Autophagy is Protective in the Progression Towards Age-Related Hearing Loss

This open access paper provides a good summary of present thought on the contributing causes of hearing loss, in which the various issues of noise, aging, and toxicity cause harm via inducing stress in hair cells of the inner ear and their axonal connections to the brain. Autophagy is a cell maintenance process, the recycling of damaged component parts. More efficient autophagy helps hair cells to resist and survive a stressful environments, but autophagy declines with age. Defects arise in many of the component parts of the autophagic system and its regulation. This is likely why the threshold for loss of hair cells in response to stresses diminishes in later life, leading to the onset of hearing loss in a large fraction of the population. Hearing loss is not only a physical and financial burden in social life, but also causes psychological problems and psychiatric disorders, including cognitive decline and depression. Genetic alterations, noise, ototoxic drugs, and aging can all contribute to hearing loss. Although the causes vary, the most common causes of deafness are damage or loss of hair cells (HCs) and degeneration of spiral ganglion neurons (SGNs). HCs are responsible for converting external sound signals into electrical signals that are transmitted to the brainstem through SGNs. Recent studies have shown that these sensory cells cannot spontaneously regenerate in adult mammals, so damage or loss of HCs and degeneration of SGNs can result in permanent deafn...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs