Tikidji-Hamburyan2018 - Rod phototransduction under strong illumination

Tikidji-Hamburyan2018 - Rod phototransduction
under strong illumination

This model is described in the article:

Rods progressively escape
saturation to drive visual responses in daylight
conditions.

Tikidji-Hamburyan A, Reinhard K,
Storchi R, Dietter J, Seitter H, Davis KE, Idrees S, Mutter M,
Walmsley L, Bedford RA, Ueffing M, Ala-Laurila P, Brown TM, Lucas
RJ, Münch TA.
Nat Commun 2017 Nov; 8(1): 1813
Abstract:

Rod and cone photoreceptors support vision across large
light intensity ranges. Rods, active under dim illumination,
are thought to saturate at higher (photopic) irradiances. The
extent of rod saturation is not well defined; some studies
report rod activity well into the photopic range. Using
electrophysiological recordings from retina and dorsal lateral
geniculate nucleus of cone-deficient and visually intact mice,
we describe stimulus and physiological factors that influence
photopic rod-driven responses. We find that rod contrast
sensitivity is initially strongly reduced at high irradiances,
but progressively recovers to allow responses to moderate
contrast stimuli. Surprisingly, rods recover faster at higher
light levels. A model of rod phototransduction suggests that
phototransduction gain adjustments and bleaching adaptation
underlie rod recovery. Consistently, exogenous chromophore
reduces rod responses at bright background. Thus, bleaching
adaptation renders mouse rods responsive to modest contrast at
any irradiance. Paradoxically, raising irradiance across the
photopic range increases the robustness of rod responses.

This model is hosted on
BioModels Database
and identified by:
MODEL1710030000.
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
issue):D542-8.

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