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Full-Text Articles in Physical Sciences and Mathematics
Multiphoton Response Of Retinal Rod Photoreceptors, Vasilios Alexiades, Harihar Khanal
Multiphoton Response Of Retinal Rod Photoreceptors, Vasilios Alexiades, Harihar Khanal
Publications
Phototransduction is the process by which light is converted into an electrical response in retinal photoreceptors. Rod photoreceptors contain a stack of (about 1000) disc membranes packed with photopigment rhodopsin molecules, which absorb the photons. We present computational experiments which show the profound effect on the response of the distances (how many discs apart) photons happen to be absorbed at. This photon-distribution effect alone can account for much of the observed variability in response.
Computational Models For Diffusion Of Second Messengers In Visual Transduction, Harihar Khanal
Computational Models For Diffusion Of Second Messengers In Visual Transduction, Harihar Khanal
Publications
The process of phototransduction, whereby light is converted into an electrical response in retinal rod and cone photoreceptors, involves, as a crucial step, the diffusion of cytoplasmic signaling molecules, termed second messengers. A barrier to mathematical and computational modeling is the complex geometry of the rod outer segment which contains about 1000 thin discs. Most current investigations on the subject assume a well-stirred bulk aqueous environment thereby avoiding such geometrical complexity. We present theoretical and computational spatio-temporal models for phototransduction in vertebrate rod photoreceptors, which are pointwise in nature and thus take into account the complex geometry of the …