Elsevier

Brain Research

Volume 168, Issue 3, 8 June 1979, Pages 485-492
Brain Research

Loss of axosomatic synapses in the dentate gyrus of aged rats

https://doi.org/10.1016/0006-8993(79)90304-4Get rights and content

Summary

Axosomatic synapses involving granule cells of the dentate gyrus were studied by means of quantitative electron microscopic analysis in young adult (3-month-old) and aged (25-month-old) rats. The number of axosomatic synapses per unit length of neuronal soma membrane was found to be significantly lower (by 15%) in aged animals than in young adults. This decrease in synaptic numbers is not associated with age-related changes in the size of neuronal soma profiles or in the length of their plasma membranes. The ratio between the total length of synaptic appositions and the membrane length of a neuronal soma profile was diminished by 22% in aged rats, whereas the mean length of synaptic apposition was 10% less in these animals than in young adults. These data, taken together, suggest that an absolute loss of axosomatic synapses occurs with advanced age. It appears, therefore, that not only the loss of axodendritic synapses, described previously, but also the loss of axosomatic synapses, found here, contributes to the process of age-related partial deafferentation of neurons in the rat dentate gyrus.

References (8)

  • GeinismanY. et al.

    Partial deafferentation of neurons in the dentate gyrus of the senescent rat

    Brain Research

    (1977)
  • ArtjukhinaN.I.

    An electron microscope study of ageing changes of synapses of the cerebral cortex of rats

    Tsitologia

    (1968)
  • ColemanG.L. et al.

    Pathological changes during aging in barrier-reared Fischer 344 male rats

    J. Geront.

    (1977)
  • GeinismanY. et al.

    Dendritic atrophy in the dentate gyrus of the senescent rat

    Amer. J. Anat.

    (1978)
There are more references available in the full text version of this article.

Cited by (0)

View full text