Search results for "HYPOTHALAMUS"

Surge of Peripheral Arginine Vasopressin in a Rat Model of Birth Asphyxia

2018

Mammalian birth is accompanied by a period of obligatory asphyxia, which consists of hypoxia (drop in blood O2 levels) and hypercapnia (elevation of blood CO2 levels). Prolonged, complicated birth can extend the asphyxic period, leading to a pathophysiological situation, and in humans, to the diagnosis of clinical birth asphyxia, the main cause of hypoxic-ischemic encephalopathy (HIE). The neuroendocrine component of birth asphyxia, in particular the increase in circulating levels of arginine vasopressin (AVP), has been extensively studied in humans. Here we show for the first time that normal rat birth is also accompanied by an AVP surge, and that the fetal AVP surge is further enhanced in…

Brain Control of Plasma Cholesterol Involves Polysialic Acid Molecules in the Hypothalamus

2017

IF 3.566; International audience; The polysialic acid (PSA) is a large glycan that is added to cell-surface proteins during their post-translational maturation. In the brain, PSA modulates distances between cells and controls the plasticity of the nervous system. In the hypothalamus, PSA is involved in many aspects of energy balance including food intake, osmoregulation, circadian rhythm, and sleep. In this work, we investigated the role of hypothalamic PSA in the regulation of plasma cholesterol levels and distribution. We report that HFD consumption in mice rapidly increased plasma cholesterol, including VLDL, LDL, and HDL-cholesterol. Although plasma VLDL-cholesterol was normalized withi…

The Severity of Acute Stress Is Represented by Increased Synchronous Activity and Recruitment of Hypothalamic CRH Neurons

2016

The hypothalamo-pituitary-adrenocortical (HPA) axis regulates stress physiology and behavior. To achieve an optimally tuned adaptive response, it is critical that the magnitude of the stress response matches the severity of the threat. Corticotropin-releasing hormone (CRH) released from the paraventricular nucleus of the hypothalamus is a major regulator of the HPA axis. However, how CRH-producing neurons in an intact animal respond to different stressor intensities is currently not known. Using two-photon calcium imaging on intact larval zebrafish, we recorded the activity of CRH cells, while the larvae were exposed to stressors of varying intensity. By combining behavioral and physiologic…

2017

Perinatal maternal consumption of energy dense food increases the risk of obesity in children. This is associated with an overconsumption of palatable food that is consumed for its hedonic property. The underlying mechanism that links perinatal maternal diet and offspring preference for fat is still poorly understood. In the present study we aim at studying the influence of maternal high-fat/ high-sugar diet feeding (western-diet, WD) during gestation and lactation on the reward pathways controlling feeding in the rat offspring from birth to sexual maturity. We performed a longitudinal follow-up of WD and Control offspring at three critical time periods (childhood, adolescence and adulthood…

Glucose and hypothalamic astrocytes: More than a fueling role?

2015

Brain plays a central role in energy homeostasis continuously integrating numerous peripheral signals such as circulating nutrients, and in particular blood glucose level, a variable that must be highly regulated. Then, the brain orchestrates adaptive responses to modulate food intake and peripheral organs activity in order to achieve the fine tuning of glycemia. More than fifty years ago, the presence of glucose-sensitive neurons was discovered in the hypothalamus, but what makes them specific and identifiable still remains disconnected from their electrophysiological signature. On the other hand, astrocytes represent the major class of macroglial cells and are now recognized to support an…

Lack of Hypothalamus Polysialylation Inducibility Correlates With Maladaptive Eating Behaviors and Predisposition to Obesity

2018

This original research article (6 p.) is part of the research topic . Specialty section: This article was submitted to Neuroenergetics, Nutrition and Brain Health, a section of the journal Frontiers in Nutrition.; International audience; High variability exists in individual susceptibility to develop overweight in an obesogenic environment and the biological underpinnings of this heterogeneity are poorly understood. In this brief report, we show in mice that the vulnerability to diet-induced obesity is associated with low level of polysialic acid-neural cell adhesion molecule (PSA-NCAM), a factor of neural plasticity, in the hypothalamus. As we previously shown that reduction of hypothalami…

Understanding the Significance of the Hypothalamic Nature of the Subthalamic Nucleus

2021

AbstractThe subthalamic nucleus (STN) is an essential component of the basal ganglia and has long been considered to be a part of the ventral thalamus. However, recent neurodevelopmental data indicated that this nucleus is of hypothalamic origin which is now commonly acknowledged. In this work, we aimed to verify whether the inclusion of the STN in the hypothalamus could influence the way we understand and conduct research on the organization of the whole ventral and posterior diencephalon. Developmental and neurochemical data indicate that the STN is part of a larger glutamatergic posterior hypothalamic region that includes the premammillary and mammillary nuclei. The main anatomic charact…

Pharmacological activation of CB2 receptors counteracts the deleterious effect of ethanol on cell proliferation in the main neurogenic zones of the a…

2015

Chronic alcohol exposure reduces endocannabinoid activity and disrupts adult neurogenesis in rodents, which results in structural and functional alterations. Cannabinoid receptor agonists promote adult neural progenitor cell (NPC) proliferation. We evaluated the protective effects of the selective CB1 receptor agonist ACEA, the selective CB2 receptor agonist JWH133 and the fatty-acid amide-hydrolase (FAAH) inhibitor URB597, which enhances endocannabinoid receptor activity, on NPC proliferation in rats with forced consumption of ethanol (10%) or sucrose liquid diets for 2 weeks. We performed immunohistochemical and stereological analyses of cells expressing the mitotic phosphorylation of his…

Central functional response to the novel peptide cannabinoid, hemopressin.

2013

Hemopressin is the first peptide ligand to be described for the CB₁ cannabinoid receptor. Hemopressin acts as an inverse agonist in vivo and can cross the blood-brain barrier to both inhibit appetite and induce antinociception. Despite being highly effective, synthetic CB₁ inverse agonists are limited therapeutically due to unwanted, over dampening of central reward pathways. However, hemopressin appears to have its effect on appetite by affecting satiety rather than reward, suggesting an alternative mode of action which might avoid adverse side effects. Here, to resolve the neuronal circuitry mediating hemopressin's actions, we have combined blood-oxygen-level-dependent, pharmacological-ch…

Chicken adaptive response to low energy diet: main role of the hypothalamic lipid metabolism revealed by a phenotypic and multi-tissue transcriptomic…

2019

AbstractBackgroundProduction conditions of layer chicken can vary in terms of temperature or diet energy content compared to the controlled environment where pure-bred selection is undertaken. The aim of this study was to better understand the long-term effects of a 15%-energy depleted diet on egg-production, energy homeostasis and metabolism via a multi-tissue transcriptomic analysis. Study was designed to compare effects of the nutritional intervention in two layer chicken lines divergently selected for residual feed intake.ResultsChicken adapted to the diet in terms of production by significantly increasing their feed intake and decreasing their body weight and body fat composition, whil…