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A molecular basis for Weber's law

Published online by Cambridge University Press:  02 June 2009

Stevan M. Dawis
Stevan M. Dawis
Affiliation:
Laboratory of Biophysics, The Rockefeller University, New York
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Abstract

A mathematical model is presented that obeys a strong form of Weber's law – over a range of adapting and stimulus intensities, equal contrast stimuli evoke identical responses. To account for the strong Weber's law, the adaptive stage in the proposed model employs a “delayed” reverse reaction along with a power-law input. It is suggested that this Weber's law mechanism is responsible for a slow, voltage-uncorrelated component of adaptation in the vertebrate photoreceptor. A plausible biochemical mechanism is the G-protein cycle with phosphorylation of photoactivated photopigment (and binding of arrestin to the phosphorylated photopigment) as the adaptive process. In an Appendix, features of the general model and implications of a specific biochemical model are examined by computer simulation.

Keywords

Weber's lawTransductionAdaptationGuanine nucleotide binding protein (G-protein)Photoreceptor

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Type
Research Articles
Information
Visual Neuroscience , Volume 7 , Issue 4 , October 1991 , pp. 285 - 320
Copyright
Copyright © Cambridge University Press 1991

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