Caloric restriction prevents aging-associated changes in spike-mediated Ca2+ accumulation and the slow afterhyperpolarization in hippocampal CA1 pyramidal neurons

Neuroscience. 2005;135(2):413-20. doi: 10.1016/j.neuroscience.2005.05.044.

Abstract

In hippocampal pyramidal neurons from aged animals voltage-gated Ca2+ entry and the slow, post-burst afterhyperpolarization are enhanced. As a result, there is a decrease in neuronal excitability and, in turn, an alteration in synaptic plasticity. Restricting the caloric intake of a rodent is a well-known paradigm for increasing lifespan and ameliorating a number of neurodegenerative features of aging, including deficits in synaptic plasticity and cognition. Here we show in rat CA1 pyramidal neurons from aged animals (18-20 months old) that a restricted diet prevents the enhancement of dendritic spike-mediated Ca2+ accumulation. In contrast, no significant changes in the rates of Ca2+ recovery were observed suggesting that Ca2+ clearance mechanisms are not affected by aging or caloric restriction. Lastly, we found that caloric restriction also prevented the aging-associated increase in the slow, post-burst afterhyperpolarization. Our results suggest that caloric restriction-sensitive changes in Ca2+ accumulation and membrane excitability may in part account for the protective effects of dietary restriction on synaptic plasticity and learning deficits in aged animals.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology*
  • Aging / physiology*
  • Analysis of Variance
  • Animals
  • Calcium / metabolism*
  • Caloric Restriction*
  • Dendrites / physiology
  • Dendrites / radiation effects
  • Dose-Response Relationship, Radiation
  • Electric Stimulation / methods
  • Hippocampus / cytology*
  • In Vitro Techniques
  • Patch-Clamp Techniques / methods
  • Pyramidal Cells / cytology
  • Pyramidal Cells / physiology*
  • Rats
  • Rats, Inbred F344
  • Time Factors

Substances

  • Calcium