The circadian rhythm is a mechanism that allow organisms to synchronize their internal physiological systems to their external environment. Our brain has an internal biological clock that synchronizes other biological clocks in our bodies, such as in our heart, pancreas, fat tissue, kidney, and liver. In 2009, researchers in the Turek Lab discovered that mice fed a high-fat diet during the light phase (mice’s irregular feeding phase since mice are nocturnal) gain significantly more weight than mice fed a high-fat diet during the dark phase. However, the experiment only tested male mice. In 2015, researchers found no significant difference in weight gain between daytime-fed female mice and night-time fed female mice. My project aims to identify a cause for the difference in how male and female mice gain weight by testing the effect of estrogen. Estrogen is a hormone that reduces food intake and body adiposity while increasing energy expenditure. Previous research has shown that a decline in estrogen levels may be associated with irregular internal circadian rhythms. Furthermore, studies have shown that ovariectomies have shown an increase in body weight while estrogen treatment after an ovariectomy showed a decrease in body weight. To study the effect of estrogen, I will study the weight gain in normal female mice compared to ovariectomized female mice on different feeding times to see how estrogen and circadian timing of feeding affect weight gain together.
This blog will likely be a place for me to share experiences of working in a science lab for the first time, learning new procedures, and any other challenges that may come my way.