Kenia C Bicego

São Paulo State University | Unesp · Departamento de Morfologia e Fisiologia Animal

Early life is a challenging phase because of the high rates of morphophysiological development and growth. Changes in ambient temperature, which directly affect energy metabolism and digestive functions in ectotherms, may be of great impact during this phase. We addressed this issue in red-footed tortoise (Chelonoidis carbonaria) hatchlings kept in...

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...

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 (V̇E), body temperature (TB), oxygen consumption (V̇O2) and respiratory equivalent (V̇E/V̇O2) of 14-day-old (14d) male and female chicks at roo...

• The time-energy budget method estimates the energy used for physical activity (PA) based on recorded daily patterns and indirect calorimetry. 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. • An indirect calorimetry system for single bir...

Background and purpose: Cannabis legalization has risen in many countries, and its use during pregnancy has increased. The endocannabinoid system is present in the central nervous system (CNS) at the early stages of embryonic development and regulates functional brain maturation, including in areas responsible for respiratory control. Regardless o...

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...

We evaluated ventilation (V˙E), body temperature (TB), oxygen consumption (V˙ O2), respiratory equivalent (V˙E/ V˙ O2), 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...

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 ([...

Transient receptor potential vanilloid 4 (TRPV4) channels are sensitive to warm ambient temperatures (Tas), triggering heat loss responses in adult rats in a Tas 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 temper...

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 on baseline breathing, ventilatory and metabolic responses to hypercapnia and hypoxia as well...

Irisin has been identified as an important exercise-induced myokine that acts in different physiological systems; however, little is known about the participation of irisin in cardiorespiratory and basal metabolic control. Therefore, the present study evaluated the effect of intracerebroventricular (icv) injection of vehicle or irisin (IR, 0.425 µg...

The CO2 exposure has been used to investigate the panicogenic response in patients with panic and other anxiety disorders since these patients are more sensitive to this stimulus, and therefore, more likely to experience the "suffocation false alarm" which, in turn, triggers the panic attack. It is well described that imbalances in the modulation o...

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 under metabolic trade-offs (reduced energy supply / increased energy demand) favor a regulated hypothermic response at the expense of fever. To test this hyp...

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...

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; 39.2% neutral detergent fiber, NDF; dry matter basis, DMB) and one high in starch...

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 pro...

Introduction. Complete diets for raising growing tortoises in captivity commonly present low fiber content and high energy density, mainly in the form of starch. This has been associated with accelerated growth, reduced body mineral content, and carapace pyramiding in several reptile species. The present study evaluated the growth of hatchlings of...

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 ( V . E ), body temperature (Tb), oxygen consumpti...

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 inc...

The pontine A5 noradrenergic group contributes to the maturation of the respiratory system before birth in rats. These neurons are connected to the neural network responsible for respiratory rhythmogenesis. In the present study, we investigated the participation of A5 noradrenergic neurons in neonates (P7–8 and P14–15) in the control of ventilation...

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 nuc...

Multiple factors can influence the immune response of ectothermic vertebrates, including body temperature, gonadal steroids, and seasonality, in ways that are thought to reflect trade-offs between energetic investment in immunity vs. reproduction. Hibernating tegu lizards (Salvator merianae) are a unique model to investigate how immunocompetence mi...

Key points: The costs associated with immune and thermal responses may exceed its benefits to the host during severe inflammation. In this case, regulated hypothermia instead of fever can occur in rodents as a beneficial strategy to conserve energy for vital functions with consequent tissue protection and hypoxia prevention. We tested the hypothes...

The brainstem region medullary raphe modulates non-shivering and shivering thermogenesis and cutaneous vasomotion in rodents. Whether the same scenario occurs in the other endothermic group, i.e. birds, is still unknown. Therefore, we hypothesised that the medullary raphe modulates heat gain and loss thermoeffectors in birds. We investigated the ef...

The neural network that regulates breathing shows a significant sexual dimorphism. Ovarian hormones contribute to this distinction as, in rats, ovariectomy reduces the ventilatory response to CO2. Microglia are neuroimmune cells that are sensitive to neuroendocrine changes in their environment. When reacting to challenging conditions, these cells s...

Animals use behaviour to alleviate the feelings of hot and cold, by avoiding situations that arouse those feelings. That is the basis of behavioural thermoregulation. By employing behavioural thermoregulation, domestic animals can manipulate heat exchanges between body surface and surrounding environment, thus reducing demands for evaporative water...

Light/dark cycle affects the physiology of vertebrates and hypothalamic orexin neurons (ORX) are involved in this function. The breathing pattern of the green iguana changes from continuous to episodic across the light/dark phases. Since the stimulatory actions of ORX on breathing are most important during arousal, we hypothesized that ORX regulate...

Background Chronic inflammation plays an important role in the cascade of molecular events in the brain of patients with Alzheimer's disease (AD). Preclinical studies have shown that minocycline has a potent anti‐inflammatory effect exerted by its neuroprotective action in various neurodegenerative diseases, such as AD. Thus, we tested the hypothes...

In worst-case scenario of the coronavirus disease 2019 (COVID-19), the acute respiratory distress syndrome (ARDS) is the main cause of mortality in patients, which could lead to multiorgan failure by fatal cytokine release (cytokine storm). In most cases, COVID-19 patients present persistent high fever associated with inflammatory responses against...

Many diseases of the respiratory system occur differently in males and females indicating a possible role of gonadal hormones in respiratory control. We hypothesized that testosterone is important for the ventilatory chemosensitivity responses in males. To test this hypothesis, we evaluated ventilation (V E ), metabolic rate and body temperature (T...

Download gratuito do livro disponível no site da FEU no endereço: http://www.culturaacademica.com.br/catalogo/fisiologia-termica-de-vertebrados/

Download gratuito do livro disponível no site da FEU no endereço: http://www.culturaacademica.com.br/catalogo/fisiologia-termica-de-vertebrados/

Dioxin exposure during bird embryonic development disrupts immunity as well as mechanisms involved in energy metabolism, potentially affecting negatively acute phase responses to pathogens. Thus, we hypothesized that embryonic exposure to TCDD (2,3,7,8‐Tetrachlorodibenzodioxin) changes metabolism and blood physiology of domestic chicks, affecting t...

The anteroventral preoptic region (AVPO) of the hypothalamus is involved in both temperature and breathing regulation. This area densely express cannabinoid receptors type 1 (CB1) that modulates both excitatory and inhibitory synaptic transmission. However, it is still unknown if the endocannabinoid system located in the AVPO participates in breath...

The first third of the incubation is determinant for the embryonic development and the temperature is considered one of the most important factors that can affect the quality and the survival rate of the embryos. The aim of this study was to evaluate the effect of changes in the temperature of incubation (36 °C‐cold; 37.5 °C‐thermoneutral and 39 °C...

The use of drugs of abuse during pregnancy can severely affect the development of physiological systems including the central respiratory network, mainly because prenatal period is extremely susceptible to external and pharmacological interventions that may cause postnatal consequences to the offspring. The endocannabinoid system is already present...

It is demonstrated in mammals, at least in rats, that caudal brain regions, such as raphe nuclei, are involved in the modulation of thermoeffectors for heat loss and heat production, such as peripheral vasodilation/vasoconstriction, nonshivering and shivering thermogenesis. If the same scenario occurs in the other group of endothermic vertebrates,...

Gestation is a critical period for the development of the respiratory system and interventions, such as the use of benzodiazepines (BZs) for treatment of psychic disorders, at this stage, may compromise this system. BZs, such as Diazepam (DZ) are one of the most common drugs prescribed to treat anxiety disorders but it can compromise the developmen...

The respiratory system undergoes significant development during the postnatal phase. Maturation of brainstem catecholaminergic (CA) neurons is important for the control and modulation of respiratory rhythmogenesis, as well as for chemoreception in early life. We demonstrated an inhibitory role for CA neurons in CO2 chemosensitivity in neonatal and...

The concentration of CO2 in the environment surrounding the embryo impacts development and may also influence the cardiorespiratory responses after hatching. Therefore, we aimed to evaluate the cardiorespiratory and thermal responses to hypercapnia in chicks that were exposed to CO2 during embryonic development, i.e., incubation. Embryos were incub...

Recently, we have described, in non-genetically modified rats, that peripheral transient receptor potential vanilloid-4 (TRPV4) channels are activated and trigger warmth-defence responses at ambient temperatures of 26–30 °C. Evidence points to the presence of TRPV4 in the medial preoptic area, a region described to be involved in the activation of...

Life history transitions and hormones are known to interact and influence many aspects of animal physiology and behavior. The South-American tegu lizard (Salvator merianae) exhibits a profound seasonal shift in metabolism and body temperature, characterized by high daily activity during warmer months, including reproductive endothermy in spring, an...

Carbon dioxide (CO2) and oxygen (O2) influence the breathing pattern of reptiles, especially when CO2 is in excess or O2 at low concentrations and the effects of these gases on the respiratory response varies according to the species. In addition to respiratory gases, seasonal changes can also modulate breathing pattern and ventilatory responses to...

The embryonic development of parabronchi occurs mainly during the second half of incubation in precocious birds, which makes this phase sensitive to possible morphological modifications induced by O2 supply limitation. Thus, we hypothesized that hypoxia during the embryonic phase of parabronchial development induces morphological changes that remai...

Receptors of the transient receptor potential (TRP) channels superfamily are expressed in many tissues and have different physiological functions. However, there are few studies investigating the role of these channels in cardiorespiratory control in mammals. We assessed the role of central and peripheral TRPV1 receptors in the cardiorespiratory re...

Neurodegenerative diseases such as Alzheimer's may impair breathing function; however, how these breathing deficits occur is not completely understood. Therefore, it is important to evaluate how Alzheimer's disease (AD) can alter breathing activity. In light of this, we used an animal model for sporadic AD induced by intracerebroventricular (icv) i...

American bullfrog tadpoles exhibit an inhibitory vagal tone in the heart, while in adults; vagal tone becomes considerably reduced and virtually independent of temperature. Temperature effects on cardiac autonomic tonus in amphibian's larval stages have never been investigated. Therefore, we evaluated the effect of different temperatures (15, 25, a...

Peripheral TRPV4 is activated and triggers warmth‐defense responses at ambient temperatures (T as ) of 26–30°C in non‐genetically modified rats. TRPV4 also can be found in medial preoptic area (MPA), region known by being involved with activation of heat loss mechanisms. Then, the aim of this study was to verify if central TRPV4 in the MPA plays a...

Respiratory system regulates acid‐base balance by eliminating carbon dioxide (CO 2 ), with PCO 2 /pH variations detected mainly by central chemoreceptors. In mammals, serotonergic neurons (5‐HT) have been demonstrated to play a crucial role in the ventilatory response to CO 2 . It is known that birds have central CO 2 /pH chemoreceptors and that 5‐...

The tegu lizard Salvator merianae is a large, widely distributed teiid lizard endemic to South America that exhibits annual cycles of high activity during the spring and summer, and hibernation during winter. This pattern of activity and hibernation is accompanied by profound seasonal changes in physiology and behavior, including endothermy during...

Besides the typical cognitive decline, patients with Alzheimer's disease (AD) develop disorders of the respiratory system, such as sleep apnea, shortness of breath, and arrhythmias. These symptoms are aggravated with the progression of the disease. However, the cause and nature of these disturbances are not well understood. Here, we treated animals...

Besides the typical cognitive decline, patients with Alzheimer's disease (AD) develop disorders in the respiratory system such as sleep apnea, shortness of breath and arrhythmias. These symptoms are aggravated with progression of the disease. However, the cause and nature of this disturbance are not well understood. Here, we, used an animal model f...

The endocannabinoid system is already present in the central nervous system in the early stages of embryonic development, including in areas responsible for respiratory control. Cannabis sativa (marijuana) is the illicit drug most commonly used during pregnancy. However, the relationship between marijuana use and ventilatory problems in the offspri...

Key points: The brainstem catecholaminergic (CA) modulation on ventilation changes with development. We determined the role of the brainstem CA system in ventilatory control under normocapnic and hypercapnic conditions during different phases of development [postnatal day (P)7-8, P14-15 and P20-21] in male and female Wistar rats. Brainstem CA neur...

Beat-to-beat variation in heart rate (fH) has been used as a tool for elucidating the balance between sympathetic and parasympathetic modulation of the heart. A portion of the temporal changes in fH is evidenced by a respiratory influence (cardiorespiratory interaction) on heart rate variability (HRV) with heartbeats increasing and decreasing withi...

Many adult mammals and birds respond to heat with thermal tachypnea, an increase in breathing frequency with shallow tidal volume, with minimal increase in oxygen consumption (V̇O2 ). This pattern favors heat dissipation by evaporative water loss (EWL) through the respiratory tract. We asked to what extent this response was apparent at the earliest...

Elevated plasmatic concentrations of Testosterone (T) may have an impact over respiratory parameters. Therefore, we evaluated the influence of T on ventilation (V E ) and oxygen consumption (VO 2 ) during room air, hypercapnia (7%CO 2 ) and hypoxia (7%O 2 ) in adult male Wistar rats. V E measurements were obtained using the barometric method (whole...

Sex hormones may influence many physiological processes. Recently, we demonstrated that hormonal fluctuations of cycling female rats do not affect respiratory parameters during hypercapnia. However, it is still unclear whether sex hormones and hormonal fluctuations that occur during the estrous cycle can affect breathing during a hypoxic challenge....

The periaqueductal gray matter (PAG) is rich in mu and kappa opioid receptors, and this system is involved in thermoregulation, analgesia, and defensive behaviors. No study approached the involvement of the PAG opioids in body temperature (Tb) regulation during psychological stress such as restraint. Because activation of mu and kappa receptors inc...

Temperature effects on cardiac autonomic tonus in amphibian larval stages have never been investigated. Therefore, we evaluated the effect of different temperatures (15°C, 25°C, and 30°C) on the cardiorespiratory rates and cardiac autonomic tonus of premetamorphic bullfrog tadpoles, Lithobates catesbeianus To this end, a non-invasive method was dev...

Several evidences indicate that the locus coeruleus (LC) is involved in central chemoreception responding to CO2/pH and displaying a high percentage of chemosensitive neurons (>80%). However, there are no studies about the LC-mediated hypercapnic ventilation performed in females. Therefore, we assessed the role of noradrenergic LC neurons in non-ov...

The A5 area at the ventrolateral pons contains noradrenergic neurons connected with other medullary areas involved in the cardiorespiratory control. Its contribution to the cardiorespiratory regulation was previously evidenced in anesthetized conditions. In the present study, we investigated the involvement of the A5 noradrenergic neurons to the ba...

Environmental changes during perinatal development can affect the postnatal life. In this sense, chicken embryos that experience low levels of O2 over a specific phase of incubation can have their tissue growth reduced and the ventilatory response to hypoxia blunted, at least until hatching. Additionally, exposure to low level of O2 after birth red...

A produção de ATP mitocondrial é a principal fonte de energia para aves, assim como para todos os vertebrados e, para que o ATP seja produzido, a mitocôndria consome oxigênio (O2). O suprimento adequado de O2 é um requisito absoluto, garantindo a sobrevivência dos animais aeróbios. Além disso, é função do sistema respiratório eliminar o dióxido de...

The South American lungfish, Lepidosiren paradoxa inhabits seasonal environments in the Central Amazon and Paraná-Paraguay basins that undergo significant oscillations in temperature throughout the year. They rely on different gas exchange organs, such as gills and skin for aquatic gas exchange while their truly bilateral lungs are responsible for...

Anurans regulate short-term oscillations in blood pressure through changes in heart rate (fH), vascular resistance and lymph hearts frequency. Lung ventilation in anurans is linked to blood volume homeostasis by facilitating lymph return to the cardiovascular system. We hypothesized that the arterial baroreflex modulates pulmonary ventilation in th...