Effects of a high fat diet on brain metabolism in rats: An in vivo 1H-MRS study

Abstract

Diet-induced obesity and its metabolic consequences can lead to neurological dysfunction and increase the risk of developing Alzheimer's disease (AD) and Parkinson's disease (PD). Despite these realities, the effects of a high fat diet on the central nervous system are not well understood. To better understand effects of high fat consumption on the metabolic status of brain regions affected by AD and PD, we used magnetic resonance spectroscopy (1H-MRS) to measure neurochemicals in the hippocampus and in the striatum of rats fed a high-fat diet vs rats fed normal low-fat chow. We detected lower levels of total creatine (tCr: phosphocreatine; PCr + creatine; Cr) and higher glutamine in both the hippocampus and striatum of high fat-fed rats. Additional effects observed in the hippocampus included higher n-acetylaspartylglutamic acid (NAAG), and lower myo-inositol (Ins), gamma-Aminobutyric acid (GABA), and serine (Ser). Post-mortem tissue analyses revealed lower phosphorylated AMP-activated protein kinase (AMPK) and nuclear respiratory factor-1 (NRF-1) protein levels in the striatum but not the hippocampus. Overall, these changes indicate diet induced alterations in bioenergetic function and neurotransmission within both the hippocampal and striatal tissue.