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Determination of Photoreceptor Cell Spectral Sensitivity in an Insect Model from In Vivo Intracellular Recordings
Published on: February 26, 2016
The gecko visual pigment: the anion hypsochromic effect.
1Department of Biology, University of California, Los Angeles 90024.
Vision Research
|January 1, 1991
Summary
The Tokay gecko's retinal 521-pigment spectral shifts are influenced by specific anions. Anions alter opsin conformation, affecting the pigment's photosensitivity through excited-state properties.
Area of Science:
- Biochemistry
- Molecular Biology
- Vision Science
Background:
- The 521-pigment in the Tokay gecko (Gekko gekko) retina is crucial for visual perception.
- Understanding how environmental factors influence pigment function is key to vision research.
Purpose of the Study:
- To investigate the spectral response of the 521-pigment to various anions.
- To elucidate the relationship between anion-induced spectral shifts and opsin conformation.
Main Methods:
- Solubilization of the 521-pigment in a chloride-deficient state.
- Addition of different classes of anions (Class I, II, III) to observe spectral changes.
- Analysis of absorption spectra to determine bathochromic and hypsochromic shifts.
Main Results:
- Class I anions (Cl-, Br-) induced a bathochromic shift.
- Class II anions (e.g., NO3-, N3-) caused a hypsochromic shift.
- Cations had no observable effect; Class I anions counteracted Class II effects.
Conclusions:
- Spectral shifts indicate changes in opsin conformation and the retinal chromophore's environment.
- Pigment photosensitivity is modulated by excited-state properties, influenced by anion interactions.
- The findings suggest a mechanism for visual adaptation based on anion-specific pigment modulation.
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