Biology (B.S.B.)

Document Type and Release Option

Thesis (open access)

Faculty Mentor

Johanne Lewis


Sleep is a universal phenomenon in vertebrates and lack of sleep has been linked with various abnormal behaviors (Singh et al 2013). Studies have shown that a strong linkage exists between stress and sleep, or lack thereof. In fact, the Better Sleep Council’s 2009 survey revealed that 65% of Americans lose sleep due to elevated stress (Wells and Vaughn 2012). Continual (chronic) elevated stress levels have been linked with serious negative health effects. By using sleep deprivation studies, on a simpler animal model than humans it is our aim to investigate the consequences of sleep deprivation at the physiological and biochemical level in a teleost fish. The stress response in teleost fish has many similarities to that of other terrestrial vertebrates, including humans, so as well as being a simpler model the teleost fish also presents itself as a physiologically relevant model organism. In fish, corticosteroid production occurs via the same pathway as terrestrial vertebrates (called the brain-pituitary-adrenal axis). The increased production of blood corticosteroids in response to stress is one of the most evolutionary conserved organismal responses to stress (Aluru and Vijayan 2009). Chronic elevation of corticosteroids have been linked with increased blood sugar levels, elevated appetite, increased weight gain (due to increased storage of fats) as well as impairment of the immune response, digestive system, reproduction and growth (Wendelaar Bonga 1997). The main objective of our study is to determine if sleep deprivation will result in an increase in stress levels of the fish, which can be measured by changes in the circulating levels of cortisol (corticosteroid).