Dietary supplementation with phytosterols — plant sterols with structure and function similar to cholesterol — prevented sensory dysfunction in lab mice.
“Functional deterioration of the nervous system is frequently observed in the elderly, with a progressive decline in cognitive capacities,” said Dr. María Eugenia Gomez-Casati, a researcher at the Universidad de Buenos Aires and CONICET, and her colleagues.
“Age-related hearing loss is a significant problem that leads to a reduced hearing perception, with almost 1 in 3 adults over age 65 experiencing some degree of hearing loss.”
“Age-related hearing loss typically initiates with a loss of synaptic connections between inner hair cells and auditory nerve fibers and a loss of outer hair cells in the high-frequency region of the cochlea. Nonetheless, the cellular and molecular mechanisms underlying these age-related losses remain mostly unknown.”
“Outer hair cells are sensory cells implicated in the mechanical amplification of sounds and in the frequency selectivity in mammals,” they said.
“Outer hair cells respond to changes in membrane voltage with changes in length, a phenomenon known as electromotility, which is brought about by the motor protein prestin, a polytopic integral membrane protein present in the outer hair cell’s lateral wall.”
“The organization of the outer hair cell lateral wall is exclusive among hair cells and other mammalian cell types because it contains a tightly regulated level of cholesterol.”
“It has been postulated that alterations in the cholesterol content in the lateral wall might modulate the function and/or distribution of prestin within the plasma membrane.”
“We hypothesize that cholesterol deficiency might play a role in the associated cochlear pathologies that occur during aging. However, the role of cholesterol homeostasis in the physiopathology of the inner ear has not been studied.”
In the study, the researchers measured the levels of…
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