Predicting the effects of a high-energy diet on fatty liver and hippocampal-dependent memory in male rats

Obesity (Silver Spring). 2013 May;21(5):910-7. doi: 10.1002/oby.20167.

Abstract

Objective: In rodents, diets exceeding nutritional requirements (i.e., high-energy diets; HED) impair hippocampal-dependent memory. Our research suggests that the effects likely involve HED-induced increases in liver lipids. In this experiment, rats were provided with diet choices to test whether voluntary consumption of a HED impairs spatial memory, whether differences in initial weight gain predict memory deficits, and whether increases in liver lipids are associated with the memory deficits.

Design and methods: Adult male Sprague-Dawley rats were given a control diet or cafeteria-style HED for 8 weeks. Weight gain during the first 5 days on the diet was used to divide rats into a HED-Lean group and a HED-Obese group. Spatial water maze memory was tested 8 weeks later and postmortem liver lipid concentrations were quantified.

Results: Compared with the HED-Lean and control rats, the HED-Obese rats had impaired spatial memory and met the human diagnostic criterion of non-alcoholic fatty liver disease (>5% liver lipids relative to liver weight). Moreover, liver lipids were correlated with memory deficits.

Conclusions: These findings show that voluntary consumption of a HED impairs memory, that initial weight gain predicts fatty liver and memory deficits, and that fatty liver may contribute to the memory-impairing effects of obesity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diet
  • Energy Intake*
  • Fatty Liver / etiology*
  • Fatty Liver / metabolism
  • Hippocampus*
  • Lipid Metabolism*
  • Liver / metabolism
  • Male
  • Maze Learning
  • Memory Disorders / etiology*
  • Memory Disorders / metabolism
  • Memory*
  • Non-alcoholic Fatty Liver Disease
  • Obesity* / metabolism
  • Obesity* / psychology
  • Rats
  • Rats, Sprague-Dawley
  • Weight Gain / physiology