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Diet‐induced insulin resistance impairs hippocampal synaptic plasticity and cognition in middle‐aged rats
Author(s) -
Stranahan Alexis M.,
Norman Eric D.,
Lee Kim,
Cutler Roy G.,
Telljohann Richard S.,
Egan Josephine M.,
Mattson Mark P.
Publication year - 2008
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.20470
Subject(s) - long term potentiation , hippocampus , schaffer collateral , dendritic spine , hippocampal formation , synaptic plasticity , neuroscience , neurotrophic factors , endocrinology , medicine , neuroplasticity , psychology , receptor
Overall dietary energy intake, particularly the consumption of simple sugars such as fructose, has been increasing steadily in Western societies, but the effects of such diets on the brain are poorly understood. Here, we used functional and structural assays to characterize the effects of excessive caloric intake on the hippocampus, a brain region important for learning and memory. Rats fed with a high‐fat, high‐glucose diet supplemented with high‐fructose corn syrup showed alterations in energy and lipid metabolism similar to clinical diabetes, with elevated fasting glucose and increased cholesterol and triglycerides. Rats maintained on this diet for 8 months exhibited impaired spatial learning ability, reduced hippocampal dendritic spine density, and reduced long‐term potentiation at Schaffer collateral—CA1 synapses. These changes occurred concurrently with reductions in levels of brain‐derived neurotrophic factor in the hippocampus. We conclude that a high‐calorie diet reduces hippocampal synaptic plasticity and impairs cognitive function, possibly through BDNF‐mediated effects on dendritic spines. Published 2008 Wiley‐Liss, Inc.