scholarly journals The Pigmentary Effector System IV.--A Further Contribution to the Role of Pituitary Secretion in Amphibian Colour Response

1924 ◽  
Vol 1 (2) ◽  
pp. 249-270
Author(s):  
LANCELOT T. HOGBEN
Keyword(s):  
Colour Change ◽  
Complete Removal ◽  
Posterior Lobe ◽  
Pituitary Extract ◽  
Nervous Control ◽  
Normal Individuals ◽  
Effector System ◽  
Physiologically Active Substances ◽  
Normal Colour ◽  
Pituitary Secretion

1. The contracted melanophores of both Anura (frogs and toads) and Urodela (salamanders) react by maximal expansion to pituitary extract; the active substance in the latter does not appear to be confined invariably to the posterior lobe of the mammalian gland. A positive melanophore response was obtained from the gland of a human abortus in the fourth month. 2. The removal of the whole pituitary gland may be accomplished in Urodele larvaæ (Amblystoma tigrinum) at any age (nine months to four years) without impairing their viability. After complete removal of the pituitary in Urodele larvæ, as in adult and larval Anura, the melanophores remain contracted and a state of permanent pallor ensues. The normal colour resulting from melanophore expansion can be re-established by injection of pituitary extract; but such animals regain pallor, although exposed to conditions in which melanophore expansion invariably occurs in normal individuals. 3. It is legitimate to conclude that pituitary secretion is the main factor in regulating the chromatic function throughout the Amphibia as a class. Fluctuating pituitary secretion in correlation with those conditions that evoke colour response in the frog (cf. the third paper of this series) provides a satisfactory basis for the interpretation of all the accredited bionomic data concerning colour response in adult Amphibia. Possibly adrenal secretion or some auxiliary mechanism plays a subsidiary part; but there are no satisfactory grounds for believing that nervous agencies directly influence amphibian melanophores; and there is reason to believe that even if amphibian melanophores are directly innervated, nervous control is not significant to the normal rhythm of colour change. 4. The study of amphibian colour response provides evidence not only of the presence of physiologically active substances in the pituitary, but functional activity of the gland in the intact animal. It does not appear, however, that the interpretation of colour response here put forward for Amphibia can be extended to Reptiles and Fishes.

The Central Nervous Control of Colour Change in the Minnow (Phoxinus Phoxinus L.)

1971 ◽  
Vol 54 (1) ◽  
pp. 83-91
Author(s):  
MICHAEL J. GENTLE
Keyword(s):  
Optic Nerve ◽  
Optic Tectum ◽  
Posterior Part ◽  
Colour Change ◽  
Complete Removal ◽  
The Other ◽  
Nervous Control ◽  
Phoxinus Phoxinus ◽  
External Conditions

1. The colour of the minnow Phoxinus phoxinus L. and its ability to undergo colour change were studied after partial and complete blinding. The blinding was accomplished either by section of the optic nerve or by tectal ablation. 2. Following bilateral section of the optic nerve the blinded minnows darken. After the initial darkening, half of the fish pale and the other half remain dark. 3. The colour of the fish blinded by bilateral section of the optic nerve could not be affected by external conditions. 4. Following complete removal of the optic tectum the fish at first paled, but after 24 h they darkened to very variable tints. 5. Unilateral section of the optic nerve coupled with unilateral tectal removal on the same or opposite side did not affect the ability of the fish to change colour. 6. The bilateral removal of the anterior tectum from a blinded darkened fish did not affect its colour. 7. The bilateral removal of the posterior tectum of a darkened fish caused maximal pallor. 8. By a series of lesions an area in the dorsal posterior part of the optic tectum was found to cause darkening in the blinded fish because following its removal the fish paled. 9. It is suggested that the fibres from the tectum may act by exciting or inhibiting the neurones of the paling centre in the anterior medulla.

scholarly journals The Photoreceptors of Lampreys

1935 ◽  
Vol 12 (3) ◽  
pp. 254-270
Author(s):  
J. Z. YOUNG
Keyword(s):  
Colour Change ◽  
Diurnal Changes ◽  
Posterior Pituitary ◽  
Nervous Control ◽  
Pineal Complex ◽  
Artificial Illumination ◽  
Pituitary Secretion ◽  
Set Up ◽  
The Brain ◽  
Illumination Removal

1. Illumination of the dorsal region of the head of an ammocoete larva is followed by movements of the animal, but only after exposure for longer periods than are necessary to elicit responses from the tail. 2. Since this reaction persists unaffected after removal of the pineal and paired eyes, it is concluded that it is produced by the direct effect of light on some tissue in the brain. 3. Larval and adult L. planeri show very pronounced daily rhythms of colour change, becoming pale at night and dark during the daytime. 4. Continuous artificial illumination of the animals produces maximal darkening and stops the diurnal rhythm. 5. When animals are left in total darkness the diurnal changes usually persist, though diminished in extent; sometimes the melanophores come to rest in the expanded phase. 6. Since section or faradic stimulation of spinal nerves is not followed by local changes in the melanophores, it is concluded that these are not under nervous control. 7. After removal of either the whole pituitary complex or its pars nervosa and intermedia the animals become maximally pale, and remain so indefinitely in spite of changes of illumination. 8. Injection of extracts of mammalian posterior pituitary lobe causes darkening of such hypophysectomised lampreys. 9. Pituitrin was also found to be capable of maintaining the expansion of isolated melanophores. 10. After removal of the pineal complex from ammocoetes the rhythms of colour change were interrupted, the melanophores remaining in the expanded phase under all conditions of illumination. Removal of the pineal of adult L. planeri disturbed the colour rhythm, which was then completely abolished if the paired eyes were also removed. 11. Thus the paling of an ammocoete when it passes from light to darkness is probably due to the inhibition of posterior pituitary secretion by nervous impulses set up by the change of illumination of the pineal complex.

scholarly journals The pigmentary effector system.—II

1922 ◽  
Vol 94 (658) ◽  
pp. 151-162 ◽  
Keyword(s):  
Drug Administration ◽  
Sensory Nerve ◽  
Colour Change ◽  
Direct Methods ◽  
Posterior Lobe ◽  
Excitatory Effect ◽  
Motor Paralysis ◽  
Effector System ◽  
Colour Changes ◽  
Direct Experiment

In a previous paper dealing with the pigmentary response evoked by pituitary (posterior lobe) administration in the common frog, emphasis has been laid on the necessity of discriminating between the alternatives of nervous and endocrine factors in controlling colour changes in Amphibia. In the present communication some account of the pigmentary responses evoked by physiological reagents is discussed, before passing on to more direct methods of experiment. To investigate the action of drugs on melanophores, the ideal method would be to study the effects of the latter on the isolated skin. In common with other investigators, we have, however, found that when frog’s skin is placed in Ringer’s solution a condition of extreme melanophore contraction supervenes, so that this mode of treatment is useless for demonstrating the action of drugs whose application induces expanded melanophores to contract. As Spaeth, who has studied the effect of drugs on the melanophores of fish scales, rightly insists, the administration of drugs to the intact animal is fraught with formidable objections. But the disadvantages are preeminently of the nature of limitations. Of these the most obvious are: first, the difficulty in discriminating between local, peripheral, central, or reflex effects, when the seat of action of the drug is not homogeneous, e . g . in the case of atropine which has peripheral (parasympathetic) as well as central effects, or of veratrine, which acts directly on contractile tissue, and reflexly through its excitatory effect on sensory nerve endings; secondly, the possibility of inducing death, or interfering unduly with the circulation, with quantities subminimal to produce pigmentary response. However, if these limitations are recognised, the study of drug administration can, in the light of existing pharmacological knowledge, be used to explore the possible existence of a nervous mechanism of control in colour change. In this connection both direct experiment and the study of drug administration, have prompted a bewildering series of conflicting statements from a body of investigators so numerous that it is impossible to mention them individually. Fuchs, in his extensive survey of the literature—there are about 150 papers on Amphibian pigmentary changes—comments upon this lack of unanimity: “Wir müssen diese verschiedene Reaktionen auf ein und dasselbe Reagens als physiologische Artverschiedenheiten ansehen.” Foremost among those who have studied pigmentary responses to drugs in Amphibia are Biedermann, Bimmermann, Carnot, and Fuchs (1906). The reagents investigated by previous workers include veratrine, strychnine, santonin, curare, brucine, coniine, morphine, atropine, and eserine; but none have systematically applied modern knowledge of pharmacological reagents, using those whose action is most instructive. Apart from Lieben’s important work (1906) on adrenalin, the only observation which is specially interesting is Fuchs’ discovery that nicotine in amount adequate to produce motor paralysis induces darkening of the frog’s skin.

scholarly journals The lantern shark's light switch: turning shallow water crypsis into midwater camouflage

2010 ◽  
Vol 6 (5) ◽  
pp. 685-687 ◽  
Author(s):  
Julien M. Claes ◽  
Jérôme Mallefet
Keyword(s):  
Shallow Water ◽  
Deep Sea ◽  
Light Emission ◽  
Colour Change ◽  
Hormonal Control ◽  
Nervous Control ◽  
Luminous Bacteria ◽  
Physiological Colour Change ◽  
Physiological Suppression

Bioluminescence is a common feature in the permanent darkness of the deep-sea. In fishes, light is emitted by organs containing either photogenic cells (intrinsic photophores), which are under direct nervous control, or symbiotic luminous bacteria (symbiotic photophores), whose light is controlled by secondary means such as mechanical occlusion or physiological suppression. The intrinsic photophores of the lantern shark Etmopterus spinax were recently shown as an exception to this rule since they appear to be under hormonal control. Here, we show that hormones operate what amounts to a unique light switch, by acting on a chromatophore iris, which regulates light emission by pigment translocation. This result strongly suggests that this shark's luminescence control originates from the mechanism for physiological colour change found in shallow water sharks that also involves hormonally controlled chromatophores: the lantern shark would have turned the initial shallow water crypsis mechanism into a midwater luminous camouflage, more efficient in the deep-sea environment.

Erratum

1971 ◽  
Vol 54 (1) ◽  
pp. 1-1
Author(s):  
GENTLE M. J.
Keyword(s):  
Colour Change ◽  
Nervous Control ◽  
Phoxinus Phoxinus

The central nervous control of colour change in the minnow (Phoxinus phoxinus L.) Discussion, line 4: Delete ‘unlike the fish used by the Dijkgraaf’

scholarly journals THE STRUCTURE AND DIFFERENTIATION OF THE SPECIFIC CELLULAR ELEMENTS OF THE PARS INTERMEDIA OF THE HYPOPHYSIS OF THE DOMESTIC PIG

1922 ◽  
Vol 36 (1) ◽  
pp. 141-156 ◽  
Author(s):  
Siegfried Maurer ◽  
Dean Lewis
Keyword(s):  
Third Ventricle ◽  
Pars Intermedia ◽  
Posterior Lobe ◽  
Domestic Pig ◽  
Pars Nervosa ◽  
Thin Membranes ◽  
Pituitary Secretion ◽  
Mechanical Separation ◽  
First Time ◽  
Fetal Pig

The bearing of these results on the Herring-Cushing theory of pituitary secretion is apparent. For the first time a true secretion antecedent has been demonstrated in the cells of the pars intermedia, an antecedent which appears in the cells at the same period of development at which active pressor effects may be obtained from the gland extracts. The route of export of this material from the gland to its point of utilization, however, is unknown; it may go by way of the blood or, as required by the Herring theory, by the transneural route to the third ventricle. The objections to the latter conclusion have been amply expanded in the introduction to this paper, but here may be emphasized the fact that the fetal pig hypophysis contains no hyaline bodies. Indeed they are rare in the adult, though there may be seen in the cells of the pars nervosa in the processes of its intrinsic cells, granular deposits which we believe to be the antecedents of the hyaline bodies but which in the pig rarely are discharged and aggregated into discrete masses as in other mammals. The fact that some observers have obtained positive pressor effects from the nervous part of the posterior lobe, exclusive of the pars intermedia, need not weigh very heavily in attempting to trace the course of the secretion, when we reflect that the difficulties of making such a mechanical separation are almost insuperable, and that the chemical product of the pars intermedia is so soluble and vanishes from the cells so rapidly that it may well be diffusible through the thin membranes which intervene and penetrate post mortem into adjacent parts. We are inclined, therefore, to the view that the secretion leaves the gland by the vascular route rather than by way of the interfibrillar spaces of the pars nervosa.

scholarly journals The pigmentary effector system VII—The chromatic function in Elasmobranch fishes

1936 ◽  
Vol 120 (817) ◽  
pp. 142-158 ◽  
Keyword(s):  
Pituitary Gland ◽  
Colour Change ◽  
Anterior Lobe ◽  
Physiological Mechanisms ◽  
Rapid Responses ◽  
Effector System ◽  
Aquatic Vertebrates ◽  
Colour Changes ◽  
Elasmobranch Fishes ◽  
Phylogenetic Character

It is now firmly established that the coordination of chromatic response in Amphibia is predominantly, if not exclusively, due to the liberation of hormones by reflexes involving visual and skin receptors, and in Reptiles to direct innervation of the pigmentary effector organs (Hogben and Mirvish, 1928; Zoond and Eyre,1934). Among aquatic vertebrates examples of both types of coordination occur. The bulk of available evidence points to the conclusion that the chromatophores of Teleostean fishes are directly innervated and that the comparatively rapid responses which are exhibited by several species are brought about by simple reflex action. That this is not true of cyclostomes has recently been shown by J. Z. Young (1935) whose experiments demonstrate the archaic phylogenetic character of the control exercised by the Amphibian pituitary gland. From an evolutionary standpoint it would not be surprising to find among physiological mechanisms in Teleostean fishes examples of specialization comparable to the strikingly aberrant features which their anatomical organization displays. On the other hand it would be remarkable if the cartilaginous fishes proved an exception to a rule which applies both to Cyclostomes and to Amphibia. Recent work on the colour changes of Elasmobranchs supports the conclusion that the coordination of colour change in Teleostean fishes is highly specialized. Lundstrom and Bard (1932) have shown that total removal of the pituitary gland in Mustelis canis results in a state of pallor which ensues within a few hours after operation, reaching its limit about the twelfth post-operative hour. In their experiments the animals usually succumbed after three or four days with loss of righting reactions. Only a few survived as long as a week. The effect was not produced by removal of the anterior lobe alone, nor by severe traumatization of the hypothalamus. Complete darkening of the pale operated animals followed injections or extracts of ox pituitary and of the pituitary of the fish itself, the quantity present in the fish gland being greatly in excess of the amount requisite to induce full expansion of the dermal melanophores. The present investigation, undertaken to throw further light on the evolution of the chromatic function in Vertebrates, is based on several species of Elasmobranch fishes, namely the skates, Raia Brachiura, R. clavata, R. maculata, R. microcelatus , the speckled dogfish Scyllium canicula , the banded dogfish or nursehound S. catulus (Scylliorhinusstellaris) , and the monkfish Rhina squatina . The writer is indebted to Mr. G. A. Steven for invaluable assistance in identifying the various species used. In all these species the pigmentary effector system of the integument, like that of the American dogfish Mustelis canis , closely resembles that of Amphibia, and consists of three types of chromatophores which are more or less evenly distributed. These are the epidermal melanophores, larger more richly branched dermal melanophores, and xanthophores containing an orange yellow pigment. The same agencies, in the fishes to be described, evoked or maintained pigment diffusion (“expansion”) of all three types, and the concentration of pigment in the centre of the cell (“contraction”) in all three types. That is to say, the xanthophores of a skate or dogfish which was maximally pale were always fully contracted like the melanophores of both kinds, and the xanthophores of a dark animal were fully expanded. This is true of some—but not all—Amphibia. In general appearance the chromatophores of the species studied are more like those of a Urodele than those of a Teleost.

scholarly journals Croonian lecture - Chromatic behaviour

1942 ◽  
Vol 131 (863) ◽  
pp. 111-136 ◽  
Keyword(s):  
Branching Processes ◽  
Colour Change ◽  
Sensu Stricto ◽  
Muscle Fibres ◽  
Pigment Granules ◽  
Effector System ◽  
Surface Variation ◽  
Colour Changes ◽  
Blood Pigment

Visible colour changes of animals are of two types, those which result from build-up or breakdown of pigments, and those which result from their redistribution. Assumption of winter dress by some mammals and of breeding dress by some fishes are familiar examples of the former. The proverbial behaviour of the chameleon illustrates the latter. Mere redistribution of pigment may itself come about in several ways. It may result from the responses of contractile tissues sensu stricto or from those of pigmentary effector organs sui generis . Visible colour changes due to the response of contractile tissues include: ( a ) the familiar phenomena of blushing, blanching and cyanosis due to surface variation of the quantity of blood pigment, i. e. to vasodilation, vasoconstriction and capillary stasis; ( b ) the more specialized chromatic behaviour of cephalopods. Cephalopod colour change is brought about by relaxation and contraction of radially disposed plain muscle fibres attached to pigment-containing vesicles. What follows refers only to chro­matic behaviour accomplished by effector organs other than muscle fibres. At present we know of two main types: (i) The pigmentary effector system of vertebrates, of Crustacea and of Annelida (Wells 1932) consists of cells in which pigment granules or droplets migrate to the periphery of diffusely branching processes, thereby offering more surface for absorption of radiation.

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