Topographic Organization of Orbitofrontal Projections to the Parahippocampal Region in Rats
Topographic Organization of Orbitofrontal Projections to the Parahippocampal Region in Rats
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DOI：
10.1002/cne.23442
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发表时间：
2014-03-01
影响因子：
2.5
通讯作者：
Witter, Menno P.
中科院分区：
文献类型：
--
作者：
Kondo, Hideki;Witter, Menno P.
海马旁区域由鼻周皮质、幕后皮质、内嗅皮质以及副丘前叶组成，接受来自多个联合皮质的输入，并为海马区提供主要的皮质输入。本研究通过向大鼠眶前额叶皮质(OFC)的四个亚区注射生物素化葡聚糖胺(BDA)和菜豆亮氨酸凝集素(PHA-L)，研究了大鼠眼眶前额叶皮质(OFC)向海马旁区域投射的局部组织。口周皮质的吻侧部分接受内侧(MO)、腹侧(VO)和腹外(VLO)眶前区和外侧眶前区(LO)尾部的强投射。这些投射终止于鼻沟的背侧和底部。相反，后纹状体皮质接受来自VO的强烈投射。OFC的所有四个亚区均向外侧内嗅皮层的背外侧部分发出投射，并优先分布到更多的尾侧LEC。内侧内嗅皮层(MEC)接受来自VO的中等投射和来自MO、VLO和LO的弱投射。前丘接受来自尾侧VO的强投射，但只接受来自OFC其他区域的弱投射。至于投射的层状分布，来自OFC的轴突在海马区的上层(I-III层)比在深层终止得更密集。因此，这些结果表明OFC到海马旁的连接具有显著的地形图组织结构。LO、VLO、VO和MO与周围LEC环路相互作用，而与纹后皮质、丘脑前和MEC的相互作用主要通过VO的投射来调节。J.Comp.神经。2014年，522：772-793。(C)2013年威利期刊公司。
The parahippocampal region, which comprises the perirhinal, postrhinal, and entorhinal cortices, as well as the pre- and parasubiculum, receives inputs from several association cortices and provides the major cortical input to the hippocampus. This study examined the topographic organization of projections from the orbitofrontal cortex (OFC) to the parahippocampal region in rats by injecting anterograde tracers, biotinylated dextran amine (BDA) and Phaseolus vulgaris-leucoagglutinin (PHA-L), into four subdivisions of OFC. The rostral portion of the perirhinal cortex receives strong projections from the medial (MO), ventral (VO), and ventrolateral (VLO) orbitofrontal areas and the caudal portion of lateral orbitofrontal area (LO). These projections terminate in the dorsal bank and fundus of the rhinal sulcus. In contrast, the postrhinal cortex receives a strong projection specifically from VO. All four subdivisions of OFC give rise to projections to the dorsolateral parts of the lateral entorhinal cortex (LEC), preferentially distributing to more caudal levels of LEC. The medial entorhinal cortex (MEC) receives moderate input from VO and weak projections from MO, VLO, and LO. The presubiculum receives strong projections from caudal VO but only weak projections from other OFC regions. As for the laminar distribution of projections, axons originating from OFC terminate more densely in upper layers (layers I-III) than in deep layers in the parahippocampal region. These results thus show a striking topographic organization of OFC-to-parahippocampal connectivity. Whereas LO, VLO, VO, and MO interact with perirhinal-LEC circuits, the interactions with postrhinal cortex, presubiculum, and MEC are mediated predominantly through the projections of VO. J. Comp. Neurol. 522:772-793, 2014. (c) 2013 Wiley Periodicals, Inc.