Statistical test of linearity of photoreceptor transduction process: Limulus passes, others fail Journal Article

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Authors: Grzywacz, N. M.; Hillman, P.
Article Title: Statistical test of linearity of photoreceptor transduction process: Limulus passes, others fail
Abstract: We present the results of a theoretical analysis of a completely general linear chain model for transduction in photoreceptors from which we have derived a statistical test for the intrinsic linearity of the single-photon transduction process. By linearity we mean comprising first-order chemical reactions only. We show results of our own measurements in Limulus ventral photoreceptors that pass this linearity test, suggesting that the single-photon transduction in Limulus may be a simple chain of first-order biochemical reactions (plus possible diffusional processes). However, we also demonstrate that published data show the existence of strong nonlinearities in the single-photon responses of toad and perhaps also of locust. Such nonlinearities are not difficult to construct from existing biochemical notions (feedback, cooperativity), but all but one Kramer, L. (1975) Biophys. Struct. Mech. 1,239-257] of the published analytical models of the single-photon process have been linear. The test we have used is the distribution of "areas" (time integrals of conductance changes) of single-photon responses or "bumps." Reasonable molecular linear chain models do not allow distributions very sharply peaked at non-zero values. Such peaked distributions are seen in toad and locust but not in Limulus.
Journal Title: Proceedings of the National Academy of Sciences of the United States of America
Volume: 82
Issue: 1
ISSN: 0027-8424
Publisher: Unknown  
Date Published: 1985
Start Page: 232
End Page: 235
Language: eng
DOI/URL:

https://www.ncbi.nlm.nih.gov/pubmed/3855544

10.1073/pnas.82.1.232
Notes: undefined; J2: Proc Natl Acad Sci U S A