DHA supplementation enhances high-frequency, stimulation-induced synaptic transmission in mouse hippocampus

Appl Physiol Nutr Metab. 2012 Oct;37(5):880-7. doi: 10.1139/h2012-062. Epub 2012 Jun 20.

Abstract

While some studies on dietary supplementation with docosahexaenoic acid (DHA, 22:6n-3) have reported a beneficial effect on memory as a function of age, others have failed to find any effect. To clarify this issue, we sought to determine whether supplementing mice with a DHA-enriched diet could alter the ability of synapses to undergo activity-dependent changes in the hippocampus, a brain structure involved in forming new spatial memories. We found that DHA was increased by 29% ± 5% (mean ± SE) in the hippocampus for the supplemented (DHA+) versus nonsupplemented (control) group (n = 5 mice per group; p < 0.05). Such DHA elevation was associated with enhanced synaptic transmission (p < 0.05) as assessed by application of a high-frequency electrical stimulation protocol (100 Hz stimulation, which induced transient (<2 h) increases in synaptic strength) to slices from DHA+ (n = 4 mice) hippocampi when compared with controls (n = 4 mice). Increased synaptic responses were evident 60 min poststimulation. These results suggest that dietary DHA supplementation facilitates synaptic plasticity following brief high-frequency stimulation. This increase in synaptic transmission might provide a physiological correlation for the improved spatial learning and memory observed following DHA supplementation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CA1 Region, Hippocampal / chemistry
  • CA1 Region, Hippocampal / physiology
  • Dietary Supplements*
  • Docosahexaenoic Acids / metabolism*
  • Electric Stimulation / methods
  • Hippocampus / chemistry
  • Hippocampus / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Neuronal Plasticity*
  • Neurons / chemistry
  • Neurons / physiology*
  • Nootropic Agents / metabolism*
  • Perfusion
  • Synaptic Potentials
  • Synaptic Transmission*
  • Time Factors

Substances

  • Nootropic Agents
  • Docosahexaenoic Acids