Hypothalamus-olfactory system crosstalk: orexin a immunostaining in mice.

Short title: Orexin in miceInternational audienceIt is well known that olfaction influences food intake, and conversely, that an individual's nutritional status modulates olfactory sensitivity. However, what is still poorly understood is the neuronal correlate of this relationship, as well as the connections between the olfactory bulb and the hypothalamus. The goal of this report is to analyze the relationship between the olfactory bulb and hypothalamus, focusing on orexin A immunostaining, a hypothalamic neuropeptide that is thought to play a role in states of sleep/wakefulness. Interestingly, orexin A has also been described as a food intake stimulator. Such an effect may be due in part to the stimulation of the olfactory bulbar pathway. In rats, orexin positive cells are concentrated strictly in the lateral hypothalamus, while their projections invade nearly the entire brain including the olfactory system. Therefore, orexin appears to be a good candidate to play a pivotal role in connecting olfactory and hypothalamic pathways. So far, orexin has been described in rats, however, there is still a lack of information concerning its expression in the brains of adult and developing mice. In this context, we revisited the orexin A pattern in adult and developing mice using immunohistological methods and confocal microscopy. Besides minor differences, orexin A immunostaining in mice shares many features with those observed in rats. In the olfactory bulb, even though there are few orexin projections, they reach all the different layers of the olfactory bulb. In contrast to the presence of orexin projections in the main olfactory bulb, almost none have been found in the accessory olfactory bulb. The developmental expression of orexin A supports the hypothesis that orexin expression only appears post-natally

O ventre sacia-se, os olhos não O suporte social em adolescentes que prosseguiram a gravidez e mulheres que recorreram a interrupção voluntária da gravidez na adolescência.

O presente artigo relata um estudo que versou sobre a temática da Gravidez na Adolescência, quer na escolha do Prosseguimento da Gravidez pela jovem, quer pela sua Interrupção Voluntária. Assim, consistiu em averiguar quais as características associadas às adolescentes que mantêm a gravidez e quais as das adolescentes que optam por interrompê-la voluntariamente e, principalmente, em aferir do Suporte Social e suas características em ambas as situaçõesThe present paper presents a study concerning adolescent pregnancy decision. Its purpose was to investigate the characteristics associated with adolescents who maintained their pregnancy and those who chose induced abortion, mainly regarding social support and its characteristics.info:eu-repo/semantics/publishedVersio

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

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 hypothalamic PSA-NCAM is sufficient to alter energy homeostasis and promote fat storage under hypercaloric pressure, inter-individual variability in hypothalamic PSA-NCAM might account for the vulnerability to diet-induced obesity. These data support the concept that reduced plasticity in brain circuits that control appetite, metabolism and body weight confers risk for eating disorders and obesity

The Discovery of a Gravitationally Lensed Supernova Ia at Redshift 2.22

We present the discovery and measurements of a gravitationally lensed supernova (SN) behind the galaxy cluster MOO J1014+0038. Based on multi-band Hubble Space Telescope and Very Large Telescope (VLT) photometry of the supernova, and VLT spectroscopy of the host galaxy, we find a 97.5% probability that this SN is a SN Ia, and a 2.5% chance of a CC SN. Our typing algorithm combines the shape and color of the light curve with the expected rates of each SN type in the host galaxy. With a redshift of 2.2216, this is the highest redshift SN Ia discovered with a spectroscopic host-galaxy redshift. A further distinguishing feature is that the lensing cluster, at redshift 1.23, is the most distant to date to have an amplified SN. The SN lies in the middle of the color and light-curve shape distributions found at lower redshift, disfavoring strong evolution to z = 2.22. We estimate an amplification due to gravitational lensing of 2.8+0.6-0.5 (1.10 +- 0.23 mag)---compatible with the value estimated from the weak-lensing-derived mass and the mass-concentration relation from LambdaCDM simulations---making it the most amplified SN Ia discovered behind a galaxy cluster

Caractérisation de mécanismes impliqués dans le contrôle de l expression du gène de la gamma-butyrobétaïne hydroxylase

La gamma-butyrobétaine hydroxylase (BBOX1) catalyse la réaction de biosynthèse de la L-carnitine, molécule impliquée dans le métabolisme des acides gras. Afin de mieux comprendre les mécanismes impliqués dans la régulation de la disponibilité de la L-carnitine dans l organisme, le contrôle de l expression du gène de la BBOX1 a été étudié. Différentes formes d ARN messagers de la BBOX1 ont été identifiées chez le rat et chez l homme, les mécanismes impliqués dans la genèse de ces ARN et leurs spécificités tissulaires ont été caractérisés. Une initiation alternative de la transcription gouvernée par plusieurs promoteurs a été identifiée chez l homme ; une maturation différentielle des transcrits impliquant plusieurs sites de polyadénylation a été caractérisée dans les deux espèces. En participant au contrôle de l expression du gène de la BBOX1 et de la synthèse de la protéine codée, ces processus contribuent à la modulation de l efficacité de la voie de biosynthèse de la L-carnitine.The gamma-butyrobetaine hydroxylase (BBOX1) catalyzes the biosynthesis of L-carnitine, a molecule involved in fatty acid metabolism. To have a better understanding of the regulation of the bioavailability of L-carnitine, the expression of the BBOX1 gene and its regulation were studied. Various forms of BBOX1 mRNA were identified in rat and in human, the mechanisms responsible for their synthesis and the tissue specificity of these mechanisms were studied. Different promoters involved in an alternative transcription initiation process were characterized in human; an alternative maturation of the RNA involving several polyadenylation sites was discovered in both species. These mechanisms are involved in the control of the expression of the BBOX1 gene and of the synthesis of the encoded protein, and thus contribute to the regulation of the efficiency of the L-carnitine biosynthesis pathway.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

Hypothalamus-Olfactory System Crosstalk: Orexin A Immunostaining in Mice

It is well known that olfaction influences food intake, and conversely, that an individual’s nutritional status modulates olfactory sensitivity. However, what is still poorly understood is the neuronal correlate of this relationship, as well as the connections between the olfactory bulb and the hypothalamus. The goal of this report is to analyze the relationship between the olfactory bulb and hypothalamus, focusing on orexin A immunostaining, a hypothalamic neuropeptide that is thought to play a role in states of sleep/wakefulness. Interestingly, orexin A has also been described as a food intake stimulator. Such an effect may be due in part to the stimulation of the olfactory bulbar pathway. In rats, orexin positive cells are concentrated strictly in the lateral hypothalamus, while their projections invade nearly the entire brain including the olfactory system. Therefore, orexin appears to be a good candidate to play a pivotal role in connecting olfactory and hypothalamic pathways. So far, orexin has been described in rats, however, there is still a lack of information concerning its expression in the brains of adult and developing mice. In this context, we revisited the orexin A pattern in adult and developing mice using immunohistological methods and confocal microscopy. Besides minor differences, orexin A immunostaining in mice shares many features with those observed in rats. In the olfactory bulb, even though there are few orexin projections, they reach all the different layers of the olfactory bulb. In contrast to the presence of orexin projections in the main olfactory bulb, almost none have been found in the accessory olfactory bulb. The developmental expression of orexin A supports the hypothesis that orexin expression only appears post-natally.This work was supported by Research grant BFU2010-15564 from the Spanish Ministry of Economy and Competitiveness (MINECO) and by INRA (National Institute for Agronomical Research) and the Burgundy Regional Council (Conseil Régional de Bourgogne).Peer reviewedPeer Reviewe

A high-fat diet increases l-carnitine synthesis through a differential maturation of the Bbox1 mRNAs.

International audiencel-carnitine is a key molecule in both mitochondrial and peroxisomal lipid metabolisms. l-carnitine is biosynthesized from gamma-butyrobetaine by a reaction catalyzed by the gamma-butyrobetaine hydroxylase (Bbox1). The aim of this work was to identify molecular mechanisms involved in the regulation of l-carnitine biosynthesis and availability. Using 3' RACE, we identified four alternatively polyadenylated Bbox1 mRNAs in rat liver. We utilized a combination of in vitro experiments using hybrid constructs containing the Bbox1 3' UTR and in vivo experiments on rat liver mRNAs to reveal specificities in the different Bbox1 mRNA isoforms, especially in terms of polyadenylation efficiency, mRNA stability and translation efficiency. This complex maturation process of the Bbox1 mRNAs in the liver was studied on rats fed a high-fat diet. High-fat diet selectively increased the level of three Bbox1 mRNA isoforms in rat liver and the alternative use of polyadenylation sites contributed to the global increase in Bbox1 enzymatic activity and l-carnitine levels. Our results show that the maturation of Bbox1 mRNAs is nutritionally regulated in the liver through a selective polyadenylation process to adjust l-carnitine biosynthesis to the energy supply

Plasticity of the melanocortin system: Determinants and possible consequences on food intake

The melanocortin system is one of the most important neuronal pathways involved in the regulation of food intake and is probably the best characterized. Agouti-related peptide (AgRP) and proopiomelanocortin (POMC) expressing neurons located in the arcuate nucleus of the hypothalamus are the key elements of this system. These two neuronal populations are sensitive to circulating molecules and receive many excitatory and inhibitory inputs from various brain areas. According to sensory and metabolic information they integrate, these neurons control different aspects of feeding behavior and orchestrate autonomic responses aimed at maintaining energy homeostasis. Interestingly, composition and abundance of pre-synaptic inputs onto arcuate AgRP and POMC neurons vary in the adult hypothalamus in response to changes in the metabolic state, a phenomenon that can be recapitulated by treatment with hormones, such as leptin or ghrelin. As described in other neuroendrocrine systems, glia might be determinant to shift the synaptic configuration of AgRP and POMC neurons. Here, we discuss the physiological outcome of the synaptic plasticity of the melanocortin system, and more particularly its contribution to the control of energy balance. The discovery of this attribute has changed how we view obesity and related disorders, and opens new perspectives for their management

Détection cérébrale du glucose, plasticité neuronale et métabolisme énergétique

National audienceEnergy intake is usually well regulated and finely adjusted to energy expenditure. This equilibrium, called energy homeostasis, is dependant in part of the central nervous system which is able to analyse the energy state of the organism by the integration of numerous signals coming from the periphery from which glucose is an important one. This review focuses on the recent advances made on the identification of cellular and molecular mechanisms, phenotype of the neurons, neuronal network and their plasticity involved in glucose sensing. For example, it is now well established that neurons responding to hypo-, hyper-glycemia and even at different concentration changes are present at least in the hypothalamus. Mechanisms involved various actors such as glucose transporters, mitochondria and signals generated by their respiratory activity (ATP, reactive oxygen species) and ion channels. A new area concerns the role of the plasticity of neuronal networks involved in the regulation of the energy metabolism. Altogether, these data should allow to define better and possibly modulate the responses associated with modifications of glycemia and in particular changes observed during various nutritional and/or metabolic pathologies

Crosstalk between hypothalamic neurons and olfactory system: a tracing and anatomo-fuctional investigation in mouse

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