Effect of high-fat diet and antioxidants on hippocampal long-term potentiation in rats: an in vivo study.

The objective of this study was to determine the relation between the chronic consumption of a high-fat diet (HFD) and antioxidants on long-term potentiation (LTP) in dentate gyrus (DG) of the adult rat hippocampus in vivo. Forty adult male Wistar rats were randomly assigned into five groups (N=6-8): control group consumed an ordinary diet; HFD group received HFD only; ANO group received HFD plus antioxidants; RHFD group received a restricted HFD (30% less fat than the HFD group); and RANO group received restricted HFD plus antioxidants. Following 6 months of controlled diets in each experimental group, the rats were anesthetized with intraperitoneal injection of ketamine and xylazin (100 and 2.5 mg/kg, respectively), and placed into a stereotaxic apparatus for surgery, electrode implantation and field potential recording. The population spike (PS) amplitude and slope of excitatory post synaptic potentials (EPSP) were measured in DG area of adult rats in response to stimulation applied to the perforant pathway (PP) by 400 Hz tetanization. The results showed that HFD decreased EPSP slope and PS amplitude with respect to the control group, whereas antioxidants increased these parameters compared to the control group. It was suggested that chronic HFD consumption can impair hippocampal LTP in the granular cells of the DG, and antioxidant supplementation reverses the impairment of synaptic plasticity induced in DG.