Topographic distribution of cortical projection cells in the rat subiculum. (March 2015)

• Record Type: Journal Article
• Authors: Honda, Yoshiko; Ishizuka, Norio
• Is Part Of: Neuroscience research. Volume 92(2015:Mar.)
• Page Start: 1
• Page End: 20
• Publication Date: 2015-03
• Subjects: AB angular bundle -- CA cornu ammonis -- cc corpus callosum -- DG dentate gyrus -- EC entorhinal cortex -- hf hippocampal fissure -- IS injection site -- LEC lateral entorhinal cortex -- MEC medial entorhinal cortex -- OCC occipital cortex -- Par parasubiculum -- Pre presubiculum -- PRh perirhinal cortex -- rf rhinal fissure -- RSG retrosplenial granular cortex -- RSA retrosplenial agranular cortex -- Sub subiculum; WGA-HRP -- Retrograde tracer -- Hippocampus -- Topography -- Memory; Neurosciences -- Research -- Periodicals; Neurosciences -- Research -- Japan -- Periodicals; Neurology -- Periodicals; Neurosciences -- Periodicals; Neurosciences -- Recherche -- Périodiques; Neurosciences -- Recherche -- Japon -- Périodiques; Neurosciences -- Research; Japan; Periodicals; 612.8
• DOI: 10.1016/j.neures.2014.11.011
• Languages: English
• ISSNs: 0168-0102

Abstract

Highlights: Cortical projection cells are widely located along the long axis of the subiculum. Most of the cortical projection cells are vertically located in the middle region. The deepest region of the subiculum contains few cortical projection cells. Topographical organization is observed in each subiculo-cortical projection. Abstract: The topographic distribution of subicular pyramidal cells, which give rise to projections to the entorhinal cortex, presubiculum, parasubiculum, and the retrosplenial granular cortex, was investigated in the rat using retrograde labeling with wheat germ agglutinin-horseradish peroxidase. Using two-dimensional unfolded maps of the entire hippocampal and parahippocampal fields, we found that the cells originating the projections to the above cortical areas were consistently observed throughout the entire septotemporal extent of the subiculum. In the transverse plane, most of the cortical projection cells were vertically located in the middle region of the subicular pyramidal cell layer. The cells giving rise to the projections to the lateral entorhinal cortex were predominantly located in the most proximal (near CA1), superficial region. Few cortical projection cells were located in the deepest (adjacent to the angular bundle) region. The distribution of cortical projection cells showed an oblique tri-laminar pattern, which was similar to the previously reported laminal pattern of subcortical projection cells in the subiculum. These results suggest that cortical projection cells in middle and superficial regions of the subiculum may correspond to layer V of the isocortex and cells in the deepest region corresponding to layer VI.