scholarly journals Role of the Preoptic Area in Sleep and Thermoregulation

2021 ◽  
Vol 15 ◽  
Author(s):  
Rebecca Rothhaas ◽  
Shinjae Chung

Sleep and body temperature are tightly interconnected in mammals: warming up our body helps to fall asleep and the body temperature in turn drops while falling asleep. The preoptic area of the hypothalamus (POA) serves as an essential brain region to coordinate sleep and body temperature. Understanding how these two behaviors are controlled within the POA requires the molecular identification of the involved circuits and mapping their local and brain-wide connectivity. Here, we review our current understanding of how sleep and body temperature are regulated with a focus on recently discovered sleep- and thermo-regulatory POA neurons. We further discuss unresolved key questions including the anatomical and functional overlap of sleep- and thermo-regulatory neurons, their pathways and the role of various signaling molecules. We suggest that analysis of genetically defined circuits will provide novel insights into the mechanisms underlying the coordinated regulation of sleep and body temperature in health and disease.

Water exchange between insects and their environment via the vapour phase includes influx and efflux components. The pressure cycle theory postulates that insects (and some other arthropods) can regulate the relative rates of influx and efflux of water vapour by modulating hydrostatic pressures at a vapour-liquid interface by compressing or expanding a sealed, gas-filled cavity. Some such cavities, like the tracheal system, could be compressed by elevated pressure in all or part of the haemocoele. Others, perhaps including the muscular rectum of flea prepupae, could be compressed by intrinsic muscles. Maddrell Insect Physiol . 8, 199 (1971)) suggested a pressure cycle mechanism of this kind to account for rectal uptake of water vapour in Thermobia but did not find it compatible with quantitative information then available. Newer evidence conforms better with the proposed mechanism. Cyclical pressure changes are of widespread occurrence in insects and have sometimes been shown to depend on water status. Evidence is reviewed for the role of the tracheal system as an avenue for net exchange of water between the insect and its environment. Because water and respiratory gases share common pathways, most published findings fail to distinguish between the conventional view that the tracheal system has evolved as a site for distribution and exchange of respiratory gases and that any water exchange occurring in it is generally incidental and nonadaptive, and the theory proposed here. The pressure cycle theory offers a supplementary explanation not incompatible with evidence so far available. The relative importance of water economy and respiratory exchange in the functioning of compressible cavities such as the tracheal system remains to be explored. Some further implications of the pressure cycle theory are discussed. Consideration is given to the possible involvement of vapour-phase transport in the internal redistribution of water within the body. It is suggested that some insect wings may constitute internal vapour-liquid exchange sites, where water can move from the body fluids to the intratracheal gas. Ambient and body temperature must influence rates of vapour-liquid mass transfer. If elevated body temperature promotes evaporative discharge of the metabolic water burden that has been shown to accumulate during flight in some large insects, their minimum threshold thoracic temperature for sustained flight may relate to the maintenance of water balance. The role of water economy in the early evolution of insect wings is considered. Pressure cycles might help to maintain water balance in surface-breathing insects living in fresh and saline waters, but the turbulence of the surface of the open sea might prevent truly marine forms from using this mechanism.


Author(s):  
Н.М. Геворкян ◽  
Н.В. Тишевская

Цель обзора - анализ клеточной основы патогенеза различных заболеваний в свете регуляторной роли Т-лимфоцитов. Рассматривается роль поликлонального многообразия популяции Т-лимфоцитов, особых свойств этих клеток-представителей гомеостатической системы организма в физиологических процессах в норме и при патологии. Указаны перспективы терапевтического и профилактического воздействий, связанные с использованием суммарных РНК нормальных лимфоидных клеток аллогенной и ксеногенной природы. Указана также возможность создания с помощью лимфоцитарных суммарных РНК адекватных моделей заболеваний человека на пути к развитию персонифицированной медицины. This review provides an analysis of the cellular basis of the pathogenesis of various diseases in the light of the regulatory role of T-lymphocytes. The role of the polyclonal diversity of the population of T-lymphocytes, the special properties of these cells-representatives of the homeostatic system of the body, in physiological processes in health and disease is considered. Prospects for therapeutic and prophylactic effects associated with the use of total RNA of normal lymphoid cells of allogeneic and xenogenic origin are indicated. The possibility of creating, using lymphocytic total RNA, adequate models of human diseases for the development of personalized medicine is also indicated.


2012 ◽  
Vol 33 (2) ◽  
pp. 183-190 ◽  
Author(s):  
Mirko Muzzi ◽  
Francesco Blasi ◽  
Alessio Masi ◽  
Elisabetta Coppi ◽  
Chiara Traini ◽  
...  

Therapeutic hypothermia is of relevance to treatment of increased body temperature and brain injury, but drugs inducing selective, rapid, and safe cooling in humans are not available. Here, we show that injections of adenosine 5′-monophosphate (AMP), an endogenous nucleotide, promptly triggers hypothermia in mice by directly activating adenosine A1 receptors (A1R) within the preoptic area (POA) of the hypothalamus. Inhibition of constitutive degradation of brain extracellular AMP by targeting ecto 5′-nucleotidase, also suffices to prompt hypothermia in rodents. Accordingly, sensitivity of mice and rats to the hypothermic effect of AMP is inversely related to their hypothalamic 5′-nucleotidase activity. Single-cell electrophysiological recording indicates that AMP reduces spontaneous firing activity of temperature-insensitive neurons of the mouse POA, thereby retuning the hypothalamic thermoregulatory set point towards lower temperatures. Adenosine 5′-monophosphate also suppresses prostaglandin E2-induced fever in mice, having no effects on peripheral hyperthermia triggered by dioxymetamphetamine (ecstasy) overdose. Together, data disclose the role of AMP, 5′-nucleotidase, and A1R in hypothalamic thermoregulation, as well and their therapeutic relevance to treatment of febrile illness.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yashar Houshyar ◽  
Luca Massimino ◽  
Luigi Antonio Lamparelli ◽  
Silvio Danese ◽  
Federica Ungaro

Inflammatory Bowel Disease (IBD) is a multifaceted class of relapsing-remitting chronic inflammatory conditions where microbiota dysbiosis plays a key role during its onset and progression. The human microbiota is a rich community of bacteria, viruses, fungi, protists, and archaea, and is an integral part of the body influencing its overall homeostasis. Emerging evidence highlights dysbiosis of the archaeome and mycobiome to influence the overall intestinal microbiota composition in health and disease, including IBD, although they remain some of the least understood components of the gut microbiota. Nonetheless, their ability to directly impact the other commensals, or the host, reasonably makes them important contributors to either the maintenance of the mucosal tissue physiology or to chronic intestinal inflammation development. Therefore, the full understanding of the archaeome and mycobiome dysbiosis during IBD pathogenesis may pave the way to the discovery of novel mechanisms, finally providing innovative therapeutic targets that can soon implement the currently available treatments for IBD patients.


1998 ◽  
Vol 274 (3) ◽  
pp. R783-R789 ◽  
Author(s):  
Thomas E. Scammell ◽  
John D. Griffin ◽  
Joel K. Elmquist ◽  
Clifford B. Saper

Considerable evidence supports the role of prostaglandins in fever production, but the neuroanatomic sites of prostaglandin synthesis that produce fever remain unknown. With the use of a novel microinjection technique, we injected the cyclooxygenase inhibitor ketorolac into the preoptic area (POA) to determine which preoptic regions produce the prostaglandins required for fever. Initial experiments demonstrated that intravenous ketorolac blocked the fever normally produced by lipopolysaccharide (LPS) 5 μg/kg iv. Microinjection of ketorolac into the POA had no effect on body temperature, and injection of artificial cerebrospinal fluid into the POA did not alter LPS fever. Injection of ketorolac into the anteroventral POA markedly decreased the fever produced by LPS, compared with injections into more rostral, caudal, or dorsal locations. These observations indicate that prostaglandin synthesis in the anteroventral preoptic region is necessary for the production of fever.


Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 747 ◽  
Author(s):  
Lola Corzo ◽  
Lucía Fernández-Novoa ◽  
Iván Carrera ◽  
Olaia Martínez ◽  
Susana Rodríguez ◽  
...  

The investigation of new alternatives for disease prevention through the application of findings from dietary and food biotechnology is an ongoing challenge for the scientific community. New nutritional trends and the need to meet social and health demands have inspired the concept of functional foods and nutraceuticals which, in addition to their overall nutritional value, present certain properties for the maintenance of health. However, these effects are not universal. Nutrigenetics describes how the genetic profile has an impact on the response of the body to bioactive food components by influencing their absorption, metabolism, and site of action. The EbioSea Program, for biomarine prospection, and the Blue Butterfly Program, for the screening of vegetable-derived bioproducts, have identified a new series of nutraceuticals, devoid of side effects at conventional doses, with genotype-dependent preventive and therapeutic activity. Nutrigenomics and nutrigenetics provide the opportunity to explore the inter-individual differences in the metabolism of and response to nutrients, achieving optimal results. This fact leads to the concept of personalized nutrition as opposed to public health nutrition. Consequently, the development and prescription of nutraceuticals according to the individual genetic profile is essential to improve their effectiveness in the prevention and natural treatment of prevalent diseases.


2019 ◽  
Vol 20 (10) ◽  
pp. 2519 ◽  
Author(s):  
Sheetal Parida ◽  
Sumit Siddharth ◽  
Dipali Sharma

Adiponectin is one of the most important adipocytokines secreted by adipocytes and is called a “guardian angel adipocytokine” owing to its unique biological functions. Adiponectin inversely correlates with body fat mass and visceral adiposity. Identified independently by four different research groups, adiponectin has multiple names; Acrp30, apM1, GBP28, and AdipoQ. Adiponectin mediates its biological functions via three known receptors, AdipoR1, AdipoR2, and T-cadherin, which are distributed throughout the body. Biological functions of adiponectin are multifold ranging from anti-diabetic, anti-atherogenic, anti-inflammatory to anti-cancer. Lower adiponectin levels have been associated with metabolic syndrome, type 2 diabetes, insulin resistance, cardiovascular diseases, and hypertension. A plethora of experimental evidence supports the role of obesity and increased adiposity in multiple cancers including breast, liver, pancreatic, prostrate, ovarian, and colorectal cancers. Obesity mediates its effect on cancer progression via dysregulation of adipocytokines including increased production of oncogenic adipokine leptin along with decreased production of adiponectin. Multiple studies have shown the protective role of adiponectin in obesity-associated diseases and cancer. Adiponectin modulates multiple signaling pathways to exert its physiological and protective functions. Many studies over the years have shown the beneficial effect of adiponectin in cancer regression and put forth various innovative ways to increase adiponectin levels.


2021 ◽  
Vol 5 (9) ◽  
pp. 586-591
Author(s):  
L.V. Nedosugova ◽  

This paper highlights fundamental views on the mechanisms of maintaining glucose homeostasis as these mechanisms are explained in the lectures on diabetes. The authors discuss hormonal mechanisms of glycemic regulation after meal and fasting, biochemical processes of lipid, protein, and carbohydrate metabolism, and their relationships to maintain energy balance under normal conditions. The role of insulin as the important anabolic hormone stimulating ATP synthesis in a cell and endogenous energy accumulation in liver and muscle glycogen, and neutral lipids, the primary energy substrate, is described. In addition, insulin affects DNA and RNA synthesis via the pentose phosphate pathway and 6-ribulose 5-phosphate, allowing for endogenous protein synthesis in protein malnutrition. The effects of contrainsular hormones supplying the body with energy under starvation (i.e., glucagon and catecholamines, which stimulate glycogenolysis, and glucocorticoids that stimulate gluconeogenesis, thereby maintaining normal blood glucose levels) are described in detail. Furthermore, the paper uncovers the mechanism of switching from carbohydrate metabolism to lipid metabolism mediated by somatotropin to preserve energy balance. Finally, the mechanisms of hyperglycemia in insulin deficiency and the appearance of clinical signs of diabetes and other endocrine disorders are addressed. KEYWORDS: carbohydrate metabolism, glucose, glucose transporters, glycolysis, glycogenolysis, gluconeogenesis, lipolysis. FOR CITATION: Nedosugova L.V. Role of the endocrine system in maintaining glucose homeostasis in health and disease. Russian Medical Inquiry. 2021;5(9):586–591 (in Russ.). DOI: 10.32364/2587-6821-2021-5-9-586-591.


1975 ◽  
Vol 23 (4) ◽  
pp. 453 ◽  
Author(s):  
JW Hudson ◽  
TJ Dawson

Among the marsupials the thermoregulatory response of sweating is uncommon and has only been described in the larger macropodids. Sweating in kangaroos is very unusual in that it only occurs in response to an exercise heat load. The thermoregulatory responses of a smaller, more generalized rat-kangaroo Potorous tridactylus were therefore examined to obtain a more general appreciation of sweating in macropodids. The pattern of heat balance at low and neutral temperatures was characteristic of that previously found for macropodids; body temperature was 35.9 � 0.52 (mean � se). Standard metabolism was only slightly higher than the predicted level for marsupials and minimal conductance was low, c. 1.3 W m-2 per degree Celsius. At moderate air temperatures heat was primarily lost by vasodilation and panting. The thermoregulatory responses at high air temperatures (near or above body temperature) also included copious sweating from the tail, but not from the body generally. Sweating rates of 600-650 g water per m2 per hour were obtained; these are about twice the generally reported rates for eutherians such as cows and horses.


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