Thesis
Sleep behavior and oxidative stress resilience in surface- and cave-dwelling Astyanax mexicanus larvae
Agboola, L.O.
Record Number:
7121
Year:
2025
University:
Texas A and M University
Abstract:
Neurodegenerative diseases, including Parkinson's and Alzheimer's, are closely linked to oxidative stress, mitochondrial dysfunction, and disrupted sleep-wake cycles. Identifying natural models of resilience to such stressors can provide insight into therapeutic strategies. The Mexican tetra (Astyanax mexicanus), which exists as both surface- and cave-dwelling morphs, offers a unique evolutionary framework for investigating stress biology. Cavefish display traits often associated with human disease-such as insulin resistance, elevated ROS, and reduced sleep-yet remain physiologically robust, suggesting potential resilience mechanisms. This study examined the responses of surface and cavefish larvae to three experimentally induced stressors: rotenone (a mitochondrial complex I inhibitor), hydrogen peroxide (a ROS generator), and elevated temperature (a metabolic stressor). Behavioral tracking was used to monitor sleep over 24-hour cycles. Contrary to expectations, cavefish larvae were more sensitive than surface fish to rotenone and hydrogen peroxide, showing reduced health at higher concentrations. These findings suggest that cavefish may tolerate chronic oxidative conditions in nature but lack rapid detoxification mechanisms against acute, exogenous oxidative insults. Nevertheless, both morphs exhibited a conserved behavioral response to chemical stress: increased sleep during the light phase, which may serve as an energy-conserving or repair-promoting adaptation to oxidative damage. Temperature stress further distinguished between the two morphs: surface fish exhibited reduced sleep at elevated temperatures, whereas cavefish maintained stable sleep with a slight increase at 30 degrees C, reflecting thermal insensitivity and metabolic flexibility. Overall, A. mexicanus-particularly the cave-dwelling morph-provides a valuable model for dissecting natural mechanisms of stress tolerance, neurodegeneration, and sleep regulation with implications for aging and disease biology
Times Cited:
1
Relevent Species: