Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Ion uptake in naturally acidic water
AbstractThe first studies on ion regulation in fish exposed to low pH, which were inspired by the Acid Rain environmental crisis, seemed to indicate that ion transport at the gills was completely and irreversibly inhibited at pH 4.0 –4.5 and below. However, work on characid fish native to the Rio Negro, a naturally acidic, blackwater tributary of the Amazon River, found that they possess ion transport mechanisms that are completely insensitive to pHs as low as 3.25. As more species were examined it appeared that pH-insensitiv e transport was a trait shared by many, if not most, species in the Order Characiformes. Subsequ...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - April 23, 2024 Category: Physiology Source Type: research

Methods to estimate body temperature and energy expenditure dynamics in fed and fasted laboratory mice: effects of sleep deprivation and light exposure
AbstractMonitoring body temperature and energy expenditure in freely-moving laboratory mice remains a powerful methodology used widely across a variety of disciplines –including circadian biology, sleep research, metabolic phenotyping, and the study of body temperature regulation. Some of the most pronounced changes in body temperature are observed when small heterothermic species reduce their body temperature during daily torpor. Daily torpor is an energy savi ng strategy characterized by dramatic reductions in body temperature employed by mice and other species when challenged to meet energetic demands. Typical measure...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - April 23, 2024 Category: Physiology Source Type: research

Gulf toadfish (Opsanus beta) gill neuroepithelial cells in response to hypoxia exposure
AbstractNeuroepithelial cells (NECs) within the fish gill contain the monoamine neurochemical serotonin (5-HT), sense changes in the partial pressure of oxygen (PO2) in the surrounding water and blood, and initiate the cardiovascular and ventilatory responses to hypoxia. The distribution of neuroepithelial cells (NECs) within the gill is known for some fish species but not for the Gulf toadfish,Opsanus beta, a fish that has always been considered hypoxia tolerant. Furthermore, whether NEC size, number, or distribution changes after chronic exposure to hypoxia, has never been tested. We hypothesize that toadfish NECs will r...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - April 16, 2024 Category: Physiology Source Type: research

Physiological and behavioural adaptations by big brown bats hibernating in dry rock crevices
AbstractWinter energy stores are finite and factors influencing patterns of activity are important for overwintering energetics and survival. Hibernation patterns (e.g., torpor bout duration and arousal frequency) often depend on microclimate, with more stable hibernacula associated with greater energy savings than less stable hibernacula. We monitored hibernation patterns of individual big brown bats (Eptesicus fuscus; Palisot de Beauvois, 1796) overwintering in rock-crevices that are smaller, drier, and less thermally stable than most known cave hibernacula. While such conditions would be predicted to increase arousal fr...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - April 8, 2024 Category: Physiology Source Type: research

Structure and function of the larval teleost fish gill
AbstractThe fish gill is a multifunctional organ that is important in multiple physiological processes such as gas transfer, ionoregulation, and chemoreception. This characteristic organ of fishes has received much attention, yet an often-overlooked point is that larval fishes in most cases do not have a fully developed gill, and thus larval gills do not function identically as adult gills. In addition, large changes associated with gas exchange and ionoregulation happen in gills during the larval phase, leading to the oxygen and ionoregulatory hypotheses examining the environmental constraint that resulted in the evolutio...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - April 7, 2024 Category: Physiology Source Type: research

Evolution of innate immunity: lessons from mammalian models shaping our current view of insect immunity
AbstractThe innate immune system, a cornerstone for organismal resilience against environmental and microbial insults, is highly conserved across the evolutionary spectrum, underpinning its pivotal role in maintaining homeostasis and ensuring survival. This review explores the evolutionary parallels between mammalian and insect innate immune systems, illuminating how investigations into these disparate immune landscapes have been reciprocally enlightening. We further delve into how advancements in mammalian immunology have enriched our understanding of insect immune responses, highlighting the intertwined evolutionary narr...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - April 4, 2024 Category: Physiology Source Type: research

Cell proliferation and regeneration in the gill
AbstractSeminal studies from the early 20th century defined the structural changes associated with development and regeneration of the gills in goldfish at the gross morphological and cellular levels using standard techniques of light and electron microscopy. More recently, investigations using cell lineage tracing, molecular biology, immunohistochemistry and single-cell RNA-sequencing have pushed the field forward and have begun to reveal the cellular and molecular processes that orchestrate cell proliferation and regeneration in the gills. The gill is a multifunctional organ that mediates an array of important physiologi...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - March 30, 2024 Category: Physiology Source Type: research

Evidence for transporter-mediated uptake of environmental l-glutamate in a freshwater sponge, Ephydatia muelleri
AbstractThe freshwater sponge,Ephydatia muelleri, lacks a nervous or endocrine system and yet it exhibits a coordinated whole-body action known as a “sneeze” that can be triggered by exposure tol-glutamate. It is not known howl-glutamate is obtained byE. muelleri in sufficient quantities (i.e., 70  µM) to mediate this response endogenously. The present study tested the hypothesis thatl-glutamate can be directly acquired from the environment across the body surface ofE. muelleri. We demonstrate carrier mediated uptake of two distinct saturable systems with maximal transport rates (Jmax) of 64.27  ± 4.98 and 25.12...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - March 29, 2024 Category: Physiology Source Type: research

The origins of gas exchange and ion regulation in fish gills: evidence from structure and function
AbstractGill function in gas exchange and ion regulation has played key roles in the evolution of fishes. In this review, we summarize data from the fields of palaeontology, developmental biology and comparative physiology for when and how the gills first acquired these functions. Data from across disciplines strongly supports a stem vertebrate origin for gas exchange structures and function at the gills with the emergence of larger, more active fishes. However, the recent discovery of putative ionocytes in extant cephalochordates and hemichordates suggests that ion regulation at gills might have originated much earlier th...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - March 26, 2024 Category: Physiology Source Type: research

Plasticity changes in iron homeostasis in hibernating Daurian ground squirrels (Spermophilus dauricus) may counteract chronically inactive skeletal muscle atrophy
AbstractDisuse-induced muscular atrophy is frequently accompanied by iron overload. Hibernating animals are a natural animal model for resistance to disuse muscle atrophy. In this paper, we explored changes in skeletal muscle iron content of Daurian ground squirrels (Spermophilus dauricus) during different periods of hibernation as well as the regulatory mechanisms involved. The results revealed that compared with the summer active group (SA), iron content in the soleus muscle (SOL) decreased ( − 65%) in the torpor group (TOR), but returned to normal levels in the inter-bout arousal (IBA); splenic iron content increase...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - March 24, 2024 Category: Physiology Source Type: research

Embryonic methionine triggers post-natal developmental programming in Japanese quail
AbstractEmbryonic development is one of the most sensitive and critical stages when maternal effects may influence the offspring ’s phenotype. In birds and other oviparous species, embryonic development is confined to the eggs, therefore females must deposit resources into the eggs to prepare the offspring for the prevailing post-natal conditions. However, the mechanisms of such phenotypic adjustments remain poorly understo od. We simulated a maternal nutritional transfer by injecting 1 mg ofl-methionine solution into Japanese quail eggs before the onset of incubation. The increase in early methionine concentration in e...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - March 23, 2024 Category: Physiology Source Type: research

Management of inorganic elements by overwintering physiology of cold hardy larvae of European corn borer (Ostrinia nubilalis, Hbn.)
AbstractThe European corn borer (Ostrinia nubilalis, Hbn.), enters diapause, a strategy characterized by arrest of development and reproduction, reduction of metabolic rate and the emergence of increased resistance to challenging seasonal conditions as low sub-zero winter temperatures. The aim of this study was to investigate the potential role of inorganic elements in the ecophysiology ofO. nubilalis, analysing their content in the whole body, hemolymph and fat body, both metabolically active, non-diapausing and overwintering diapausing larvae by ICP-OES spectrometer following the US EPA method 200.7:2001.O nubilalis as m...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - March 13, 2024 Category: Physiology Source Type: research

Telomere dynamics during hibernation in a tropical primate
AbstractHibernation is a widespread metabolic strategy among mammals for surviving periods of food scarcity. During hibernation, animals naturally alternate between metabolically depressed torpor bouts and energetically expensive arousals without ill effects. As a result, hibernators are promising models for investigating mechanisms that buffer against cellular stress, including telomere protection and restoration. In non-hibernators, telomeres, the protective structural ends of chromosomes, shorten with age and metabolic stress. In temperate hibernators, however, telomere shortening and elongation can occur in response to...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - March 11, 2024 Category: Physiology Source Type: research