Age-Related Changes of Elements and Relationships Among Elements in Human Hippocampus, Dentate Gyrus, and Fornix

Abstract

To elucidate compositional changes of the limbic system with aging, the authors investigated age-related changes of elements in the hippocampus, dentate gyrus, and fornix and the relationships among elements by direct chemical analysis. After ordinary dissections at Nara Medical University were finished, the hippocampi, dentate gyri, and fornices were resected from identical cerebra of the subjects which consisted of 23 men and 23 women, ranging in age from 70 to 101 years. After ashing with nitric acid and perchloric acid, element contents were determined by inductively coupled plasma-atomic emission spectrometry. The average contents of P, Zn, and Na were significantly less in both the hippocampi and dentate gyri compared with the fornices. It was found that the Ca and Mg contents increased significantly in the hippocampus with aging; the P content increased significantly in the dentate gyrus with aging, whereas the Na content decreased in the dentate gyrus with aging; and the Mg content increased significantly in the fornix with aging. Regarding the relationships among elements, a significant direct correlation between Ca and Fe contents and an extremely significant inverse correlation between P and Zn contents were found in both the hippocampi and dentate gyri. In addition, a significant direct correlation between P and Mg contents was found in both the hippocampi and fornices. Pearson's correlation was used to examine whether there were elements with significant correlation among the hippocampus, dentate gyrus, fornix, and mammillary body. Significant correlations were found in five elements of Ca, P, Mg, Zn, and Fe except for S and Na among the hippocampus, dentate gyrus, and mammillary body with one exception. Regarding the fornix, significant correlations were found in two elements of P and Fe between the fornix and hippocampus, dentate gyrus, or mammillary body.

Age-Related Changes in Diffusion Tensor Imaging Metrics of Fornix Subregions in Healthy Humans

“…These results suggest that, even within a clearly labeled tract such as the anterior fornix, its diffusivity changes can be highly heterogeneous. Our results are consistent with other literature which reports decreased FA values in the fornix with age [37,38]. While studies have shown that age-independent demyelination or axonal injury strongly correlates with specific DTI metrics such as RD or AD, respectively [39,40,41], it is unsurprising to see changes in FA, AD and RD in our current study sample given that multiple events involving different aspects of white matter integrity are involved in aging.…”

“…While it is known that the volume of the hippocampus decreases with age [38,44,45], we did not observe a significant decline in hippocampal volume in our group of healthy subjects. Longitudinal studies have demonstrated that there is whole-brain, and especially hippocampal, atrophy with age which correlates with a decline in cognition [46].…”

Minor and Trace Elements in Cerebrospinal Fluid of Parkinson's Patients – Suggestions After a Critical Review of the Analytical Data

“…In serum, it has been documented for Cu by Ghayour-Mobarhan et al (2005) and Kouremenou-Dona et al (2006); for Se by Lopes et al (2004). In brain, Markesbery et al (1984), Ongkana et al (2010) and Tohno et al (2010)  data converted from nmol/L Table 6. Manganese in Controls and Patients (µg/L) elements.…”

Relationships Among the Hippocampus, Dentate Gyrus, Mammillary Body, Fornix, and Anterior Commissure from a Viewpoint of Elements

“…Therefore, myelin has a selectively high P concentration with low levels of other elements [17,18]. Recently, the authors examined the P content in both the white and gray matters of the brain and confirmed that the P content was higher in the white matter than in the gray matter [3]. Riehemann et al [19] investigated the concentrations of different phosphorus compounds in the frontal lobe of 32 healthy subjects by image selected in vivo spectroscopy sequence on a whole-body scanner and reported that healthy females exhibited increased values of inorganic phosphate and decreased values of phosphocreatine in comparison to their male counterparts.…”

“…To elucidate compositional changes of the brain with aging, the authors previously investigated age-related changes of elements in the corpus callosum [1], anterior commissure [2], and fornix [3] of the white matter and the pineal body [4], olfactory bulb and tract [5], mammillary body [6], hippocampus, and dentate gyrus [3] of the gray matter and found that the Ca content increased significantly in the mammillary body and hippocampus with aging, and the Mg content increased significantly in the hippocampus and fornix with aging.…”