Visual pigments of the tree shrew (Tupaia belangeri) and greater galago (Galago crassicaudatus): A microspectrophotometric investigation (original) (raw)

Cone structure and visual pigment content in the retina of the goldfish

Vision Research, 1976

Histologic examination of the retina in comet goldfish 11 cm long (nose to base of tail) reveals at least six distinct varieties of cones. Unequal double cones (DC) comprise long (LD) and short (SD) members which differ in form as well as length. Long single (LS) cones are similar in length and form to SD cones. Although evidence indicates that there are two subpopulations of LS cones, normally they are structurally indistinguishable. Short single (SS) cones have short, broad outer segments and ellipsoids and virtually no myoids. Miniature long single (MLS) cones have the same shape as LS cones, but they are shorter and more slender and their nuclei project farther into the outer nuclear layer. Miniature short single (MSS) cones have the same shape as SS cones, but they are shorter and more slender and their nuclei are found with those of MLS-cones. The average cone densities. relative to SS = 1.0. are: DC (oairs) a 2.0. LS (total) z 1.4-2.0, MSS z 0.4-0.8. and MLS < 0.1. The form dimensions. and deniities'of cones do 'not vary systematically with location in the retina.

Photosensitive and photostable pigments in the retinae of Old World monkeys

The Journal of experimental biology, 1991

Microspectrophotometric measurements of retinal receptors are reported for eight species of Old World monkey. Although the animals vary greatly in size, colourings and habitat, they all appear to be trichromats and the peak sensitivities of their cones invariably lie near 430, 535 and 565 nm. This consistent pattern contrasts with the results reported earlier for New World monkeys and with the results reported here for Tupaia glis. The trichromacy of frugivorous catarrhine monkeys may have co-evolved with a particular class of coloured fruit. Short-wave cones were rare in all species. The ratio of the numbers of middle-wave and long-wave cones varied between individual animals, but had an overall value close to unity. In the case of all the species examined here, we have recorded a photostable pigment in the inner segments of rods and cones. The latter pigment has a peak sensitivity close to 420 nm and an absorbance spectrum that is narrower than that of a photosensitive visual pigm...

Visual pigments and the labile scotopic visual system of fish

Vision Research, 1984

Among mammals, birds, most reptiles and chondrichthians, only rhodopsins are present. Among agnathans, osteichthians, amphibians and certain freshwater turtles there are species having only porphyropsins or only rhodopsins or, more interestingly, both pigments, either sequentially or together. This latter grouping represents the paired-pigment species. Associated with the presence of pairedpigments is the possibility that the proportions of rhodopsin and porphyropsin may change. Depending on the characteristics of each paired-pigment species, naturally occurring changes in visual pigment ratios are related to migrations in anadromous and catadromous teleosts and anadromous cyclostomes and to seasonal variation in several teleosts. In addition, the visual pigment composition of certain species of teleosts has been altered by the specific effects of light, temperature, diet and hormones. Of two possible mechanisms for altering spectral sensitivity, varying the proportion of rhodopsin and porphyropsin is far more common than utilizing a single chromophore and changing the opsin. In addition to the long established evidence that extractable rod pigment ratios may change during the life cycle or in response to specific exogenous factors, there is the more recent recognition from microspectrophotometry that cone pigment ratios may also change in concert. The effect of lighting conditions and temperature on the visual pigment composition of certain paired-pigment species is presented.

Annual Review of Vision Science The Retinal Basis of Vertebrate Color Vision

2019

The jawless fish that were ancestral to all living vertebrates had four spectral cone types that were probably served by chromatic-opponent retinal circuits. Subsequent evolution of photoreceptor spectral sensitivities is documented for many vertebrate lineages, giving insight into the ecological adaptation of color vision. Beyond the photoreceptors, retinal color processing is best understood in mammals, especially the blueON system,which opposes shortagainst long-wavelength receptor responses. For other vertebrates that often have three or four types of cone pigment, new findings from zebrafish are extending older work on teleost fish and reptiles to reveal rich color circuitry. Here, horizontal cells establish diverse and complex spectral responses even in photoreceptor outputs. Cone-selective connections to bipolar cells then set up color-opponent synaptic layers in the inner retina, which lead to a large variety of color-opponent channels for transmission to the brain via retin...

Visual pigments, cone oil droplets and ocular media in four species of estrildid finch

Journal of Comparative Physiology A, 2000

A microspectrophotometric study was conducted on the retinal photoreceptors of four species of bird: cut-throat ®nches (Amadina fasciata), gouldian ®nches (Erythrura gouldiae), white-headed munias (Lonchura maja) and plum-headed ®nches (Neochmia modesta). Spectral characteristics of the photoreceptors in all four species were very similar. Rods contained a medium-wavelength-sensitive visual pigment with a wavelength of maximum absorbance at 502±504 nm. Four spectrally distinct types of single cone contained a visual pigment with wavelength of maximum absorbance at either 370±373 nm (ultraviolet-sensitive), 440±447 nm (short-wavelength-sensitive); 500 nm (medium-wavelength-sensitive) or 562±565 nm (long-wavelength-sensitive). Oil droplets in the ultraviolet-sensitive single cones showed no detectable absorption between 330 nm and 800 nm. Oil droplets in the short-, medium-, and long-wavelength-sensitive single cones had cut-o wavelengths at 415±423 nm, 510±520 nm and 567± 575 nm, respectively. Double cones contained the visual pigment with wavelength of maximum absorbance at 562±565 nm observed in long-wavelength-sensitive single cones. Only the principal member of the double cone pair contained an oil droplet (P-type, cut-o wavelength at 414±489 nm depending on species and retinal location). Spectral transmittance of the intact ocular media of each species was measured along the optic axis. Wavelengths of 0.5 transmittance for all species were very similar (316±318 nm).

Evolution of Visual and Non-visual Pigments

Springer eBooks, 2014

The Springer Series in Vision Research is a comprehensive update and overview of cutting edge vision research, exploring, in depth, current breakthroughs at a conceptual level. It details the whole visual system, from molecular processes to anatomy, physiology, and behavior; and covers both invertebrate and vertebrate organisms from terrestrial and aquatic habitats. Each book in the Series is aimed at all individuals with interests in vision including advanced graduate students, post-doctoral researchers, established vision scientists and clinical investigators. The series editors are N.