Amita Sehgal is a molecular biologist and chronobiologist in the Department of Neuroscience at the Perelman School of Medicine at the University of Pennsylvania.
[6] In 1988, she began her Postdoctoral Fellowship at Rockefeller University in the lab of Michael Young, where she had her first exposure to the study of circadian rhythms, a field in which she has since remained.
In 1994, Sehgal, Price, Man, and Young, through forward genetics, discovered a mutant of the gene timeless (TIM) in Drosophila melanogaster.
In 1996, Sehgal's laboratory showed that degradation in TIM levels caused by a pulse of light resets the circadian clock.
In 2001, Sehgal and her colleagues learned that some patients with Neurofibromatosis type 1 also experience irregularities in their sleep, and so decided to investigate the circadian rhythms of flies with a nonfunctional NF1 gene.
[12] In 2006, Sehgal and her colleagues discovered a mutant fly which takes an abnormally long time to adjust to new light-dark cycles.
This gene codes for an F-box protein called JET, a ubiquitin ligase that facilitates resetting the drosophila clock.
By using a steroid called RU-486 (Mifepristone) to regulate protein kinase A (PKA), they were able to upregulate and downregulate the expression of genes in specific areas like the mushroom bodies, and found that this structure is critical for fly sleep.
[15] While the specific pathway through which these mushroom bodies regulate sleep is currently unknown, it may be that they are involved in inhibiting processing of sensory information, allowing flies to fall asleep.