A5041584947- Ion channel regulation and function
- Neuroscience and Neuropharmacology Research
- Receptor Mechanisms and Signaling
- Nicotinic Acetylcholine Receptors Study
- Connexins and lens biology
- Neuroendocrine regulation and behavior
- Stress Responses and Cortisol
- Neurobiology and Insect Physiology Research
- Neural dynamics and brain function
- Neuropeptides and Animal Physiology
- Protein Kinase Regulation and GTPase Signaling
- Hypothalamic control of reproductive hormones
- Neuroscience and Neural Engineering
- Photoreceptor and optogenetics research
- Pancreatic function and diabetes
- Adipose Tissue and Metabolism
- Heat shock proteins research
- Cellular transport and secretion
- Growth Hormone and Insulin-like Growth Factors
- Nitric Oxide and Endothelin Effects
- Estrogen and related hormone effects
- Ion Transport and Channel Regulation
- 14-3-3 protein interactions
- Gut microbiota and health
- Regulation of Appetite and Obesity
Inserm
2012-2024
Centre National de la Recherche Scientifique
2012-2024
Université d'Angers
2010-2024
Université de Montpellier
2008-2024
Institut de Génomique Fonctionnelle
2008-2024
Laboratoire d'Excellence Canaux Ioniques d'Intérêt Thérapeutique
2019-2023
Fondation pour la Recherche Médicale
2010
Ministère de l’Enseignement Supérieur et de la Recherche
2010
Ministère de l'Enseignement Superieur et de la Recherche
2010
Genomics (United Kingdom)
2010
1. Excitatory synaptic transmission between pairs of monosynaptically coupled pyramidal cells was examined in rat hippocampal slice cultures. Action potentials were elicited single CA3 impaled with microelectrodes and unitary excitatory postsynaptic currents (EPSCs) recorded whole‐cell voltage‐clamped CA1 or cells. 2. The amplitude successive EPSCs response to action varied. altered by adenosine changes the [Mg2+]/[CA2+] ratio. We conclude that triggered release multiple quanta glutamate. 3....
All higher life forms critically depend on hormones being rhythmically released by the anterior pituitary. The proper functioning of this master gland is dynamically controlled a complex set regulatory mechanisms that ultimately determine fine tuning excitable endocrine cells, all them heterogeneously distributed throughout gland. Here, we provide evidence for an intrapituitary communication system which information transferred via network nonendocrine folliculostellate (FS) cells. Local...
We have characterized a cationic membrane conductance activated by metabotropic glutamatergic and muscarinic cholinergic agonists in CA3 neurons hippocampal slice cultures using the patch-clamp technique. When potassium concentration superfusing fluid was raised above 5 mM, biphasic current observed cells held at -60 mV response to stimulation of postsynaptic glutamate receptors (mGluRs) with 1S,3R-ACPD (50 microM) or methacholine (MCh, microM). The initial inward component due an increase...
1. Paired intracellular recordings were made in rat hippocampal slice cultures, with the use of either sharp microelectrodes or whole cell configuration patch-clamp technique. Unitary synaptic connections studied between pyramidal and nonpyramidal cells within areas CA1 CA3. 2. Monosynaptic excitatory responses CA3 neurons found 56% pairs (n = 91, 28 postsynaptic cells). from a to observed 76% 125, 26 cells), but only 8% 13, 13 16% CA1/CA1 25, 10 3. Disynaptic inhibition was commonly (43%),...
Selenoproteins contain the essential trace element selenium, deficiency of which is associated with cancer or accelerated aging. Although selenoproteins are thought to be instrumental for effects biological function many these proteins remains unknown. Here, we studied role selenoprotein T (SelT), a selenocysteine (Sec) -containing protein no known function, have identified as novel target gene neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) during PC12 cell...
1. Effects of 1S,3R‐1‐aminocyclopentane‐1,3‐dicarboxylate (1S,3R‐ACPD) acting at metabotropic glutamate receptors (mGluRs), and methacholine (MCh), cholinergic muscarinic receptors, were investigated in CA3 neurones hippocampal slice cultures using the patch‐clamp technique. 2. Both 1S,3R‐ACPD (10 microM) MCh (0.5 activated an inward current associated with a decrease membrane conductance. The was observed when slow calcium‐dependent after‐hyperpolarizing (IAHP) voltage‐dependent (IM) not...
The exchange factor directly activated by cAMP (Epac) is a newly discovered direct target for and guanine-nucleotide the small GTPase Rap. Little known about neuronal functions of Epac. Here we show that activation Epac specific analogs or pituitary adenylate cyclase-activating polypeptide induces potent Ca 2+ -sensitive big K + channel, slight membrane hyperpolarization, increased after-hyperpolarization in cultured cerebellar granule cells. These effects involve Rap p38 MAPK, which...
In order to define the differences in distribution of cytosolic free Ca2+ ([Ca2+]i) pancreatic beta-cells stimulated with fuel secretagogue glucose or Ca(2+)-mobilizing agents carbachol and ATP, we applied digital video imaging loaded fura-2.83% cells responded an increase [Ca2+]i after a latency 117 +/- 24 s (mean S.E., 85 cells). Of these cells, 16% showed slow wave oscillations (frequency 0.35/min). assess relationship between membrane potential rise, image analysis perforated patch-clamp...
Spontaneous and CRF-stimulated changes in the cytosolic free calcium concentration ([Ca2+]i) were studied two types of corticotrophs: 1) cultured human ACTH-secreting pituitary adenoma cells (hACTH cells), 2) identified small ovoid corticotrophs from normal rat pituitaries. [Ca2+]i was monitored individual by dual emission microspectrofluorimetry using indo-1 as intracellular fluorescent Ca2+ probe. In hACTH cells, measurements carried out combination with electrophysiological recordings...
Ghrelin targets the arcuate nucleus, from where growth hormone releasing (GHRH) neurones trigger GH secretion. This hypothalamic nucleus also contains neuropeptide Y (NPY) neurons which play a master role in effect of ghrelin on feeding. Interestingly, connections between NPY and GHRH have been reported, leading to hypothesis that axis feeding circuits might be co-regulated by ghrelin.Here, we show stimulates firing rate identified neurons, transgenic GHRH-GFP mice. stimulation is prevented...
An increase in circulating adrenal catecholamine levels constitutes one of the mechanisms whereby organisms cope with stress. Accordingly, stimulus-secretion coupling within stressed medullary tissue undergoes persistent remodeling. In particular, cholinergic synaptic neurotransmission between splanchnic nerve terminals and chromaffin cells is upregulated rats. Since transmission mainly supported by activation postsynaptic neuronal acetylcholine nicotinic receptors (nAChRs), we focused our...
Mouse chromaffin cells (MCCs) of the adrenal medulla possess fast-inactivating Nav channels whose availability alters spontaneous action potential firing patterns and Ca(2+)-dependent secretion catecholamines. Here, we report MCCs expressing large densities neuronal Nav1.3 Nav1.7 that carry little or no subthreshold pacemaker currents can be slowly inactivated by 50% upon slight membrane depolarization. Reducing Nav1.3/Nav1.7 tetrodotoxin sustained depolarization near rest leads to a switch...
In adrenal chromaffin cells, a rise in cytosolic calcium concentration ([Ca(2+)]i) is key event the triggering of catecholamine exocytosis after splanchnic nerve activation. Action potential- or nicotine-induced [Ca(2+)]i transients are well described individual but whether they remain spatially confined to stimulated cell propagate adjacent cells not yet known. To address this issue, spatiotemporal organization electrical and associated Ca(2+) events between was investigated using...
Abstract The atypical chemokine receptor 3 (ACKR3) plays a pivotal role in directing the migration of various cellular populations and its over-expression tumors promotes cell proliferation invasiveness. intracellular signaling pathways transducing ACKR3-dependent effects remain poorly characterized, an issue we addressed by identifying interactome ACKR3. Here, report that recombinant ACKR3 expressed HEK293T cells recruits gap junction protein Connexin 43 (Cx43). Cx43 are co-expressed mouse...
We investigated the organization of spontaneous rises in cytosolic free Ca2+ concentration ([Ca2+] i) due to electrical activity acute pituitary slices. Real time confocal imaging revealed that 73% cells generated fast peaking [Ca2+] i transients. Strikingly, groups apposing enhanced their synchrony with a speed coactivation >1,000 μm/s. Single-cell injection Neurobiotin or Lucifer yellow labeled clusters cells, which corresponded coactive cells. Halothane, gap junction blocker, markedly...
An increase in circulating catecholamine levels represents one of the mechanisms whereby organisms cope with stress. In periphery, catecholamines mainly originate from sympathoadrenal system. As we reported, addition to central control through cholinergic innervation, a local gap junction-delineated route between adrenal chromaffin cells contributes exocytosis. Here, investigated whether this intercellular communication is modified when hormonal demand increased as observed during cold Our...