触，免疫金属颗粒集中在其突触后膜周边。相反，外侧后核中由巨大终扣形成的突触总是mGluR1a免疫阴性。我们得出结论，形成小突触终末的皮质丘脑纤维最有可能是通过皮质丘脑反馈机制对视觉信息流进行推测的mGluR介导调节的候选者。
