Elemental changes in the hippocampal formation following two different formulas of ketogenic diet: an X-ray fluorescence microscopy study

Abstract

The main purpose of the following study was the determination of elemental changes occurring within hippocampal formation as a result of high-fat and carbohydrate-restricted ketogenic diet (KD). To realize it, X-ray fluorescence microscopy was applied for topographic and quantitative analysis of P, S, K, Ca, Fe, Cu, Zn and Se in hippocampal formations taken from rats fed with two different KDs and naive controls. The detailed comparisons were done for sectors 1 and 3 of the Ammon’s, the dentate gyrus and hilus of dentate gyrus. The results of elemental analysis showed that the KDs induced statistically significant changes in the accumulation of P, K, Ca, Zn and Se in particular areas of hippocampal formation and these alterations strongly depended on the composition of the diets. Much greater influence on the hippocampal areal densities of examined elements was found for the KD which was characterized by a lower content of carbohydrates, higher content of fats and increased proportion of unsaturated fatty acids. The levels of P, K and Zn decreased whilst those of Ca and Se increased as a result of the treatment with the KDs.

Various ketogenic diets can differently support brain resistance against experimentally evoked seizures and seizure-induced elemental anomalies of hippocampal formation

“…Although, the content of PUFAs was slightly higher in KD1 comparing to KD2, lower ketogenic ratio KD did not induce significant changes in the unsaturation level of lipids within the hippocampal formation of normal rats [22]. From the other side, such effect was observed for animals treated with KD2 in which the content of unsaturated fatty acids was significantly higher comparing to rats on the standard diet [20]. Therefore, rather the increased hippocampal level of PUFAs than ketone bodies may be linked with the effectiveness of KD in the treatment of epilepsy.…”

“…The analysis of the influence of KDs 1 and 2 on the elemental composition of normal hippocampal formation was the subject of our previous paper published in JBIC in 2015 [20]. The results presented there showed that KD induced significant elemental changes in the particular areas of hippocampal formation.…”

“…Our previous studies carried out on different models of seizures showed that monitoring the hippocampal levels of Ca, Fe, Cu and Zn we can gain very important information about the pathogenesis and progress of epilepsy as well as about the neuroprotective and/or antiseizure action of particular drugs or diets [20][21][22][26][27][28][29][30]. Moreover, the existing evidence shows that the data on the elemental composition of this brain area can positively influence the research on the role of metals in the Alzheimer's disease or their use as contrast agents in magnetic resonance imaging [31][32][33].…”

“…The KDs with higher ketogenic ratios are usually more efficient in the seizure control but may be worse tolerate by the patients [19]. Our previous investigations showed, moreover, that elemental and biochemical changes occurring in the hippocampal formation after KD depended on its composition [20][21][22]. This suggests that also the mechanisms of anticonvulsive action of different KDs may not be the same.…”

“…In turn, the animals on the KD1 had increased level of Se in all hippocampal regions, but this relation was statistically significant only in the hilus of DG. The detailed interpretation of these results was presented elsewhere [20].…”