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Updated: May 9, 2026
14:35
Single-cell Suction Recordings from Mouse Cone Photoreceptors
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SAD and the not-so-single photoreceptors
The American Journal of Psychiatry
|August 10, 2013
Summary
Light influences human behavior and mood, with light therapy effective for Seasonal Affective Disorder (SAD). This review explores photoreceptors and a novel humoral phototransduction model involving blood pigments and gasotransmitters for light
Area of Science:
- Physiology
- Neuroscience
- Biochemistry
Background:
- Light significantly impacts animal physiology and human behavior.
- Seasonal Affective Disorder (SAD) is a mood disorder influenced by light exposure.
- Current understanding of light's molecular mechanisms in humans is incomplete.
Purpose of the Study:
- To review the roles of various photoreceptors in light's physiological effects.
- To present a theoretical model of humoral phototransduction.
- To explore potential therapeutic applications for light-related disorders.
Main Methods:
- Review of existing research on photoreceptors (rods, cones, melanopsin cells).
- Discussion of an evolutionary-based theoretical model of humoral phototransduction.
- Analysis of recent animal model data supporting the proposed model.
Main Results:
- Evidence supports the involvement of rod, cone, and melanopsin photoreceptors.
- A theoretical model proposes blood-borne tetrapyrrole pigments (hemoglobin, bilirubin) as photoreceptors.
- This model suggests light regulates gasotransmitters (e.g., carbon monoxide) via humoral phototransduction.
Conclusions:
- Understanding light's molecular mechanisms is crucial for treating SAD.
- The humoral phototransduction model offers a new perspective on light's physiological effects.
- Further research into these mechanisms may lead to novel therapies for circadian and circannual regulation disorders.
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