title: Range of modulation of light sensitivity by accessory pigments in the crayfish compound eye.
abstract: The compound eye of the crayfish during dark adaptation undergoes an enhancement of light sensitivity within a range of 3 log units. Only 1 log unit can be explained by the increase in responsiveness of the retinula cells. The rest can be accounted for by the migration of the proximal and distal accessory pigments. In isolated retinas, with the distal pigment paralysed in light-adapted position and the proximal pigment only partially responsive, the sensitivity enhancement in darkness is reduced in more than 1 log unit. By hormonally inducing the expansion of the distal pigment while the rest of the system remains dark-adapted, there is a shift of one log unit in the V-log 1 curve. In a crayfish mutant devoid of the two dark accessory pigments, the sensitivity enhancement in dark adaptation only covers one log unit.
mesh_terms: D000818:Animals; D003400:Astacoidea / Q000502:physiology*; D003623:Dark Adaptation; D004596:Electroretinography; D005260:Female; D066298:In Vitro Techniques; D008027:Light; D008297:Male; D010786:Photoreceptor Cells / Q000502:physiology; D012160:Retina / Q000502:physiology; D012168:Retinal Pigments / Q000502:physiology*; D013997:Time Factors
chemical_list: D012168:Retinal Pigments