Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2022 Feb;12(2):55.
doi: 10.1007/s13205-022-03123-4. Epub 2022 Feb 1.

Hippocampus and its involvement in Alzheimer's disease: a review

Y Lakshmisha Rao  1 , B Ganaraja  2 , B V Murlimanju  1 , Teresa Joy  3 , Ashwin Krishnamurthy  4 , Amit Agrawal  5
Affiliations
Review

Hippocampus and its involvement in Alzheimer's disease: a review

Y Lakshmisha Rao et al. 3 Biotech. 2022 Feb.

Abstract

Hippocampus is the significant component of the limbic lobe, which is further subdivided into the dentate gyrus and parts of Cornu Ammonis. It is the crucial region for learning and memory; its sub-regions aid in the generation of episodic memory. However, the hippocampus is one of the brain areas affected by Alzheimer's (AD). In the early stages of AD, the hippocampus shows rapid loss of its tissue, which is associated with the functional disconnection with other parts of the brain. In the progression of AD, atrophy of medial temporal and hippocampal regions are the structural markers in magnetic resonance imaging (MRI). Lack of sirtuin (SIRT) expression in the hippocampal neurons will impair cognitive function, including recent memory and spatial learning. Proliferation, differentiation, and migrations are the steps involved in adult neurogenesis. The microglia in the hippocampal region are more immunologically active than the other regions of the brain. Intrinsic factors like hormones, glia, and vascular nourishment are instrumental in the neural stem cell (NSC) functions by maintaining the brain's microenvironment. Along with the intrinsic factors, many extrinsic factors like dietary intake and physical activity may also influence the NSCs. Hence, pro-neurogenic lifestyle could delay neurodegeneration.

Keywords: Alzheimer’s disease; Hippocampus; Sirtuin 1; Tau proteins.

PubMed Disclaimer

Conflict of interest statement

Conflict of interestThe authors of this manuscript declare that there are no conflicts of interest associated with this manuscript.

Figures

Fig. 1
Fig. 1
Afferent and efferent connections of hippocampus
Fig. 2
Fig. 2
Cresyl violet staining in an Albino Wistar rat model showing (2x) the subdivisions of hippocampus (DG-dentate gyrus; CA1-cornu ammonis region 1; CA2-cornu ammonis region 2; CA3-cornu ammonis region 3; CA4-cornu ammonis region 4)
See this image and copyright information in PMC

References

    1. Abbott LC, Nigussie F. Adult neurogenesis in the mammalian dentate gyrus. Anat Histol Embryol. 2020;49(1):3–16. - PubMed
    1. Altman J, Das GD. Autoradiographic and histological evidence of postnatal hippocampal neurogenesis in rats. J Comp Neurol. 1965;124(3):319–335. - PubMed
    1. Androutsellis-Theotokis A, Murase S, Boyd JD, Park DM, Hoeppner DJ, Ravin R, McKay RD. Generating neurons from stem cells. Methods Mol Biol. 2008;438:31–38. - PubMed
    1. Asai H, Ohkawa N, Saitoh Y, Ghandour K, Murayama E, Nishizono H, Matsuo M, Hirayama T, Kaneko R, Muramatsu SI, Yagi T, Inokuchi K. Pcdhβ deficiency affects hippocampal CA1 ensemble activity and contextual fear discrimination. Mol Brain. 2020;13(1):7. - PMC - PubMed
    1. Bachstetter AD, Van Eldik LJ, Schmitt FA, Neltner JH, Ighodaro ET, Webster SJ, Patel E, Abner EL, Kryscio RJ, Nelson PT. Disease-related microglia heterogeneity in the hippocampus of Alzheimer's disease, dementia with Lewy bodies, and hippocampal sclerosis of aging. Acta Neuropathol Commun. 2015;3:32. - PMC - PubMed

LinkOut - more resources