Reaction time of Aβ1–42 expressing nematode mutants to a specific auditory frequency may serve as a demonstrative surrogate of decreased neurodegeneration in dementia

Alzheimer’s Disease and other related disorders have steadily increased as the population ages. The conventional wisdom is that misfolding and accumulation of proteins such as Amyloid-β (Aβ) leads to neurodegeneration in these diseases. Available treatments are limited by marginal efficacy and side effects, raising the need to develop alternative therapies. The present study investigated the differing reactions of the nematode Caenorhabditis elegans mutant strain smg-1 CL2355, containing a human Aβ transgene engineered into its pan-neuronal cells, compared to its counterpart N2 wildtype control when exposed to different airborne auditory frequencies, contributing to the investigation of frequency treatment as a less expensive and non-invasive potential treatment for patients with dementia. The mutant strain smg-1 CL2355 contains a human Aβ transgene engineered into its pan-neuronal cells, resulting in an accumulation of Aβ plaques in its cerebral cortex, causing impairments in cognitive function. The smg-1, which exhibits deficits in thermotaxis memory (using the promoter of the C. elegans synaptobrevin ortholog (snb-1) to stimulate the pan-neuronal expression of Aβ1–42), was used as a model of neurodegeneration. This study observed the time for the organisms (N2 and smg-1 hermaphrodites) to react, in the form of backward sinusoidal locomotion, as well as the time taken for the organism to recover and return to the normal movement (forward-moving sinusoidal undulations), when exposed to the frequency spectrum (2s; 100Hz, 450Hz, 1-5kHz; 80dB SPL). The N2 wildtype strain reacted faster than the smg-1 across all frequencies except those at 4000Hz, where the smg-1 reacted and recovered faster than the N2 strain. The finding that exposure to a specific frequency may prevent neurodegeneration in this mutant nematode model may have implications for using auditory stimuli for treating dementia.