Early-Age Running Enhances Activity of Adult-Born Dentate Granule Neurons Following Learning in Rats

eNeuro. 2017 Aug 16;4(4):ENEURO.0237-17.2017. doi: 10.1523/ENEURO.0237-17.2017. eCollection Jul-Aug 2017.

Abstract

Cognitive reserve, the brain's capacity to draw on enriching experiences during youth, is believed to protect against memory loss associated with a decline in hippocampal function, as seen in normal aging and neurodegenerative disease. Adult neurogenesis has been suggested as a specific mechanism involved in cognitive (or neurogenic) reserve. The first objective of this study was to compare learning-related neuronal activity in adult-born versus developmentally born hippocampal neurons in juvenile male rats that had engaged in extensive running activity during early development or reared in a standard laboratory environment. The second objective was to investigate the long-term effect of exercise in rats on learning and memory of a contextual fear (CF) response later in adulthood. These aims address the important question as to whether exercise in early life is sufficient to build a reserve that protects against the process of cognitive aging. The results reveal a long-term effect of early running on adult-born dentate granule neurons and a special role for adult-born neurons in contextual memory, in a manner that is consistent with the neurogenic reserve hypothesis.

Keywords: adult neurogenesis; dentate gyrus; hippocampus; learning and memory; plasticity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / physiology*
  • Analysis of Variance
  • Animals
  • Cell Count
  • Dentate Gyrus / cytology*
  • Dentate Gyrus / physiology
  • Fear / physiology*
  • Gene Expression Regulation / physiology
  • Learning / physiology*
  • Male
  • Memory / physiology
  • Neurons / physiology*
  • Physical Conditioning, Animal / physiology*
  • Proto-Oncogene Proteins c-fos / metabolism
  • Rats
  • Rats, Long-Evans
  • Running

Substances

  • Proto-Oncogene Proteins c-fos