Student Research - Neuroscience
Herberth Balsells H.
The Neuronal Basis of Circadian Rhythms: Developing a Model System
Abstract: There is evidence that the lateral ventral neurons (LVN) in the brain of Drosophila represent the fruit fly's internal clock. An internal clock would be expected to have physiological activity (an output) in the absence of input from the external environment or other neurons. However, the clock may be reset or synchronized with external cues, such as the day-night cycle. In order to test that the LVN region of the brain controls the daily rhythms of the fruit fly, we are using transgenic approaches to express different genes in the LVN, using a promoter for the timeless protein, which will drive gene expression only in cells with circadian activity. First, we have introduced to the LVN neurons, a gene that encodes for jellyfish green fluorescence protein (GFP), which emits low energy green light, when it is exposed to blue light. In this way, we can use a fluorescent microscope to identify the green LVN neurons within the mass of brain tissue. Second, we have introduced to LVN, the gene that encodes for the MJD protein which causes Machado-Joseph Disease, also known as spinocerebellar ataxia type 3. MJD is a human neurodegenerative disease caused by a glutamine-repeat expansion in the MJD protein. We will test the hypothesis that the daily rhythms of motor behavior of the flies will be altered by expression of disease-causing MJD (containing 84 glutamine repetitions) but not the non-toxic MJD protein (only 27 glutamine repetitions). Our long-term goal is to use a combined behavioral and physiological approach to understand the function of the LVN.
Click here for Herberth's poster.
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