Department of Psychiatry and Behavioral Sciences, The MIND Institute and the California National Primate Research Center, Davis, California, USA.
J Comp Neurol. 2021 Mar;529(4):828-852. doi: 10.1002/cne.24983. Epub 2020 Aug 4.
The organization of projections from the macaque monkey hippocampus, subiculum, presubiculum, and parasubiculum to the entorhinal cortex was analyzed using anterograde and retrograde tracing techniques. Projections exclusively originate in the CA1 field of the hippocampus and in the subiculum, presubiculum, and parasubiculum. The CA1 and subicular projections terminate most densely in Layers V and VI of the entorhinal cortex, with sparser innervation of the deep portion of Layers III and II. Entorhinal projections from CA1 and the subiculum are topographically organized such that a rostrocaudal axis of origin is related to a medial-to-lateral axis of termination. A proximodistal axis of origin in CA1 and distoproximal axis in subiculum are related to a rostrocaudal axis of termination in the entorhinal cortex. The presubiculum sends a dense, bilateral projection to caudal parts of the entorhinal cortex. This projection terminates most densely in Layer III with sparser termination in Layers I, II, and V. The same parts of entorhinal cortex receive a dense projection from the parasubiculum. This projection terminates in Layers III and II. Both presubicular and parasubicular projections demonstrate the same longitudinal topographic organization as the projections from CA1 and the subiculum. These studies demonstrate that: (a) hippocampal and subicular inputs to the entorhinal cortex in the monkey are organized similar to those described in nonprimate species; (b) the topographic organization of the projections from the hippocampus and subicular areas matches that of the reciprocal projections from the entorhinal cortex to the hippocampus and the subicular areas.
使用顺行和逆行示踪技术分析了猕猴海马体、下托、前下托和副下托向内侧嗅皮层的投射组织。投射仅源自海马体的 CA1 区和下托、前下托和副下托。CA1 和下托的投射最密集地终止于内侧嗅皮层的第 V 和第 VI 层，第 III 和第 II 层的深部有较稀疏的神经支配。CA1 和下托的内侧嗅皮层投射呈拓扑组织，起源的前后轴与终止的内外轴相关。CA1 的近端-远端起源轴和下托的远端-近端起源轴与内侧嗅皮层终止的前后轴相关。前下托向内侧嗅皮层的尾部发出密集的双侧投射。该投射最密集地终止于第 III 层，在第 I、II 和第 V 层的终止较稀疏。内侧嗅皮层的相同部位接收来自副下托的密集投射。该投射终止于第 III 和第 II 层。前下托和副下托的投射都表现出与 CA1 和下托投射相同的纵向拓扑组织。这些研究表明：(a) 猴内侧嗅皮层的海马体和下托输入与非灵长类物种描述的相似；(b) 来自海马体和下托区的投射的拓扑组织与内侧嗅皮层到海马体和下托区的逆行投射的拓扑组织相匹配。
