Exposure to a diet high in fat attenuates dendritic spine density in the medial prefrontal cortex
A key factor in the development of obesity is the overconsumption of food calorically high in fat. Overconsumption of food high in fat not only promotes weight gain but elicits changes in reward processing. No studies to date have examined whether consumption of a high-fat (HF) diet alters structural plasticity in brain areas critical for reward processing, which may account for persistent changes in behavior and psychological function by reorganizing synaptic connectivity. To test whether dietary fat may induce structural plasticity we placed rats on one of three dietary conditions: ad libitum standard chow (SC), ad libitum 60 % HF (HF-AL), or calorically matched 60 % HF (HF-CM) for 3 weeks and then quantified dendritic spine density and type on basal and apical dendrites of pyramidal cells in layer V of the medial prefrontal cortex (mPFC) and medium spiny neurons (MSNs) of the nucleus accumbens. Our results demonstrate a significant reduction in the density of thin spines on the apical and basal segments of dendrites within the infralimbic, but not prelimbic, mPFC.
KeywordsHigh-fat Prefrontal cortex Plasticity Dendritic spines
The authors would like to thank Dr. Zhaojie Zhang, the director of the Neuroscience microscopy facility at the University of Wyoming, for his help and guidance imaging the spine data. We would also like to thank Kevin Schlidt and Morgan Deters for their assistance with animal care. We are also grateful for the support contributed by NIGMS grant P30 GM103398, and the College of Health Sciences Seed Grant from the University of Wyoming.