Burwell R D, Amaral D G
Department of Psychology, Brown University, Providence, Rhode Island 02912, USA.
J Comp Neurol. 1998 Aug 24;398(2):179-205. doi: 10.1002/(sici)1096-9861(19980824)398:2<179::aid-cne3>3.0.co;2-y.
We have divided the cortical regions surrounding the rat hippocampus into three cytoarchitectonically discrete cortical regions, the perirhinal, the postrhinal, and the entorhinal cortices. These regions appear to be homologous to the monkey perirhinal, parahippocampal, and entorhinal cortices, respectively. The origin of cortical afferents to these regions is well-documented in the monkey but less is known about them in the rat. The present study investigated the origins of cortical input to the rat perirhinal (areas 35 and 36) and postrhinal cortices and the lateral and medial subdivisions of the entorhinal cortex (LEA and MEA) by placing injections of retrograde tracers at several locations within each region. For each experiment, the total numbers of retrogradely labeled cells (and cell densities) were estimated for 34 cortical regions. We found that the complement of cortical inputs differs for each of the five regions. Area 35 receives its heaviest input from entorhinal, piriform, and insular areas. Area 36 receives its heaviest projections from other temporal cortical regions such as ventral temporal association cortex. Area 36 also receives substantial input from insular and entorhinal areas. Whereas area 36 receives similar magnitudes of input from cortices subserving all sensory modalities, the heaviest projections to the postrhinal cortex originate in visual associational cortex and visuospatial areas such as the posterior parietal cortex. The cortical projections to the LEA are heavier than to the MEA and differ in origin. The LEA is primarily innervated by the perirhinal, insular, piriform, and postrhinal cortices. The MEA is primarily innervated by the piriform and postrhinal cortices, but also receives minor projections from retrosplenial, posterior parietal, and visual association areas.
我们已将大鼠海马体周围的皮质区域划分为三个细胞结构上不同的皮质区域，即嗅周皮质、嗅后皮质和内嗅皮质。这些区域似乎分别与猴子的嗅周皮质、海马旁皮质和内嗅皮质相对应。在猴子中，这些区域的皮质传入神经的起源已有充分记录，但在大鼠中对此了解较少。本研究通过在每个区域的几个位置注射逆行示踪剂，调查了大鼠嗅周皮质（35区和36区）、嗅后皮质以及内嗅皮质的外侧和内侧亚区（LEA和MEA）的皮质输入起源。对于每个实验，估计了34个皮质区域中逆行标记细胞的总数（以及细胞密度）。我们发现，五个区域各自的皮质输入组合有所不同。35区从内嗅皮质、梨状皮质和岛叶皮质接收的输入最多。36区从其他颞叶皮质区域，如腹侧颞叶联合皮质，接收的投射最多。36区也从岛叶皮质和内嗅皮质接收大量输入。虽然36区从服务于所有感觉模态的皮质接收的输入量相似，但投射到嗅后皮质的最重投射起源于视觉联合皮质和视觉空间区域，如顶叶后皮质。投射到LEA的皮质比投射到MEA的重，且起源不同。LEA主要由嗅周皮质、岛叶皮质、梨状皮质和嗅后皮质支配。MEA主要由梨状皮质和嗅后皮质支配，但也从压后皮质、顶叶后皮质和视觉联合区域接收少量投射。
