Topographically specific hippocampal projections target functionally distinct prefrontal areas in the rhesus monkey
Topographically specific hippocampal projections target functionally distinct prefrontal areas in the rhesus monkey
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DOI：
10.1002/hipo.450050604
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发表时间：
1995-01-01
期刊：
影响因子：
3.5
通讯作者：
Blatt, GJ
中科院分区：
文献类型：
--
作者：
Barbas, H;Blatt, GJ
用逆行示踪法研究了27只恒河猴同侧海马结构、前额叶前区、29a-c区和副下丘至内侧、眶和外侧前额叶皮质的投射来源。在海马体结构(CA1、CA1‘、原细束核和下丘脑)内的标记神经元位于吻侧，但有些标记神经元分布于整个海马体结构的吻尾部。大部分标记神经元投射到内侧前额叶皮质，其次是眼眶区域。此外，与眶皮质相比，投射到内侧的传入神经元的地形图也有所不同。分布于内侧皮质的标记神经元在吻侧主要分布在CA1‘和CA1区，而在尾侧主要起源于下丘脑区。相反，支配眼眶皮质的标记神经元定位更集中，从同一区域内同一相对位置发出，贯穿整个海马体结构的吻尾部。与向内侧和眶前额叶皮质的投射模式形成鲜明对比的是，外侧前额叶区域只接受少数标记神经元的投射，这些标记神经元大多位于丘脑下野。外侧前额叶皮质从前额叶前叶和前额叶上29a-c区得到最强的投射。眼眶和内侧前额叶区域接受来自丘脑前和29a-c区的较少但数量较多的神经元的投射。结果表明，前额叶皮质接受来自海马区不同成分的投射。内侧和眼眶前额叶皮质可能在长期助记过程中发挥作用，类似于与它们相连的海马结构相关的那些过程。此外，与眼眶前额叶区域相比，来自海马结构的投射神经元支配内侧区域的优势遵循了我们以前在杏仁核观察到的相反的趋势(Barbas和De Olmos[1990](I Comp Neurol 301：1-23))。因此，与记忆过程相关的海马结构主要针对内侧前额叶皮质，而与记忆的情感方面相关的杏仁核则向眼眶边缘皮质发出强有力的投射。外侧前额叶皮质接受来自穹隆前和29a-c区的强健投射，以及来自海马结构的稀疏投射。这些发现与外侧前额叶皮质在记忆中的作用不同于内侧或眼眶皮质的观点是一致的。结果表明，来自不同功能的边缘结构的信号在一定程度上沿着平行的路径到达功能不同的前额叶皮质。(C)1995年Wiley-Liss公司
The sources of ipsilateral projections from the hippocampal formation, the presubiculum, area 29a-c, and parasubiculum to medial, orbital, and lateral prefrontal cortices were studied with retrograde tracers in 27 rhesus monkeys. Labeled neurons within the hippocampal formation (CA1, CA1', prosubiculum, and subiculum) were found rostrally, although some were noted throughout the entire rostrocaudal extent of the hippocampal formation. Most labeled neurons in the hippocampal formation projected to medial prefrontal cortices, followed by orbital areas. In addition, there were differences in the topography of afferent neurons projecting to medial when compared with orbital cortices. Labeled neurons innervating medial cortices were found mainly in the CA1' and CA1 fields rostrally, but originated in the subicular fields caudally. In contrast, labeled neurons which innervated orbital cortices were considerably more focal, emanating from the same relative position within a field throughout the rostrocaudal extent of the hippocampal formation. In marked contrast to the pattern of projection to medial and orbital prefrontal cortices, lateral prefrontal areas received projections from only a few labeled neurons found mostly in the subicular fields. Lateral prefrontal cortices received the most robust projections from the presubiculum and the supracallosal area 29a-c. Orbital, and to a lesser extent medial, prefrontal areas received projections from a smaller but significant number of neurons from the presubiculum and area 29a-c. Only a few labeled neurons were found in the parasubiculum, and most projected to medial prefrontal areas.The results suggest that functionally distinct prefrontal cortices receive projections from different components of the hippocampal region. Medial and orbital prefrontal cortices may have a role in long-term mnemonic processes similar to those associated with the hippocampal formation with which they are linked. Moreover, the preponderance of projection neurons from the hippocampal formation innervating medial when compared with orbital prefrontal areas followed the opposite trend from what we had observed previously for the amygdala (Barbas and De Olmos [1990] (I Comp Neurol 301:1-23). Thus, the hippocampal formation, associated with mnemonic processes, targets predominantly medial prefrontal cortices, whereas the amygdala, associated with emotional aspects of memory, issues robust projections to orbital limbic cortices. Lateral prefrontal cortices receive robust projections from the presubiculum and area 29a-c and sparse projections from the hippocampal formation. These findings are consistent with the idea that the role of lateral prefrontal cortices in memory is distinct from that of either medial or orbital cortices. The results suggest that signals from functionally distinct limbic structures to some extent follow parallel pathways to functionally distinct prefrontal cortices. (C) 1995 Wiley-Liss, Inc.