This intriguing part of the cerebral cortex was one of the first structures we studied, so papers range in publication from the 1960s to the 1990s. We did not include this work in the NEOCORTICAL DEVELOPMENT book because the hippocampus is archicortex, not neocortex (NC in photo at right). The hippocampus is a limbic system structure in the mammalian telencephalon concerned with exploratory behavior and attention; other studies link it to memory and spatial awareness. The major components of the hippocampal region are the hippocampus proper: Ammon’s horn [CA1, CA3] and the dentate gyrus [DG]. The subiculum (SU), presubiculum (PR), parasubiculum (PA), and the entorhinal cortex (EC) are other structures in the region. Our studies include its embryology, neurogenetic timetables, behavioral modifications after X-irradiation to remove dentate granule cells (see hippocampus and behavior page), and many adult neurogenesis studies (see the adult neurogenesis page).
Our brief communication shows that the immature hippocampus in children is a likely active zone for postnatal neurogenesis in the dentate granular layer, indicating that our findings in rats can be applied to humans.
BRIEF COMMUNICATION 1: POSTNATAL HIPPOCAMPAL NEUROGENESIS IN CHILDREN
Click below to open full E-book, titled:
The Hippocampal Region in a Horizontal Section (P60 Normal Rat)
From Bayer 1980 (1)
POSTNATAL NEUROGENESIS IN THE DENTATE GRANULAR LAYER
- labeled cells after 4 consecutive injections on P0 (birth) to P3;
- injections P4 to P7;
- injections P12 to P15;
- injections P16 to P19.
The general hypothesis we have formulated based on many correlations like these is: neurons are generated in exact sequences so that their axons and dendrites are available for innervation in the right times and places in the developing brain. Thus, the complex anatomical connections between parts of the adult nervous system are laid down during rigidly timed developmental events.