Search results for "Arcuate nucleu"
showing 10 items of 19 documents
The maternal hormone in the male brain: Sexually dimorphic distribution of prolactin signalling in the mouse brain.
2018
Research of the central actions of prolactin is highly focused on females, but this hormone has also documented roles in male physiology and behaviour. Here, we provide the first description of the pattern of prolactin-derived signalling in the male mouse brain, employing the immunostaining of phosphorylated signal transducer and activator of transcription 5 (pSTAT5) after exogenous prolactin administration. Next, we explore possible sexually dimorphic differences by comparing pSTAT5 immunoreactivity in prolactin-supplemented males and females. We also assess the role of testosterone in the regulation of central prolactin signalling in males by comparing intact with castrated prolactin-supp…
Developmental programming of somatic growth, behavior and endocannabinoid metabolism by variation of early postnatal nutrition in a cross-fostering m…
2017
Background Nutrient deprivation during early development has been associated with the predisposition to metabolic disorders in adulthood. Considering its interaction with metabolism, appetite and behavior, the endocannabinoid (eCB) system represents a promising target of developmental programming. Methods By cross-fostering and variation of litter size, early postnatal nutrition of CB6F1-hybrid mice was controlled during the lactation period (3, 6, or 10 pups/mother). After weaning and redistribution at P21, all pups received standard chow ad libitum. Gene expression analyses (liver, visceral fat, hypothalamus) were performed at P50, eCB concentrations were determined in liver and visceral …
Centrifugal projections to the main olfactory bulb revealed by trans‐synaptic retrograde tracing in mice
2020
A wide range of evidence indicates that olfactory perception is strongly involved in food intake. However, the polysynaptic circuitry linking the brain areas involved in feeding behavior to the olfactory regions is not well known. The aim of this article was to examine such circuits. Thus, we described, using hodological tools such as transsynaptic viruses (PRV152) transported in a retrograde manner, the long-distance indirect projections (two to three synapses) onto the main olfactory bulb (MOB). The ß-subunit of the cholera toxin which is a monosynaptic retrograde tracer was used as a control to be able to differentiate between direct and indirect projections. Our tracing experiments show…
Sucrose self-administration and CNS activation in the rat
2011
We have previously reported that administration of insulin into the arcuate nucleus of the hypothalamus decreases motivation for sucrose, assessed by a self-administration task, in rats. Because the pattern of central nervous system (CNS) activation in association with sucrose self-administration has not been evaluated, in the present study, we measured expression of c-Fos as an index of neuronal activation. We trained rats to bar-press for sucrose, according to a fixed-ratio (FR) or progressive-ratio (PR) schedule and mapped expression of c-Fos immunoreactivity in the CNS, compared with c-Fos expression in handled controls. We observed a unique expression of c-Fos in the medial hypothalam…
Perineuronal Net Formation and the Critical Period for Neuronal Maturation in the Hypothalamic Arcuate Nucleus
2019
In leptin-deficient ob/ob mice, obesity and diabetes are associated with abnormal development of neurocircuits in the hypothalamic arcuate nucleus (ARC)1, a critical brain area for energy and glucose homoeostasis2,3. Because this developmental defect can be remedied by systemic leptin administration, but only if given before postnatal day 28, a critical period for leptin-dependent development of ARC neurocircuits has been proposed4. In other brain areas, critical-period closure coincides with the appearance of perineuronal nets (PNNs), extracellular matrix specializations that restrict the plasticity of neurons that they enmesh5. Here we report that in humans and rodents, subsets of neurons…
Fasting enhances the response of arcuate neuropeptide Y-glucose-inhibited neurons to decreased extracellular glucose
2009
0363-6143 (Print) Comparative Study In Vitro Journal Article Research Support, N.I.H., Extramural; Fasting increases neuropeptide Y (NPY) expression, peptide levels, and the excitability of NPY-expressing neurons in the hypothalamic arcuate (ARC) nucleus. A subpopulation of ARC-NPY neurons ( approximately 40%) are glucose-inhibited (GI)-type glucose-sensing neurons. Hence, they depolarize in response to decreased glucose. Because fasting enhances NPY neurotransmission, we propose that during fasting, GI neurons depolarize in response to smaller decreases in glucose. This increased excitation in response to glucose decreases would increase NPY-GI neuronal excitability and enhance NPY neurotr…
The LepR-mediated leptin transport across brain barriers controls food reward
2018
Objective Leptin is a key hormone in the control of appetite and body weight. Predominantly produced by white adipose tissue, it acts on the brain to inhibit homeostatic feeding and food reward. Leptin has free access to circumventricular organs, such as the median eminence, but entry into other brain centers is restricted by the blood–brain and blood–CSF barriers. So far, it is unknown for which of its central effects leptin has to penetrate brain barriers. In addition, the mechanisms mediating the transport across barriers are unclear although high expression in brain barriers suggests an important role of the leptin receptor (LepR). Methods We selectively deleted LepR in brain endothelia…
Transient Receptor Potential Canonical 3 (TRPC3) Channels Are Required for Hypothalamic Glucose Detection and Energy Homeostasis
2017
Fil: Chrétien, Chloé. University of Bourgogne Franche-Comté. Institut National de la Recherche Agronomique. Centre des Sciences du Goût et de l’Alimentation; France Fil: Fenech, Claire. University of Bourgogne Franche-Comté. Institut National de la Recherche Agronomique. Centre des Sciences du Goût et de l’Alimentation; France Fil: Liénard, Fabienne. University of Bourgogne Franche-Comté. Institut National de la Recherche Agronomique. Centre des Sciences du Goût et de l’Alimentation; France Fil: Grall, Sylvie. University of Bourgogne Franche-Comté. Institut National de la Recherche Agronomique. Centre des Sciences du Goût et de l’Alimentation; France Fil: Chevalier, Charlène. University of …
Importance of mitochondrial dynamin-related protein 1 in hypothalamic glucose sensitivity in rats.
2012
International audience; AIMS: Hypothalamic mitochondrial reactive oxygen species (mROS)-mediated signaling has been recently shown to be involved in the regulation of energy homeostasis. However, the upstream signals that control this mechanism have not yet been determined. Here, we hypothesize that glucose-induced mitochondrial fission plays a significant role in mROS-dependent hypothalamic glucose sensing. RESULTS: Glucose-triggered translocation of the fission protein dynamin-related protein 1 (DRP1) to mitochondria was first investigated in vivo in hypothalamus. Thus, we show that intracarotid glucose injection induces the recruitment of DRP1 to VMH mitochondria in vivo. Then, expressio…
Hypothalamic Astroglial Connexins are Required for Brain Glucose Sensing-Induced Insulin Secretion
2014
Supplementary Information accompanies the paper on the Journal of Cerebral Blood Flow & Metabolism website; Hypothalamic glucose detection participates in maintaining glycemic balance, food intake, and thermogenesis. Although hypothalamic neurons are the executive cells involved in these responses, there is increasing evidence that astrocytes participate in glucose sensing (GS); however, it is unknown whether astroglial networking is required for glucose sensitivity. Astroglial connexins 30 and 43 (Cx30 and Cx43) form hexameric channels, which are apposed in gap junctions, allowing for the intercellular transfer of small molecules such as glucose throughout the astroglial networks. Here, we…