Research Paper Volume 12, Issue 19 pp 19493—19519
Accelerated age-related decline in hippocampal neurogenesis in mice with noise-induced hearing loss is associated with hippocampal microglial degeneration
- 1 Department of Physiology, Medical College, Southeast University, Nanjing 210009, China
- 2 Institute of Life Sciences, Southeast University, Nanjing 210096, China
- 3 Medical College, Southeast University, Nanjing 210009, China
- 4 Kangda College of Nanjing Medical University, Lianyungang 222000, China
- 5 School of Human Communication Disorder, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
- 6 Center for Hearing and Deafness, University at Buffalo, The State University of New York, Buffalo, NY 14214, USA
- 7 Jiangsu Key Laboratory of Molecular Imaging and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing 210009, China
Received: April 3, 2020 Accepted: July 23, 2020 Published: October 11, 2020
https://doi.org/10.18632/aging.103898How to Cite
Copyright: © 2020 Zhuang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Large-scale epidemiological surveys suggest that hearing loss (HL) is a significant risk factor for dementia. We previously showed that noise-induced HL (NIHL) impairs hippocampal cognitive function and decreases hippocampal neurogenesis and neuronal complexity, suggesting a causal role of HL in dementia. To further investigate the influence of acquired peripheral HL on hippocampal neurogenesis with the aging process as well as the underlying mechanism, we produced NIHL in male CBA/J mice and assessed hippocampal neurogenesis and microglial morphology in the auditory brain and hippocampus at 4 days post-noise exposure (DPN) or 1, 3, 6, or 12 months post-noise exposure (MPN) by immunofluorescence labeling. We found that the age-related decline in hippocampal neurogenesis was accelerated in mice with NIHL. Furthermore, in mice with NIHL, prolonged microglial activation occurred from 1 MPN to 12 MPN across multiple auditory nuclei, while aggravated microglial deterioration occurred in the hippocampus and correlated with the age-related decline in hippocampal neurogenesis. These results suggest that acquired peripheral HL accelerates the age-related decline in hippocampal neurogenesis and that hippocampal microglial degeneration may contribute to the development of neurodegeneration following acquired peripheral HL.