Mechanism of polarized light perception

Area of Science:

• * Vision science
• * Animal behavior
• * Cellular biology

Background:

• * Intraretinal sensitivity to polarized light is crucial for arthropods and cephalopods.
• * Previous hypotheses suggest ommatidia and retinular cells play key roles in detecting visual parameters like polarization.
• * The microvilli within rhabdomeres, containing photopigment molecules, are believed to be the site of light sensitivity and e-vector detection.

Purpose of the Study:

• * To investigate the mechanisms of intraretinal sensitivity to polarized light in decapod crustaceans.
• * To test the hypothesis of a two-channel polarization analyzer within ommatidia.
• * To provide experimental evidence for the role of microvillar orientation in e-vector detection.

Main Methods:

• * Review of existing facts and hypotheses on polarized light sensitivity in arthropods and cephalopods.
• * Selective adaptation experiments on the eyes of Cardisoma (decapod crustacean).
• * Analysis of spectrophotometric, fine-structural, electrophysiological, and behavioral data.

Main Results:

• * Experimental evidence supports a two-channel polarization analyzer in decapod crustaceans.
• * The functional units for polarization detection align with microvillar orientations in rhabdomeres.
• * These orientations correspond to the animal's normal spatial orientation (vertical and horizontal axes).

Conclusions:

• * A single ommatidium functions as a dual polarization analyzer, utilizing two subgroups of retinular cells.
• * The microvillar structure within rhabdomeres provides the cellular basis for e-vector orientation detection.
• * The proposed model effectively explains existing data on polarization vision across various arthropods and cephalopods.