Vision invertebrate

Some details about cone cells and invertebrate vision... 

Some details about cone cells and invertebrate vision. The biochemistry of retinal cones is less well known but is similar to that of rod cells. Cone pigments are present in the plasma membrane rather than in isolated discs (Fig. 23-40C). Different a, P, and y subunits of transducin are formed in rods and cones.522 Many differences are seen among various invertebrate visual systems. Inositol triphosphate (IP3) and Ca2+ often serve as signals of photoexcitation. G proteins also play prominent roles.522... 

R. Menzel (1979). Spectral sensitivity and color vision in invertebrates. In H. Hutrum (Ed.), Comparative Physiology and Evolution in Invertebrates (pp. 503-580). Springer-Verlag, New York. 

Retinal (Figures 12.13 and 12.14) is roughly half of the P-carotene molecule (Figure 12.12). Most animals get vitamin A from leaves, while carnivores (meat eaters) get vitamin A from other animals. AU vertebrates (animals with a backbone) use retinal, while invertebrates use the hydroxylated forms of retinal. We are interested in the primary process of vision, which takes less than a millionth of the time for the whole process of seeing, that is, noticing and becoming aware of light. 

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