Chemically defined feedback connections from infragranular layers of sensory association cortices in the rat
Chemically defined feedback connections from infragranular layers of sensory association cortices in the rat
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DOI：
10.1016/j.neuroscience.2003.08.056
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发表时间：
2004-01-01
期刊：
影响因子：
3.3
通讯作者：
Arimatsu, Y
中科院分区：
文献类型：
--
作者：
Bai, WZ;Ishida, M;Arimatsu, Y
初级视觉（V1）、听觉（AI）和躯体感觉（SI）皮层与它们各自的感觉联合皮层相连。在大鼠中，我们以前已经证明，一些连接所产生的次级体感（SII）和顶叶岛（PA）皮质和终止在SI，其特征在于表达的latexin，一个候选蛋白的羧肽酶A抑制剂。在这里，通过使用逆行追踪和latexin免疫组织化学，我们表明，latexin表达神经元在其他联合皮层的不同感觉方式也有助于反馈投射到相应的初级感觉皮层。这些是次级视觉皮层（V2 L）的外侧部分，颞叶联合皮层，以及次级听觉带皮层的背腹侧部分。在V2 L、Allv和Sll的Via亚层内，大多数V1-、Al-和SI-投射神经元分别是Latexin免疫阳性的。与反馈连接相反，表达latexin的神经元很少参与胼胝体或半球内前馈连接。表达latexin的神经元构成了一个几乎完全不同的群体内的颗粒层皮质丘脑神经元。考虑到latexin可能通过控制蛋白酶活性参与神经元活动的调节，latexin表达反馈通路将在感觉知觉的调节中发挥独特的作用。(C)2003年IBRO。由爱思唯尔有限公司出版。保留所有权利。
The primary visual (V1), auditory (AI), and somatosensory (SI) cortices are reciprocally connected with their respective sensory association cortices. In the rat, we have previously demonstrated that some of the connections arising from the secondary somatosensory (SII) and parietal insular (PA) cortices and terminating in the SI, are characterized by the expression of latexin, a candidate protein of carboxypeptidase A inhibitor. Here, by using retrograde tracing and latexin-immunohistochemistry, we show that latexin-expressing neurons in other association cortices of different sensory modalities also contribute to the feedback projections to the corresponding primary sensory cortices. These are the lateral part of the secondary visual cortex (V2L), temporal association cortex, and the dorsal and ventral (Allv) parts of the secondary auditory belt cortex. Within sublayer Via of the V2L, Allv and Sll, the majority of the V1-, Al- and SI-projecting neurons respectively, are latexin-immunopositive. In contrast to feedback connections, far fewer latexin-expressing neurons participate in callosal or intrahemispheric feedforward connections. The latexin-expressing neurons constitute a virtually completely different population from corticothalamic neurons within the infragranular layers. Given that latexin might participate in the modulation of neuronal activity by controlling the protease activity, latexin-expressing feedback pathways would play a unique role in the modulation of sensory perception. (C) 2003 IBRO. Published by Elsevier Ltd. All rights reserved.