Phototransduction in the Vertebrate Visual System
As part of the Mathematical Biology undergraduate training grant UBM at UMBC,
Prof. P. Robinson (Biology Department, UMBC) and I are mentoring
four undergraduate students Drew Thatcher, Kevin Herold, Abigail Jackson , Jessica Ortega on
modeling phototransduction in the vertebrate visual system. Previous students
J. Meisel and Kim Daniels that worked on this project are in graduate school at U. Penn and Harvard, respectively. Building
on modeling work on rhodopsin, a vertebrate opsin that has been
previously studied and modeled, we focus our research on melanopsin, a
unique vertebrate opsin discovered just ten years ago in light
sensitive ganglion cells in the vertebrate visual system. The goal of
our joint research project is to model the deactivation of the
phototransduction cascade that converts a photon of light to an
electrical signal that gets transmitted to the brain, via a chemical
cascade. Based on recent experimental results from the Robinson lab,
the deactivation of this chemical cascade accelerates in the presence
of over expressed beta-arrestin. We have developed a mathematical
model of this process that predicts this response. We used
experimental data of wild-type melanopsin to fit model parameters and
the resulting model successfully predicts experimental results where
beta-arrestin is over-expressed.
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