Nervous Control of Chromatophores in Teleost Fishes

1964 ◽  
Vol 41 (3) ◽  
pp. 543-552
Author(s):  
J. D. PYE

1. Observations of earlier workers on the chromatic responses to local heating or cooling of the skin of Phoxinus have been confirmed. They have also been found to hold true for anaesthetized fish, in which finer control and observation are possible. 2. The results of a series of nerve-section experiments are held to exclude any possibility that the responses of the intact fish are mediated by a nervous reflex from thermoreceptors in the skin. 3. The responses of melanophores following section of the chromatic motor tracts, or when isolated from the body, are considered to be independent cellular responses. 4. Normal responses in the intact fish show clear temperature thresholds and are completely dependent upon continuation of the respiratory rhythm. 5. Possible physiological mechanisms for mediating these non-adaptive responses are discussed and a new hypothesis is put forward.

Author(s):  
M.P. Sutunkova ◽  
B.A. Katsnelson ◽  
L.I. Privalova ◽  
S.N. Solovjeva ◽  
V.B. Gurvich ◽  
...  

We conducted a comparative assessment of the nickel oxide nanoparticles toxicity (NiO) of two sizes (11 and 25 nm) according to a number of indicators of the body state after repeated intraperitoneal injections of these particles suspensions. At equal mass doses, NiO nanoparticles have been found to cause various manifestations of systemic subchronic toxicity with a particularly pronounced effect on liver, kidney function, the body’s antioxidant system, lipid metabolism, white and red blood, redox metabolism, spleen damage, and some disorders of nervous activity allegedly related to the possibility of nickel penetration into the brain from the blood. The relationship between the diameter and toxicity of particles is ambiguous, which may be due to differences in toxicokinetics, which is controlled by both physiological mechanisms and direct penetration of nanoparticles through biological barriers and, finally, unequal solubility.


Author(s):  
I. V. Cheretaev ◽  
D. R. Khusainov ◽  
E. N. Chuyan ◽  
M. Yu. Ravaeva ◽  
A. N. Gusev ◽  
...  

The purpose of the review is to summarize current literature data and the results of our own research on the analgesic and anti-inflammatory effects of acetylsalicylic acid, as well as the physiological mechanisms underlying them. This acid is the most studied reference representative of salicylates, which is convenient to consider the physiological effects characteristic in general for this group of chemical and medicinal products. Acetylsalicylic acid has analgesic properties against thermal pain and pain caused by electrical stimuli, as well as a pronounced anti-inflammatory effect. The realization of these properties depends on the peculiarities of aspirin metabolism in the body, ion and synaptic mechanisms for controlling the functional state of the cell, neurotransmitter systems of the сentral nervous system, and mechanisms of peripheral and сentral analgesia. Analgesic properties of acetylsalicylic acid founded not only in normal, but also in ultra-small doses. Various physical and especially chemical factors significantly change their effects. This increases the interest in studying the analgesic activity of salicylates and their physiological mechanisms, since such studies can serve as a basis for creating new non-steroidal anti-inflammatory drugs with low toxicity and high safety for patients, and improve the strategy of their practical use. Currently, the most detailed study of the physiological mechanism of analgesic and anti-inflammatory action of aspirin and its main metabolite – salicylic acid. However, it should be note that despite the abundance of existing data obtained in scientific studies of the effects of aspirin and its practical use, there are a number of unexplained aspects of the action of this drug, the mechanism of which has not yet been deciphered. The continuing interest in the effects and mechanisms of action of this drug and in connection with the expansion of its use evidenced by a consistently high number of scientific publications on aspirin in the most famous foreign and domestic publications. At the same time, the number of publications about aspirin is an order of magnitude higher than about any other drug known to humanity.


1998 ◽  
Vol 26 (03n04) ◽  
pp. 265-274 ◽  
Author(s):  
Ching-Liang Hsieh ◽  
Tsai-Chung Li ◽  
Chien-Yu Lin ◽  
Nou-Ying Tang ◽  
Qwang-Yuen Chang ◽  
...  

Although acupuncture has traditionally used the acupoints formula to treat diseases, the physiological mechanisms involved and the effectiveness of therapy remain unclear. This study investigated the physiological mechanism(s) and response to acupuncture stimulation using the acupoints formula. Scalp-recorded potentials P300 were evoked by auditory stimulation of non-target and target in 13 normal adult volunteers. Latencies and amplitudes were measured. Three assessments were performed in each subject over a period of at least one week. Each assessment was divided into a control period with no acupuncture stimulation, followed by an acupuncture period and then a post-acupuncture period. Acupuncture needles were inserted into the body as follows: 1) non-acupoint: acupuncture needles were inserted 2 cm lateral to both Zusanli acupoints; 2) acupoint: acupuncture needles were inserted into both Zusanli acupoints; 3) acupoints formula: acupuncture needles were inserted into both Zusanli and Shousanli acupoints. Our results showed that both acupoint and acupoints formula assessments resulted in a significant decrease of P300 amplitudes during the acupuncture and post-acupuncture periods. However, there was significant difference in P300 amplitudes in the non-acupoint assessment during these periods. P300 changes in latencies and amplitudes were not significantly different between the acupoint assessment and the acupoints formula assessment. We concluded that acupuncture stimulation of both Zusanli acupoints resulted in a decrease of P300 amplitudes, suggesting the involvement of the cerebral cortex in sensory interaction when simultaneous sensations of the two types are received. No similar changes were observed in the non-acupoint assessment, which have been suggested to be related to so-called acupoint specificity. Results obtained using the acupoints formula were not significantly different from those using acupoints alone. These findings suggested that neuropsychological effects from stimulation of Zusanli acupoints and Shousanli acupoints are different.


2001 ◽  
Vol 79 (10) ◽  
pp. 1885-1890 ◽  
Author(s):  
Robert MR Barclay ◽  
Cori L Lausen ◽  
Lydia Hollis

With the development of small implantable data loggers and externally attached temperature-sensitive radio transmitters, increasing attention is being paid to determining the thermoregulatory strategies of free-ranging birds and mammals. One of the constraints of such studies is that without a direct measure of metabolic rate, it is difficult to determine the significance of lowered body temperatures. We surveyed the literature and found that many different definitions have been used to discriminate torpor from normothermy. Many studies use arbitrary temperature thresholds without regard for the normothermic body temperature of the individuals or species involved. This variation makes comparison among studies difficult and means that ecologically and energetically significant small reductions in body temperature may be overlooked. We suggest that normothermic body temperature for each individual animal should be determined and that torpor be defined as occurring when the body temperature drops below that level. When individuals' active temperatures are not available, a species-specific value should be used. Of greater value, however, are the depth and duration of torpor bouts. We suggest several advantages of this definition over those used in the past.


1964 ◽  
Vol 41 (3) ◽  
pp. 553-558
Author(s):  
J. D. PYE

1. The rate of chromatic adaptation to background colour has been examined briefly in thirty-three species of teleost fishes (from nineteen families, eight orders) to test the presence of nervous control of chromatophores. 2. The same fishes have then been tested for chromatic responses to local heating or cooling of the skin. 3. Thermal responses resembling those of Phoxinus have been found in fourteen species which show quick adaptation, but not in thirteen other such species. No thermal responses have been found in any of the six species which do not show quick adaptation. 4. There appears to be no significance in the taxonomic distribution of these results and no new responses to temperature have been found.


2019 ◽  
Vol 96 (8) ◽  
pp. 766-769 ◽  
Author(s):  
Inessa V. Averyanova ◽  
S. I. Vdovenko ◽  
A. L. Maksimov

Natural and climatic conditions of the environment of Northeast Russia and particularly Magadan region are the very factor mostly influencing adaptive responses by individuals inhabiting the region. Compensatory and adaptive responses in indigenes and newcomers of the region can be assumed to have their specific features. In 2009 there was executed the examination of the cardiovascular and respiratory systems and gas exchange in 392 cases aged of 17-19 years, including Europeans (Caucasians) born in the North in the 1st-2nd generation and indigenes. The methodologically similar study was carried out in 2014 in 265 persons, referred to the same cohorts of North-born Caucasians and Indigenes from the Magadan region. The results of the study executed in 2009 testified to a small number of physiological parameters that were reliably different in Caucasians vs. Indigene subjects. In 2014 no difference was found between the two examined cohorts throughout the observed parameters. The revealed changes in gas exchange, external respiration and cardiovascular systems demonstrated by modern young Indigenes of Northeast Russia testified to the fall in the effectiveness of their breathing. All that makes them farther from the classic “polar metabolic type” and their morphofunctional status becomes closer to European male subjects of Northeast Russia. Thus, we can observe a clear tendency towards “convergence in programs” of the adaptive changes between populations of the North residents undergoing similar natural, environmental and social factors.


2001 ◽  
Vol 204 (13) ◽  
pp. 2331-2338 ◽  
Author(s):  
Allen G. Gibbs ◽  
Luciano M. Matzkin

SUMMARYFruit flies of the genus Drosophila have independently invaded deserts around the world on numerous occasions. To understand the physiological mechanisms allowing these small organisms to survive and thrive in arid environments, we performed a phylogenetic analysis of water balance in Drosophila species from different habitats. Desert (cactophilic) species were more resistant to desiccation than mesic ones. This resistance could be accomplished in three ways: by increasing the amount of water in the body, by reducing rates of water loss or by tolerating the loss of a greater percentage of body water (dehydration tolerance). Cactophilic Drosophila lost water less rapidly and appeared to be more tolerant of low water content, although males actually contained less water than their mesic congeners. However, when the phylogenetic relationships between the species were taken into account, greater dehydration tolerance was not correlated with increased desiccation resistance. Therefore, only one of the three expected adaptive mechanisms, lower rates of water loss, has actually evolved in desert Drosophila, and the other apparently adaptive difference between arid and mesic species (increased dehydration tolerance) instead reflects phylogenetic history.


1937 ◽  
Vol 33 (2) ◽  
pp. 191-197
Author(s):  
Y. M. Britvan ◽  
A. A. Graff

Of the various changes in the body that occur during acute bleeding, changes in the rhythm of respiration are less studied. Meanwhile, the issue of periodic respiratory rhythm disorders in acute bleeding is of interest for the clinic in prognostic terms.


2020 ◽  
pp. 96-122
Author(s):  
David Musnick ◽  
Shae Datta

Millions of Americans suffer from traumatic brain injuries and concussion each year. It used to be thought that recovery from a noncomplicated concussion was quick and easy. However, recent research has shown that multiple physiological mechanisms may result from a single impact to the head, and worsen with subsequent injuries. Head injuries have been shown to affect different systems of the body, including the endocrine system, the immune system, and maintenance of the gastrointestinal microbiome. This chapter will review these mechanisms, the sequelae of head injury, and the importance of conducting a thorough evaluation. Integrative methods of treatment and management will be discussed.


1995 ◽  
Vol 269 (2) ◽  
pp. R325-R330 ◽  
Author(s):  
T. K. Bergersen ◽  
M. Eriksen ◽  
L. Walloe

The effect of local heating on blood velocities in arteries supplying the skin of hand and fingers was studied in subjects kept in their thermoneutral zone. The temperature of one hand was steadily raised from 35 to 43 degrees C in 15 min, whereas the control hand was kept in the air or immersed in a water bath at 35 degrees C. Simultaneous blood velocity recordings from the two hands were made continuously using ultrasound Doppler. In the heated hand, a general rise in blood velocity level was seen. However, the spontaneous fluctuations in blood velocity assumed to be caused by synchronous vasomotor activity of the arteriovenous anastomoses (AVAs) remained unchanged and closely correlated with those in the control hand throughout the experiment. Thus the central nervous control of AVA vasomotion seems to be unaffected by local heating. The elevation of blood velocity in the heated hand is probably due to dilatation of other parts of the vascular bed, e.g., ordinary arterioles in the skin. Earlier investigators, using venous occlusion plethysmography, have reported vasoconstriction in the locally heated human finger. No sign of such heat-induced vasoconstriction was found in this study.


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