Spectroscopic properties of porphyropsins

Bridges, C.D.B.

doi:10.1016/0042-6989(67)90044-2

Cited by 136 publications

(55 citation statements)

References 28 publications

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“…The base line value was subtracted from the absorbance curve value and the difference used to compute a normalized point-curve. The Am... was estimated by the method of Dartnall, Lander & Munz (1961) as amplified by Bridges (1967) and involved 10 separate estimates based on the Al nomogram of Dartnall (Wyszecki & Stiles, 1967, p. 584).…”

Section: Methodsmentioning

confidence: 99%

The visual pigments of rods and cones in the rhesus monkey, Macaca mulatta.

Bowmaker¹,

Dartnall²,

Lythgoe³

et al. 1978

The Journal of Physiology

109

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SUMMARY1. New microspectrophotometric measurements have been made of the photopigments of individual rods and cones from the retina of the rhesus monkey (Macaca mulatta). The measuring beam was passed transversely through isolated outer segments.2. The transverse absorbance for rods ranged from 0-02 to 0'04 and that for cones from 0.01 to 0'03.3. The mean absorbance spectrum for rods (n = 25) had a peak at 502 + 2*7 nm. A digitonin extract from the same group of eyes gave a Amax. of 499 + 1 nm.4. Of a sample of 82 cones, 40 were 'red' (P565 nm) and 42 were 'green' (P536 nm). The mean absorbance spectrum for the green cones is very similar to the Dartnall nomogram, but that for the red cones is narrower.5. No bleachable, blue-sensitive outer segments were recorded, although structures were found that absorbed at short wave-lengths and were neither photosensitive nor dichroic. 6. If the long wave-length and middle wave-length cone pigments of the rhesus monkey are assumed to be identical to those of man and if additional assumptions are made about the lengths of human outer segments and about prereceptoral absorption, it is possible to derive psychophysical sensitivities that closely resemble the 7rT and i4 mechanisms of W. S. Stiles.

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Section: Methodsmentioning

confidence: 99%

The visual pigments of rods and cones in the rhesus monkey, Macaca mulatta.

Bowmaker¹,

Dartnall²,

Lythgoe³

et al. 1978

The Journal of Physiology

109

View full text Add to dashboard Cite

show abstract

“…A rhodopsin with an absorption maximum at about 500 nm is the likely rod photopigment for most birds (Goldsmith 1990). Therefore, the sensitivity function under reduced illumination was normalized with the maximum at 500 nm= 100%, and compared with a rhodopsin absorption function extending into the UV (Bridges 1967;Fig. 7).…”

Section: Spectral Sensitivity Under Reduced Illuminationmentioning

confidence: 99%

Spectral sensitivities including the ultraviolet of the passeriform bird Leiothrix lutea

Maier

1992

J Comp Physiol A

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Summary.Spectral sensitivity functions of a passeriform bird, the Red-billed Leiothrix Leiothrix lutea (Timalidae) were determined in a behavioural test under different background illuminations.1. With photopic illumination the spectral sensitivity of Leiothrix lutea covered the measured range from 320 nm to 680 nm. Four peaks of spectral sensitivity were found: a UV (370 nm), a blue (460 nm), a green (530 nm) and a red (620 nm) sensitivity peak. The spectral sensitivity was highest in the UV and decreased (over the blue and the green peak) towards the red sensitivity peak. The 4 peaks of spectral sensitivity point to 4 underlying cone mechanisms under photopic illumination and thus to a probably tetrachromatic colour vision of Leiothrix lutea.2. With mesopic illumination the bird's spectral sensitivity covered the measured range from 320 nm to 680 nm. Neural interactions between cone and rod sensitivities are likely to determine this function. The increased overall sensitivity and a dominant sensitivity peak at 500 nm point to a typical rhodopsin as the likely rod photopigment.3. Different aspects of the biological significance of the high UV sensitivity are discussed.

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“…The ?. was estimated by the method of Dartnall, Lander & Munz (1961) as amplified by Bridges (1967) and involved ten separate estimates based on the A. nomogram of Dartnall (Wyszecki & Stiles, 1967, p. 584). The precision of this analytical method for rhodopsin, and the reproducibility of absorbance measurements by microspectrophotometry, have been shown previously (Bowmaker, Loew & Liebman, 1975).…”

Section: Methodsmentioning

confidence: 99%

Visual pigments of rods and cones in a human retina.

Bowmaker¹,

Dartnall²

1980

The Journal of Physiology

452

210

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SUMMARY1. Microspectrophotometric measurements have been made of the photopigments of individual rods and cones from the retina of a man. The measuring beam was passed transversely through the isolated outer segments.2. The mean absorbance spectrum for rods (n = 11) had a peak at 497-6 + 3-3 npm and the mean transverse absorbance was 0-035 + 0 007.3. Three classes of cones were identified. The long-wave cones ('red' cones) had a Amax of 562-8 + 4-7 nm (n = 19) with a mean transverse absorbance of 0-027 + 0 005. The middle-wave cones ('green' cones) had a AmaK of 533-8 + 3-7 nm (n = 11) with a mean transverse absorbance of 0*032 + 0 007. The short-wave cones ('blue' cones) had a Amax of 420-3 + 4-7 nm (n = 3) with a mean transverse absorbance of 0 037 + 0*011.4. If assumptions are made about the length of cones and about pre-receptoral absorption, it is possible to derive psychophysical sensitivities for the cones that closely resemble the appropriate 7T mechanisms of W. S. Stiles.5. If assumptions are made about the length of rods and about pre-receptoral absorption, however, the psychophysical sensitivity derived for the rods is considerably broader than the C.I.E. scotopic sensitivity function.

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Spectroscopic properties of porphyropsins

Cited by 136 publications

References 28 publications

The visual pigments of rods and cones in the rhesus monkey, Macaca mulatta.

The visual pigments of rods and cones in the rhesus monkey, Macaca mulatta.

Spectral sensitivities including the ultraviolet of the passeriform bird Leiothrix lutea

Visual pigments of rods and cones in a human retina.

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