TESTING THE EFFECT OF SLEEP DEPRIVATION-INDUCED STRESS ON MITOCHONDRIAL FUNCTION IN ADULT ZEBRAFISH BRAIN**
Stress is a well-known cause of cognitive dysfunction; however, the cell signaling mechanisms underlying this phenomenon remain unclear. Here, we explored the biochemical effects of chronic disruption of zebrafish (Danio rerio) circadian rhythms. Zebrafish are a particularly useful animal model to use in this type of experiment due to their diurnal nature. Previously, our lab showed alterations in the AKT-GSK3β signaling pathway with chronic sleep alteration. AKT plays a role in neuronal growth, plasticity, and metabolism. AKT is activated when it becomes phosphorylated on Ser473 or Thr308 by insulin signaling, growth factors, and increased neuronal activity. AKT regulates GSK-3β activity via phosphorylation on Ser9. This is neurophysiologically important, because unregulated GSK-3β is associated with cell death, dysregulated metabolic function, impairment of mitochondrial transport, alteration of mitochondrial membrane permeability, neuro-mediocrity, neuroinflammation, and many psychiatric/mood disorders. Light exposure was used to control the circardian rhythms of our fishes, which were housed in tanks enclosed within separate, opaque boxes. The control box was maintained on a normal 14hr/10hr zebrafish light/dark cycle. To induce alteration of zebrafish circadian rhythms, the experimental-box lights were unpredictably altered to induce sleep deprivation. Following the four days of treatment, the zebrafish were anesthetized and decapitated. The optic tectum and telencephalon were removed and immediately homogenized in ice-cold mitochondrial isolation buffer. Samples were centrifuged and the mitochondria-enriched supernatant was drawn off and further centrifuged. Following the second spin, mitochondrial pellets were suspended in isolation buffer and stored at -80°C until needed for complex I activity assay. We hypothesized that changes in complex I activity would occur in mitochondria isolated from telencephalon and optic tectum as a result of sleep deprivation. Preliminary results indicate that mitochondrial activity, as measured by the complex I activity assay, is altered in adult zebrafish brain subjected to four days of unpredictable light cycles.
Georgia Southern University Faculty Research Seed Award to Keri Barksdale-Mans
McClanahan*, Austin Jakob; Marden*, Kelly Lee; Moore*, Nick S.; Mans, Robert A.; and Barksdale, Keri A.
"TESTING THE EFFECT OF SLEEP DEPRIVATION-INDUCED STRESS ON MITOCHONDRIAL FUNCTION IN ADULT ZEBRAFISH BRAIN**,"
Georgia Journal of Science, Vol. 78, No. 1, Article 34.
Available at: https://digitalcommons.gaacademy.org/gjs/vol78/iss1/34