The Colour Change of the Minnow (Phoxinus Laevis AG.)

1951 ◽  
Vol 28 (3) ◽  
pp. 298-319
Author(s):  
E. G. HEALEY
Keyword(s):  
Spinal Cord ◽  
Colour Change ◽  
White Background ◽  
Time Intervals ◽  
Black Background ◽  
Colour Changes ◽  
The Times

1. Records were made of the times required for the melanophores of the normal minnow to reach equilibrium when the fish is transferred from one to another of the following conditions: on an illuminated white background; on an illuminated black background; in darkness. 2. These times give further evidence of the parts played by nervous and hormonal mechanisms in the colour change of the minnow. 3. After section of the spinal cord between the 5th and the 12th vertebrae the fish darkens but gradually becomes pale again if kept on an illuminated white background. 4. Such fish can still show a slow colour change: dark on a black background, pale on a white background and intermediate in darkness. 5. Observations of the times required for these colour changes in the spinal minnow show that these no longer resemble those associated with the unoperated fish; rather, they resemble the time intervals associated with amphibian colour change. 6. Further consideration of the times required for colour change in the spinal minnow indicate that there is not only a hormone causing aggregation of the melanophores but also a hormone causing melanophore dispersion. 7. The part played by double innervation of the melanophores is considered.

The Colour Change of the Minnow (PHOXINUS LAEVIS AG.)

1954 ◽  
Vol 31 (4) ◽  
pp. 473-490
Author(s):  
E. G. HEALEY
Keyword(s):  
Statistical Treatment ◽  
Colour Change ◽  
Spinal Nerve ◽  
White Background ◽  
Nerve Fibres ◽  
Degree Of Dispersion ◽  
Colour Changes ◽  
Spinal Section ◽  
The Times ◽  
Different Levels

1. Minnows were subjected to spinal section at different levels between vertebrae 4 and 15, and the degree of dispersion of all the main melanophore regions was recorded in terms of the melanophore index. 2. Records were made of the times required to reach equilibrium (a) when the fish were placed after the operation on a black or white illuminated background, and (b) when the fish at equilibrium on a black or white background were subjected to background reversal. 3. These records show that the times necessary for the melanophores to reach equilibrium on a given background are of the same order at all the vertebral levels investigated. 4. There is considerable variation in the degree of dispersion of similar melanophore regions of different individuals under the same conditions of operation and background. The nature of these individual differences is not known. 5. Apart from the possibility of incomplete section of chromatic nerve fibres near the 15th vertebra, there appears to be no correlation between the chromatic behaviour and the level of the operation; i.e. there is no indication that any activity of the spinal paling centre is being affected by spinal section at the different levels. 6. The results of experiments involving the elimination of the spinal paling centre were tested statistically. Within the limits of this treatment, based upon the melanophore index, it was concluded that the spinal paling centre plays no part in these colour changes. 7. Spinal section was carried out anterior to the 1st spinal nerve in order to interrupt the path of von Gelei's dispersing fibres. Statistical treatment of the results indicates that these fibres are playing no part in these colour changes. 8. Experiments involving combined spinal and autonomic section confirm the conclusions given in paragraphs 6 and 7. 9. Since no activity of the nervous system arising from the spinal paling centre or resulting from the background through von Gelei's dispersing fibres appears to be involved, the colour changes of these spinal minnows in response to illuminated backgrounds must be controlled by hormones alone. 10. In these spinal fish the various melanophore regions do not all react equally in terms of the melanophore index. Thus, those of the lateral stripe and associated dark pattern tend to have relatively higher M.I. values under all conditions.

scholarly journals The chromatic behaviour of the eel ( Anguilla vulgaris L.)

1940 ◽  
Vol 128 (852) ◽  
pp. 343-353 ◽  
Keyword(s):  
Blood Supply ◽  
White Background ◽  
Posterior Lobe ◽  
Pituitary Extract ◽  
Present Communication ◽  
Nervous Stimulation ◽  
Black Background ◽  
The Times ◽  
Stimulation Of

Neil (1939) has described the chromatic response of normal and blinded eels to various condition of illumination. From the times taken to equilibrate when passing from white to black “background” and vice versa with overhead illumination, he concluded that co-ordination is humoral. The time taken to equilibrate after transference to darkness from an illuminated white background or vice versa implies that control is bihumoral. Apart form Neill's work and an early comment by Petersen the chromatic behaviour of the eel has engaged little attention. Lode (1890) described contraction of the melanophores after faradic stimulation of the cord. Odiorne (1933) found that injection of posterior lobe pituitary extract caused expansion of the melanophores. The present communication deals with experiments designed to elucidate the mechanism of co-ordination more fully. It includes observations on ( a ) modification of normal chromatic behaviour by total or partial hypophysectomy; ( b ) effect of total and partial hypophysectomy on tolerance to pituitary extracts; ( c ) influence of nervous stimulation in the presence or absence of an intact blood supply. They are based chiefly on the behaviour of the dermal melanophores for recording which the melanophore index ( μ ) of Hogben and Slome (1931) is used throughout.

scholarly journals The pigmentary effector system - IX. The receptor fields of the teleostean visual response

1940 ◽  
Vol 128 (852) ◽  
pp. 317-342 ◽  
Keyword(s):  
Colour Change ◽  
Primary Response ◽  
Senior Author ◽  
The Other ◽  
White Background ◽  
Visual Response ◽  
Local Response ◽  
Black Background ◽  
Effector System ◽  
The Difference

Both among vertebrates and among Crustacea one commonly meets with two co-existent modes of chromatic response to photic stimulation. One is the dispersion (“expansion”) of melanophores and certain other chromatophores under the local (primary) influence of light on the skin. The other is aggregation (“contraction”) of melanophores and of certain other chromatophores when light reflected from the surroundings impinges on the organs of vision, in contradistinction to dispersion (“expansion”) when only overhead illumination strikes the eye. Though the primary (local) response is usually subordinate to and is more or less overruled by the secondary or visual response, the relative importance of the two components varies within wide limits. In particular species either may be negligible in comparison with the other. When, as more commonly, both contribute significantly to the observed result, a blinded animal is necessarily more pale in darkness than in light. Probably this fact influenced all the earlier investigators who, including the senior author (1924), paid little attention to the otherwise paradoxical fact that animals kept on a “black background” (i. e. under conditions of overhead illumination in light absorbing surroundings) are much darker than animals kept in similar conditions with no light at all. Subsequent analysis of the normal course of colour change, both in vertebrates and in Crustaces, has shown that this is also true of species which have no appreciable primary response, and that the difference generally exceeds the limits of variation consistent with the co-existence of a detectable primary response. It is therefore clear that the difference between the “white background” response and the “black background” response is not due to intensity alone.

scholarly journals Melanophore metachrosis response in amphibian tadpoles: effect of background colour, light and temperature

2020 ◽  
Vol 42 (1) ◽  
pp. 133-140
Author(s):  
Eduardo José Rodríguez-Rodríguez ◽  
Juan Francisco Beltrán ◽  
Rafael Márquez
Keyword(s):  
Environmental Factors ◽  
Physiological Response ◽  
Color Change ◽  
Colour Change ◽  
White Background ◽  
Behavioral Selection ◽  
Black And White ◽  
Black Background ◽  
Biochemical Mechanisms ◽  
Selection Of

Abstract The developmental and biochemical mechanisms of colour change through chromatophore metachrosis in amphibian tadpoles are relatively well studied, but the environmental factors driving colour change remain unclear. A cryptic response to background colour in order to reduce predation is an intuitively valid explanation, however, other hypotheses need to be explored. In this study, we aimed to investigate the environmental factors driving the melanophore metachrosis process in Alytes dickhilleni tadpoles. First, we tested the response to two backgrounds with clearly distinct reflectance: black and white. The proportion of dark tadpoles became significantly higher when they were located on the black background, and pale tadpole proportion was dominant on the white background, as expected from the crypsis hypothesis. Secondly, we added two new factors, temperature and photoperiod, maintaining the background variation. Our results suggest that lower temperatures, and short photoperiods were significantly driving a change to dark colouration in tadpoles, possibly allowing a more efficient thermoregulation, and in consequence, development and growth. Next we tested whether dark and pale tadpoles selected backgrounds that matched their colouration (black and white background), and found no evidence for behavioral selection. The apparent response in colour change to background appears to be mediated by the background reflectance of light, that there does not seem to be behavioral selection of matching background by the tadpoles, and therefore it suggests that color change is more likely to be a physiological response with thermoregulatory implications.

The Eye and Colour Change in the Minnow (Phoxinus Phoxinus L)

1972 ◽  
Vol 57 (3) ◽  
pp. 701-707
Author(s):  
MICHAEL J. GENTLE
Keyword(s):  
Colour Change ◽  
White Background ◽  
Surgical Removal ◽  
Phoxinus Phoxinus ◽  
Black Background ◽  
Temporal Field ◽  
Dorsal Retina

1. Counts were made of the retinal receptors and observations were made of the colour of the minnow, Phoxinus phoxinus L., following the surgical removal of parts of the dorsal and ventral retina. 2. It was found that there were greater numbers of retinal receptors in the temporal field than in the rostral field of the eye. 3. There were very few triple and quadruple cones but a large number of double and single cones in the ventral retina compared to the dorsal. 4. Surgical removal of the dorsal retina or only part of it resulted in the fish being fully dark-adapted on a black or white background. 5. Surgical removal of the ventral retina resulted in the fish assuming an intermediate colour on a white background and a darker tint on a black background.

Experimental evidence for the regeneration of nerve fibres controlling colour changes after anterior spinal section in the minnow ( Phoxinux Phoxinus L)

1967 ◽  
Vol 168 (1010) ◽  
pp. 57-81 ◽  
Keyword(s):  
Colour Change ◽  
Hormonal Control ◽  
Whole Body ◽  
White Background ◽  
Nerve Fibres ◽  
Nervous Control ◽  
Colour Changes ◽  
Spinal Section ◽  
Final Degree ◽  
Degree Of Recovery

A method for quantitative recording of the general tint of the skin of the minnow is described. Using this method, the colour changes in response to black/white background reversal of normal and of equilibrated chromatically spinally operated minnows, previously black- or white-adapted for more than 9 months, were plotted to give standard curves. These enabled a clear distinction to be made between the rapid colour changes of the normal minnow with intact chromatic nervous system and the relatively very slow changes, only under hormonal control, of the chromatically spinally operated fish. Twenty minnows that had been white-adapted for more than 9 months and 19 that had been black-adapted for the same time were subjected to chromatic spinal section and replaced on the same backgrounds. At intervals their colour changes were recorded and plots of these records were compared with the standard curves. In the course of about 10 months 11 of these minnows showed a good recovery of rapid colour change, 9 showed medium recovery, 8 showed poor recovery and 11 continued to change colour at a rate typical of hormonal control. After another 9 months there was generally no further improvement. This varying degree of recovery of rapid colour change appears to have been the result of regeneration of chromatic fibres in the spinal cord, since a second section anterior to the level of the first and made 19 months after it was followed by darkening of the whole animal. Later it was able to change colour again in response to background reversal but these colour changes were of the slow hormonal type. Observations that recovery of nervously controlled colour change improved with time until some steady condition was reached and that there was great variation in this final degree of nervous control suggest that a number of chromatic fibres may run in the cord. Further,since the colour and pattern produced by the melanophores were affected equally over the whole body as the recovery of rapid colour change proceeded, it appears possible that each chromatic nerve fibre in the cord contributes to the state of excitation of a postganglionic system which is common to all the melanophores in the skin. Records of colour changes at certain stages during regeneration in the cord indicate that there was recovery of nervous control in one direction, i.e. for paling or darkening, while the change in the other direction was still only hormonal. Such observations suggest, in addition to the familiar concept of a nervous aggregating system, the existence of an active pigment-dispersing nervous mechanism.

METABOLIC STUDIES WITH 131I-LABELED THYROXINE. II.

1963 ◽  
Vol 44 (3) ◽  
pp. 475-480 ◽  
Author(s):  
R. Grinberg
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Optic Nerve ◽  
Pituitary Gland ◽  
Time Interval ◽  
Time Intervals ◽  
Pituitary Glands ◽  
The Central Nervous System ◽  
Tentative Explanation

ABSTRACT Radiologically thyroidectomized female Swiss mice were injected intraperitoneally with 131I-labeled thyroxine (T4*), and were studied at time intervals of 30 minutes and 4, 28, 48 and 72 hours after injection, 10 mice for each time interval. The organs of the central nervous system and the pituitary glands were chromatographed, and likewise serum from the same animal. The chromatographic studies revealed a compound with the same mobility as 131I-labeled triiodothyronine in the organs of the CNS and in the pituitary gland, but this compound was not present in the serum. In most of the chromatographic studies, the peaks for I, T4 and T3 coincided with those for the standards. In several instances, however, such an exact coincidence was lacking. A tentative explanation for the presence of T3* in the pituitary gland following the injection of T4* is a deiodinating system in the pituitary gland or else the capacity of the pituitary gland to concentrate T3* formed in other organs. The presence of T3* is apparently a characteristic of most of the CNS (brain, midbrain, medulla and spinal cord); but in the case of the optic nerve, the compound is not present under the conditions of this study.

scholarly journals Alteration of Tissue Marking Dyes Depends on Used Chromogen during Immunohistochemistry

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 835
Author(s):  
Selina Kiefer ◽  
Julia Huber ◽  
Hannah Füllgraf ◽  
Kristin Sörensen ◽  
Agnes Csanadi ◽  
...  
Keyword(s):  
Colour Change ◽  
Residual Tumour ◽  
Blue Colour ◽  
Close Margin ◽  
Correct Orientation ◽  
Therapeutic Regime ◽  
Colour Changes ◽  
Tissue Specimens ◽  
Immunohistochemical Analyses ◽  
Colour Signal

Pathological biopsy protocols require tissue marking dye (TMD) for orientation. In some cases (e.g., close margin), additional immunohistochemical analyses can be necessary. Therefore, the correlation between the applied TMD during macroscopy and the examined TMD during microscopy is crucial for the correct orientation, the residual tumour status and the subsequent therapeutic regime. In this context, our group observed colour changes during routine immunohistochemistry. Tissue specimens were marked with various TMD and processed by two different methods. TMD (blue, red, black, yellow and green) obtained from three different providers (A, B and C, and Whiteout/Tipp-Ex®) were used. Immunohistochemistry was performed manually via stepwise omission of reagents to identify the colour changing mechanism. Blue colour from provider A changed during immunohistochemistry into black, when 3,3′-Diaminobenzidine-tetrahydrochloride-dihydrate (DAB) and H2O2 was applied as an immunoperoxidase-based terminal colour signal. No other applied reagents, nor tissue texture or processing showed any influence on the colour. The remaining colours from provider A and the other colours did not show any changes during immunohistochemistry. Our results demonstrate an interesting and important pitfall in routine immunohistochemistry-based diagnostics that pathologists should be aware of. Furthermore, the chemical rationale behind the observed misleading colour change is discussed.

scholarly journals Indicator Layers Based on Ethylene-Vinyl Acetate Copolymer (EVA) and Dicyanovinyl Azobenzene Dyes for Fast and Selective Evaluation of Vaporous Biogenic Amines

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4361
Author(s):  
Tinkara Mastnak ◽  
Aleksandra Lobnik ◽  
Gerhard Mohr ◽  
Matjaž Finšgar
Keyword(s):  
Biogenic Amines ◽  
Vinyl Acetate ◽  
Colour Change ◽  
Ethylene Vinyl Acetate ◽  
Yellow Orange ◽  
Colour Changes ◽  
Limit Sensitivity ◽  
Linear Concentration Range ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

The article presents naked-eye methods for fast, sensitive, and selective detection of isopentylamine and cadaverine vapours based on 4-N,N-dioctylamino-4′-dicyanovinylazobenzene (CR-528) and 4-N,N-dioctylamino-2′-nitro-4′-dicyanovinylazobenzene (CR-555) dyes immobilized in ethylene-vinyl acetate copolymer (EVA). The reaction of CR-528/EVA and CR-555/EVA indicator layers with isopentylamine vapours caused a vivid colour change from pink/purple to yellow/orange-yellow. Additionally, CR-555/EVA showed colour changes upon exposure to cadaverine. The colour changes were analysed by ultraviolet–visible (UV/VIS) molecular absorption spectroscopy for amine quantification, and the method was partially validated for the detection limit, sensitivity, and linear concentration range. The lowest detection limits were reached with CR-555/EVA indicator layers (0.41 ppm for isopentylamine and 1.80 ppm for cadaverine). The indicator layers based on EVA and dicyanovinyl azobenzene dyes complement the existing library of colorimetric probes for the detection of biogenic amines and show great potential for food quality control.

scholarly journals Influence of Natural and Artificial Weathering on the Colour Change of Different Wood and Wood-Based Materials

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 488 ◽  
Author(s):  
Davor Kržišnik ◽  
Boštjan Lesar ◽  
Nejc Thaler ◽  
Miha Humar
Keyword(s):  
Laboratory Test ◽  
Colour Change ◽  
Natural Weathering ◽  
Blue Staining ◽  
Artificial Weathering ◽  
Blue Stain Fungi ◽  
Colour Changes ◽  
Blue Stain ◽  
Positive Correlations ◽  
The Aesthetic

The importance of the aesthetic performance of wood is increasing and the colour is one of the most important parameters of aesthetics, hence the colour stability of twelve different wood-based materials was evaluated by several in-service and laboratory tests. The wood used for wooden façades and decking belongs to a group of severely exposed surfaces. Discolouration of wood in such applications is a long-known phenomenon, which is a result of different biotic and abiotic causes. The ongoing in-service trial started in October 2013, whilst a laboratory test mimicking seasonal exposure was performed in parallel. Samples were exposed to blue stain fungi (Aureobasidium pullulans and Dothichiza pithyophila) in a laboratory test according to the EN 152 procedure. Afterwards, the same samples were artificially weathered and re-exposed to the same blue stain fungi for the second time. The purpose of this experiment was to investigate the synergistic effect of weathering and staining. The broader aim of the study was to determine the correlation factors between artificial and natural weathering and to compare laboratory and field test data of fungal disfigurement of various bio-based materials. During the four years of exposure, the most prominent colour changes were determined on decking. Respective changes on the façade elements were significantly less prominent, being the lest evident on the south and east façade. The results showed that there are positive correlations between natural weathering and the combination of artificial weathering and blue staining. Hence, the artificial weathering of wood-based materials in the laboratory should consist of two steps, blue staining and artificial weathering, in order to simulate colour changes.

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