Corticocortical and thalamocortical projections to layer I of the frontal neocortex in rats
Corticocortical and thalamocortical projections to layer I of the frontal neocortex in rats
复制标题
大鼠额叶新皮质 I 层的皮质和丘脑皮质投射
DOI：
10.1016/s0006-8993(01)03084-0
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发表时间：
2001
期刊：
影响因子：
2.9
通讯作者：
L. Cauller
中科院分区：
文献类型：
--
作者：
B. Mitchell;L. Cauller
新皮质的第I层是一个致密的突触带，除了丘脑的输入外，还有水平的皮质和广泛的第VII层投射。为了确定皮质和丘脑皮质投射到大鼠新皮质前额/运动前区M2层的来源和范围，我们用荧光解剖学方法确定了皮质和丘脑在M2层I层的头侧和尾侧的精确来源。逆行示踪剂二胺基黄(DY)，直接应用于大鼠M2区(分别为RM2和CM2)的软脑膜表面，标记的细胞遍及相邻主运动区和顶区(SI和SII)的II/III、V和VII层。此外，在与CM2或RM2应用部位同位的第II/III层和第V层，标记了对侧CM2或RM2的逆行运输。对侧VII层由CM2的第I层应用逆行标记，而不是RM2应用逆行标记。在丘脑腹内侧核(Vm)、腹外侧核(VL)和后核(Po)可见DY从RM2或CM2的I层逆行运输。然而，CM2的I层运输额外标记了丘脑中央内侧核，而RM2标记了丘脑内侧核。在确定丘脑Vm和VL核是本研究的主要目标后，由于其密集的逆行标记，我们将顺行示踪剂罗丹明右旋糖胺(RDA)注射到Vm或VL，以研究这些核团向额叶皮质I层的投射模式。RDA注射到Vm标记纤维，穿过RM2和CM2的I层和整个扣带皮质。将RDA注入VL，在CM2和RM2的I层都有一致标记的致密纤维，尽管标记在CM2之前急剧减少。这项研究增加了越来越多的证据，证明从所有来源的皮质输入到I层的投射对整个新皮质的整合有重大贡献。
Layer I of the neocortex is a dense synaptic zone consisting of horizontal corticocortical and widespread layer VII projections, in addition to thalamic inputs. In order to determine the origin and extent of corticocortical and thalamocortical projections to layer I of the frontal/premotor area M2 of the rat neocortex, we have used fluorescent anatomical tracing methods to determine the precise sources of cortical and thalamic input to the rostral and caudal aspects of layer I of M2. Retrograde tracer diamidino yellow (DY), applied directly to the pial surface on rostral or caudal areas of rat M2 (RM2 and CM2, respectively) labeled cells ipsilaterally throughout layers II/III, V, and VII of the adjacent primary motor area and the parietal areas (SI and SII). In addition, retrograde transport labeled contralateral CM2 or RM2 in layers II/III and V at sites homotopic to either CM2 or RM2 application sites. Contralateral layer VII was retrogradely labeled by the application to layer I of CM2, but not by the RM2 application. Retrograde DY transport from layer I of RM2 or CM2 of was seen in the ventral medial (VM), ventral lateral (VL), and posterior (Po) thalamic nuclei. However layer I transport from CM2 additionally labeled the thalamic central medial (CM) nucleus, while the RM2 labeled the mediodorsal (MD) thalamic nucleus. Upon determination that thalamic nuclei VM and VL were of primary interest in this study, due to their dense retrograde labeling, injections of anterograde tracer rhodamine dextranamine (RDA) into VM or VL were performed in order to study the projection patterns of these nuclei to layer I of the frontal cortex. RDA injections into VM labeled fibers extending through layer I of both RM2 and CM2 and throughout the cingulate cortex. Injections of RDA into VL consistently labeled dense fibers in layer I of both CM2 and RM2, although labeling was sharply decreased anterior to CM2. This study adds to a growing body of evidence that projections to layer I from all sources of cortical input make a significant contribution to integration throughout the neocortex.
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影响因子：
3.7
作者：
Felleman, Daniel J.;Van Essen, David C.
通讯作者：
Van Essen, David C.
影响因子：
3.7
作者：
BARBAS, H
通讯作者：
BARBAS, H
影响因子：
3.7
作者：
Barbas, H;RempelClower, N
通讯作者：
RempelClower, N
影响因子：
2.5
作者：
BARBAS, H;PANDYA, DN
通讯作者：
PANDYA, DN