dentate gyrus

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Introduction

One of the 2 interlocking gyri composing the hippocampus. The other is the cornu ammonis (Ammon horn).

Structure

The dentate gyrus consists of 3 layers

The principal cell layer of the dentate gyrus is the granule cell layer, with a prominant dendritic arborization (molecular layer).

The granule cell & molecular layer are often referred to as the fascia dentata.

The hilus of the dentate gyrus contains neuroblasts that form granule cells from birth into old age.

Newly formed granule cells accumulate under the older granule cells gradually increasing the thickness of the granule layer throughout life

The human dentate gyrus contains about 9 x 10E6 granule cells.

Afferents

Efferents

Local projections:

Comparative biology

* if neurogenesis were to persist throughout aging from age 14-79 & newly formed granule cells were to accumulate under the older granule cells gradually increasing the thickness of the granule layer, volume of the dentate gyrus should increase throughout aging; ref[5] reports no change in dentate gyrus volume from age 14-79

* it is also noted the ref[4] reports that neurogenesis in the human hippocampus ceases by age 13

More general terms

Additional terms

Component of

Components

References

  1. Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999
  2. The Human Nervous System, George Paxinos, Academic Press, San Diego CA 1990
  3. Wikipedia: Dentate gyrus https://en.wikipedia.org/wiki/Dentate_gyrus
  4. 4.0 4.1 4.2 Sorrells SF, Paredes MF, Cebrian-Silla A Human hippocampal neurogenesis drops sharply in children to undetectable levels in adults. Nature. April 6, 2018. Published Online March 7, 2018 PMID: https://www.ncbi.nlm.nih.gov/pubmed/29513649 https://www.nature.com/articles/nature25975
  5. 5.0 5.1 5.2 Boldrini M, Fulmore CA, Tartt AN et al Human Hippocampal Neurogenesis Persists throughout Aging. Cell Stem Cell. April 5, 2018. 22(4):589 PMID: https://www.ncbi.nlm.nih.gov/pubmed/29625071 https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(18)30121-8