Mosaic organization of the hippocampal neuroepithelium and the multiple germinal sources of dentate granule cells

Journal Article · Thu Nov 15 04:00:00 EST 1990 · Journal of Comparative Neurology; (USA)

DOI:https://doi.org/10.1002/cne.903010302· OSTI ID:6213886

Altman, J; Bayer, S A ^[1]

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1. Purdue Univ., West Lafayette, IN (USA)

This study deals with the site of origin, migration, and settling of the principal cell constituents of the rat hippocampus during the embryonic period. The results indicate that the hippocampal neuroepithelium consists of three morphogenetically discrete components--the Ammonic neuroepithelium, the primary dentate neuroepithelium, and the fimbrial glioepithelium--and that these are discrete sources of the large neurons of Ammon's horn, the smaller granular neurons of the dentate gyrus, and the glial cells of the fimbria. The putative Ammonic neuroepithelium is marked in short-survival thymidine radiograms by a high level of proliferative activity and evidence of interkinetic nuclear migration from day E16 until day E19. On days E16 and E17 a diffuse band of unlabeled cells forms outside the Ammonic neuroepithelium. These postmitotic cells are considered to be stratum radiatum and stratum oriens neurons, which are produced in large numbers as early as day E15. A cell-dense layer, the incipient stratum pyramidale, begins to form on day E18 and spindle-shaped cells can be traced to it from the Ammonic neuroepithelium. This migratory band increases in size for several days, then declines, and finally disappears by day E22. It is inferred that this migration contains the pyramidal cells of Ammon's horn that are produced mostly on days E17 through E20. The putative primary dentate neuroepithelium is distinguished from the Ammonic neuroepithelium during the early phases of embryonic development by its location, shape, and cellular dynamics. It is located around a ventricular indentation, the dentate notch, contains fewer mitotic cells near the lumen of the ventricle than the Ammonic neuroepithelium, and shows a different labeling pattern both in short-survival and sequential-survival thymidine radiograms.

• OSTI ID: 6213886
• Journal Information: Journal of Comparative Neurology; (USA), Journal Name: Journal of Comparative Neurology; (USA) Vol. 301:3; ISSN 0021-9967; ISSN JCNEA
• Country of Publication: United States
• Language: English

Related Subjects

550301* -- Cytology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
AUTORADIOGRAPHY
AZINES
BODY
BRAIN
CELL PROLIFERATION
CENTRAL NERVOUS SYSTEM
EMBRYOS
EPITHELIUM
HETEROCYCLIC COMPOUNDS
HIPPOCAMPUS
HYDROGEN COMPOUNDS
MAMMALS
NERVE CELLS
NERVOUS SYSTEM
NUCLEOSIDES
NUCLEOTIDES
ONTOGENESIS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PYRIMIDINES
RATS
RIBOSIDES
RODENTS
SOMATIC CELLS
SURVIVAL TIME
THYMIDINE
TISSUES
TRITIUM COMPOUNDS
VERTEBRATES