Physiological adaptations of red blood cells during aestivation in the south American lungfish Lepidosiren paradoxa.

The South American lungfish Lepidosiren paradoxa inhabits areas with variable pluvial regimes. During aestivation (dormancy state observed in some species during dry seasons), the prolonged period of dryness imposes osmotic stress. We aimed to investigate the physiological and morphological adaptations of RBCs in Lepidosiren paradoxa during aestivation.

Classification of sex-dependent specific behaviours by tri-axial acceleration in the tegu lizard Salvator merianae.

Validated patterns of behaviour detected by tri-axial acceleration in the laboratory can be used for remote measurements of free-living animals. The tegu lizard naturally occupies diverse biomes in South America and presents ecological threats in regions where it was artificially introduced. We aimed to validate the use of tri-axial acceleration to distinguish among behaviours of male and female tegus in captivity by comparing observed behaviours to recorded acceleration data.

Long-term effects on cardiorespiratory and behavioral responses in male and female rats prenatally exposed to cannabinoid.

Development of the respiratory system can be affected by the use of drugs during pregnancy, as the prenatal phase is highly sensitive to pharmacological interventions, resulting in long-term consequences. The deleterious effects of external cannabinoids during gestation may be related to negative interference in central nervous system formation, cardiorespiratory system function, and behavioral disorders. Nevertheless, the impact of external cannabinoids on cardiorespiratory network development, chemosensitivity, and its future consequences in adulthood is still unclear.

Locus coeruleus noradrenaline depletion and its differential impact on CO-induced panic and hyperventilation in male and female mice.

CO exposure has been used to investigate the panicogenic response in patients with panic disorder. These patients are more sensitive to CO, and more likely to experience the "false suffocation alarm" which triggers panic attacks. Imbalances in locus coeruleus noradrenergic (LC-NA) neurotransmission are responsible for psychiatric disorders, including panic disorder.

Do newborn lambs with black and white hair-coats in an equatorial semi-arid environment maintain homeothermy?

We assessed newborn lambs from two hair-coat sheep breeds, the black Santa Ines (n = 29) and white Dorper (n = 26), to determine how they behaviourally and physiologically respond to the prevailing thermal conditions in an equatorial semi-arid environment. Measurements of hair-coat surface temperature, rectal temperature and the lambs' exposure to sun were recorded across the first 24 h of life every hour, after the lambs had received colostrum. Lambs and ewes were kept in a lambing pen and could freely move between a shaded area or be exposed to sun.

Exercise derived myokine irisin as mediator of cardiorespiratory, metabolic and thermal adjustments during central and peripheral chemoreflex activation.

Exercise elicits physiological adaptations, including hyperpnea. However, the mechanisms underlying exercise-induced hyperpnea remain unresolved. Skeletal muscle acts as a secretory organ, releasing irisin (IR) during exercise.

Mitochondrial function in skeletal muscle contributes to reproductive endothermy in tegu lizards (Salvator merianae).

Aim: In cyclic climate variations, including seasonal changes, many animals regulate their energy demands to overcome critical transitory moments, restricting their high-demand activities to phases of resource abundance, enabling rapid growth and reproduction. Tegu lizards (Salvator merianae) are ectotherms with a robust annual cycle, being active during summer, hibernating during winter, and presenting a remarkable endothermy during reproduction in spring. Here, we evaluated whether changes in mitochondrial respiratory physiology in skeletal muscle could serve as a mechanism for the increased thermogenesis observed during the tegu's reproductive endothermy.

Inhibition of Pro-Inflammatory Microglia with Minocycline Improves Cognitive and Sleep-Wake Dysfunction Under Respiratory Stress in a Sporadic Model for Alzheimer's Disease.

Background: Neuroinflammation in Alzheimer's disease (AD) can occur due to excessive activation of microglia in response to the accumulation of amyloid-β peptide (Aβ). Previously, we demonstrated an increased expression of this peptide in the locus coeruleus (LC) in a sporadic model for AD (streptozotocin, STZ; 2 mg/kg, ICV). We hypothesized that the STZ-AD model exhibits neuroinflammation, and treatment with an inhibitor of microglia (minocycline) can reverse the cognitive, respiratory, sleep, and molecular disorders of this model.

Heat stress affects breathing and metabolism of chicks incubated at high temperature.

Global warming poses serious implications to animal physiology and a gradual increase in ambient temperature affects all living organisms, particularly fast-growing selected species. We recorded ventilation (V̇), body temperature (T), oxygen consumption (V̇O) and respiratory equivalent (V̇/V̇O) of 14-day-old (14d) male and female chicks at room air conditions, hypercapnia and hypoxia at heat stress (HS, 32 °C). These chicks had previously been exposed to control (CI, 37.

Energy cost of physical activities in growing broilers.

1. The time-energy budget method estimates the energy used for physical activity (PA) by integrating behaviour PA patterns with energy cost for specific PAs. Nevertheless, information about individual energy cost by type of PA are not available and so this study estimated the energy cost of PA for growing broilers.

Sex- and age-specific respiratory alterations induced by prenatal exposure to the cannabinoid receptor agonist WIN 55,212-2 in rats.

Background And Purpose: Cannabis legalization has risen in many countries, and its use during pregnancy has increased. The endocannabinoid system is present in the CNS at early stages of embryonic development, and regulates functional brain maturation including areas responsible for respiratory control, data on the influence of external cannabinoids on the development of the respiratory system and possible consequences during postnatal life are limited.

Experimental Approach: We evaluated the effects of prenatal exposure to synthetic cannabinoid (WIN 55,212-2 [WIN], 0.

Intra-uterine diazepam exposure decreases the number of catecholaminergic and serotoninergic neurons of neonate rats.

Benzodiazepines, such as diazepam (DZP), are used to treat anxiety disorders, and are prescribed to pregnant woman for therapeutic purposes. Concerns regarding their consequences on postnatal development rise as they cross the placenta and interact with the embryo. Occurrence of malformation and behavioral syndromes have been reported for different ages, but little is known about their effects on the brain after exposure during intrauterine life.

Metabolic and respiratory chemosensitivity and brain monoaminergic responses to cold exposure in chicks subjected to thermal manipulation during incubation.

We evaluated ventilation (V˙), body temperature (T), oxygen consumption (V˙ O), respiratory equivalent (V˙/ V˙ O), and monoamine concentrations of 14-day-old (14d) male and female chicks from eggs incubated at low (LT, 36 °C), control (CT, 37.5 °C) and high (HT, 39 °C) temperature during the early embryonic phase, to normoxia, hypercapnia and hypoxia under exposure to cold environment (20 °C). At normoxia, acute cold exposure did not affect the ventilatory variables, with the exception of HT males, in which cold prevented the reduced V˙ observed under thermoneutral conditions.

Cutaneous TRPV4 Channels Activate Warmth-Defense Responses in Young and Adult Birds.

Transient receptor potential vanilloid 4 (TRPV4) channels are sensitive to warm ambient temperatures (Ts), triggering heat loss responses in adult rats in a Ts range of ∼26-30°C. In birds, however, the thermoregulatory role of TRPV4 has never been shown. Here, we hypothesized that stimulation of TRPV4 induces thermolytic responses for body temperature (T) maintenance in birds, and that this function is already present in early life, when the T range for TRPV4 activation does not represent a warm condition for these animals.

Sexually dimorphic effects of prenatal diazepam exposure on respiratory control and the monoaminergic system of neonate and young rats.

Pregnancy is highly affected by anxiety disorders, which may be treated with benzodiazepines, especially diazepam (DZP), that can cross the placental barrier and interact with the fetal GABAergic system. We tested whether prenatal exposure to DZP promotes sex-specific postnatal changes in the respiratory control of rats. We evaluated ventilation ([Formula: see text]) and oxygen consumption ([Formula: see text] O) in resting conditions and under hypercapnia (7% CO) and hypoxia (10% O) in newborn [postnatal day (P) 0-1 and P12-13)] and young (P21-22) rats from mothers treated with DZP during pregnancy.

Prenatal fluoxetine has long-lasting, differential effects on respiratory control in male and female rats.

Serotonin (5-HT) is an important modulator of brain networks that control breathing. The selective serotonin reuptake inhibitor fluoxetine (FLX) is the first-line antidepressant drug prescribed during pregnancy. We investigated the effects of prenatal FLX exposure on baseline breathing, ventilatory and metabolic responses to hypercapnia and hypoxia as well as number of brainstem 5-HT and tyrosine hydroxylase (TH) neurons of rats during postnatal development (P0-82).

Metabolic trade-offs favor regulated hypothermia and inhibit fever in immune-challenged chicks.

The febrile response to resist a pathogen is energetically expensive, while regulated hypothermia seems to preserve energy for vital functions. We hypothesized here that immune-challenged birds facing metabolic trade-offs (reduced energy supply/increased energy demand) favor a regulated hypothermic response at the expense of fever. To test this hypothesis, we compared 5 day old broiler chicks exposed to fasting, cold (25°C), and fasting combined with cold with a control group fed under thermoneutral conditions (30°C).

Starch and fiber intake effects on energy metabolism, growth, and carapacial scute pyramiding of red-footed tortoise hatchlings (Chelonoidis carbonaria).

Tortoise husbandry includes reports of excessive growth and carapace pyramiding, although triggers still remain to be fully elucidated. Juvenile red-footed tortoises (Chelonoidis carbonaria) were fed with two different diets, one high in fiber (HF; 14.2% crude fiber; 39.

Thermal Acclimation to the Highest Natural Ambient Temperature Compromises Physiological Performance in Tadpoles of a Stream-Breeding Savanna Tree Frog.

Amphibians may be more vulnerable to climate-driven habitat modification because of their complex life cycle dependence on land and water. Considering the current rate of global warming, it is critical to identify the vulnerability of a species by assessing its potential to acclimate to warming temperatures. In many species, thermal acclimation provides a reversible physiological adjustment in response to temperature changes, conferring resilience in a changing climate.

Seasonal changes in steroid and thyroid hormone content in shed skins of the tegu lizard Salvator merianae.

Sampling blood for endocrine analysis from some species may not be practical or ethical. Quantification of hormones extracted from nontypical sample types, such as keratinized tissues, offers a less invasive alternative to the traditional collection and analysis of blood. Here, we aimed to validate assays by using parallelism and accuracy tests for quantification of testosterone, corticosterone, progesterone, and triiodothyronine (T) in shed skins of tegu lizards.

Embryonic Thermal Manipulation Affects Ventilation, Metabolism, Thermal Control and Central Dopamine in Newly Hatched and Juvenile Chicks.

The first third of incubation is critical for embryonic development, and environmental changes during this phase can affect the physiology and survival of the embryos. We evaluated the effects of low (LT), control (CT), and high (HT) temperatures during the first 5 days of incubation on ventilation ( ), body temperature (Tb), oxygen consumption ( O), respiratory equivalent ( / O), and brain monoamines on 3-days-old (3d) and 14-days-old (14d) male and female chickens. The body mass of LT animals of both ages and sexes was higher compared to HT and CT animals (except for 3d males).

5-HT neurons of the medullary raphe contribute to respiratory control in toads.

Air-breathing vertebrates undergo respiratory adjustments when faced with disturbances in the gas composition of the environment. In mammals, the medullary raphe nuclei are involved in the neuronal pathway that mediates the ventilatory responses to hypoxia and hypercarbia. We investigate whether the serotoninergic neurons of the medullary raphe nuclei of toads (Rhinella diptycha) play a functional role in respiratory control during resting conditions (room air), hypercarbia (5% CO), and hypoxia (5% O).

Influence of incubation temperature on embryo development, hatchling morphology and early growth rate in red-footed tortoise (Chelonoidis carbonaria).

Reptile embryos respond to temperature changes with metabolic and physiological adjustments that influence hatchling success, phenotype, behaviour, and growth rate. Climate change and global warming can affect the reptile population by altering the frequencies of hatchling survival and phenotypes. Therefore, previous studies proposed artificial incubation as a potential strategy for mitigating these effects.