Vertebrate photoreceptors

Prog Retin Eye Res. 2001 Jan;20(1):49-94. doi: 10.1016/s1350-9462(00)00014-8.


The basis of the duplex theory of vision is examined in view of the dazzling array of data on visual pigment sequences and the pigments they form, on the microspectrophotometry measurements of single photoreceptor cells, on the kinds of photoreceptor cascade enzymes, and on the electrophysiological properties of photoreceptors. The implications of the existence of five distinct visual pigment families are explored, especially with regard to what pigments are in what types of photoreceptors, if there are different phototransduction enzymes associated with different types of photoreceptors, and if there are electrophysiological differences between different types of cones.

Publication types

  • Review

MeSH terms

  • Adaptation, Ocular
  • Amino Acid Sequence
  • Animals
  • Calcium / metabolism
  • Cyclic GMP / metabolism
  • Electrophysiology
  • Humans
  • Molecular Sequence Data
  • Photoreceptor Cells, Vertebrate* / classification
  • Photoreceptor Cells, Vertebrate* / cytology
  • Photoreceptor Cells, Vertebrate* / physiology
  • Retinal Pigments / chemistry
  • Retinal Pigments / physiology
  • Sequence Homology, Amino Acid
  • Vision, Ocular / physiology


  • Retinal Pigments
  • Cyclic GMP
  • Calcium