DEVELOPMENT OF ACETYLCHOLINESTERASE-POSITIVE THALAMIC AND BASAL FOREBRAIN AFFERENTS TO EMBRYONIC RAT NEOCORTEX
DEVELOPMENT OF ACETYLCHOLINESTERASE-POSITIVE THALAMIC AND BASAL FOREBRAIN AFFERENTS TO EMBRYONIC RAT NEOCORTEX
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DOI：
10.1007/bf00231974
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发表时间：
1995-06-01
影响因子：
2
通讯作者：
OLEARY, DDM
中科院分区：
文献类型：
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作者：
DECARLOS, JA;SCHLAGGAR, BL;OLEARY, DDM
通过结合顺行和逆行轴突追踪与乙酰胆碱酯酶组织化学，我们证明了来源的乙酰胆碱酯酶阳性传入胚胎新皮层，他们使用的途径，他们到达皮层的时间，和他们的最初入侵的皮质板。乙酰胆碱酯酶（AChE）是由两个群体的皮质传入：AChE是永久存在于基底前脑纤维，并已被报道为短暂定位在主要的感觉丘脑核的轴突在出生后的头几个星期开始在第一周的中间。我们首先检测乙酰胆碱酯酶阳性传入组织化学在新皮层胚胎第十七天（E17），并确定它们产生的主要感觉丘脑核。乙酰胆碱酯酶组织化学标记的整个长度的发展丘脑皮质轴突，包括他们的生长锥和分支。这些AChE阳性传入神经通过内囊进入新皮质，并采取以基板层为中心的皮质内通路。一旦这些轴突被检测到，一些已经开始延伸乙酰胆碱酯酶阳性侧支表面向皮质板。到E19时，少数侧枝进入皮质板的深部，到E21时，除了最浅的未分化部分外，其他部分都已密集侵入。来自基底前脑结构的AChE阳性传入通过三条途径到达新皮层：外囊、内囊和扣带束。在基底前脑成分中，只有无名质和Meynert基底核通过内囊到达皮层。来自这两个来源的传入在E18时到达新皮层，但在这个年龄段的AChE阳性传入的总人口中是非常小的组成部分。来自基底前脑其他成分的传入神经直到几天后才到达新皮层。乙酰胆碱酯酶表达的空间和时间模式在开发丘脑皮层轴突表明，它是有用的描绘他们的神经支配的初级感觉区的胚胎新皮层，并建议，乙酰胆碱酯酶可能在轴突延伸和皮层分化的功能。
By combining anterograde and retrograde axonal tracing with AChE histochemistry, we demonstrate the sources of AChE-positive afferents to embryonic neocortex, the pathways they use, their time of arrival into cortex, and their initial invasion of the cortical plate. Acetylcholinesterase (AChE) is expressed by two populations of cortical afferents: AChE is permanently present in basal forebrain fibers and has been reported to be transiently localized in axons of the principal sensory thalamic nuclei over the first few postnatal weeks beginning at the middle of the first week. We first detect AChE-positive afferents histochemically in neocortex on embryonic day seventeen (E17) and determine that they arise from the principal sensory thalamic nuclei. AChE histochemistry labels the entire length of developing thalamocortical axons, including their growth cones and branches. These AChE-positive afferents enter the neocortex by the internal capsule and take an intracortical pathway centered on the subplate layer. As soon as these axons are detected, some have already begun to extend AChE-positive collateral branches superficially toward the cortical plate. By E19, a few collaterals have entered the deep part of the cortical plate and by E21 have densely invaded all but its most superficial undifferentiated part. AChE-positive afferents from basal forebrain structures reach the neocortex by three routes: the external capsule, the internal capsule, and the cingulate bundle. Among basal forebrain components, only the substantia innominata and nucleus basalis of Meynert reach the cortex by the internal capsule. Afferents from these two sources reach neocortex on E18, but are a very minor component of the total population of AChE-positive afferents at this age. Afferents from other basal forebrain components do not reach neocortex until several days later. The spatial and temporal patterns of AChE expression in developing thalamocortical axons indicate that it is useful for delineating their innervation of the primary sensory areas of embryonic neocortex, and suggest;that AChE may function in axon extension and cortical differentiation.