Roles of connexins and pannexins in (neuro)endocrine physiology.

International audienceTo ensure appropriate secretion in response to organismal demand, (neuro)endocrine tissues liberate massive quantities of hormone, which act to coordinate and synchronize biological signals in distant secretory and non-secretory cell populations. Intercellular communication plays a central role in this control. With regard to molecular identity, junctional cell-cell communication is supported by connexin (Cx)-based gap junctions. In addition, connexin hemichannels, the structural precursors of gap junctions, as well as pannexin (Panx) channels have recently emerged as possible modulators of the secretory process. This review focuses on the expression of connexins and pannexins in various (neuro)endocrine tissues, including the adrenal cortex and medulla, the anterior pituitary, the endocrine hypothalamus and the pineal, thyroid and parathyroid glands. In response to a physiological or pathological situation, junctional intercellular coupling can be acutely modulated or persistently remodelled, thus offering multiple regulatory possibilities. The functional role(s) of gap junction-mediated intercellular communication in endocrine physiology, as well as the involvement of connexin/pannexin-related hemichannels are also discussed

French good practice guidelines for management of the risk of low back pain among workers exposed to manual material handling: Hierarchical strategy of risk assessment of work situations

BACKGROUND: Manual material handling remains a major cause of occupational accidents and diseases in various sectors and occupations. OBJECTIVE: This paper summarizes the main recommendations of the good practice guidelines of the French Society of Occupational Medicine for the risk assessment for back disorders in workers exposed to manual handling of loads. METHODS: The guidelines were written by a multidisciplinary working group of 24 experts, according to the Clinical Practice Guidelines method proposed by French National Health Authority, and reviewed by a multidisciplinary peer review committee of 50 experts. Recommendations were based on a large systematic review of the international literature carried out from 1990 to March 2012 and classified (Grade A, B, C or expert consensus) according to their level of evidence. RESULTS: The main recommendations are a three-level hierarchical method of risk assessment based on participatory ergonomics and suggested assessment tools that can be used routinely by professionals of occupational health, workers themselves and their supervisors. CONCLUSION: These French guidelines are intended for professionals of occupational health in charge of the prevention of low back disorders. The recommended methods are applicable to other countries than France

Beta Cell Hubs Dictate Pancreatic Islet Responses to Glucose

N.R.J. was supported by a Diabetes UK RW and JM Collins Studentship (12/0004601). J.B. was supported by a European Foundation for the Study of Diabetes (EFSD) Albert Renold Young Scientist Fellowship and a Studienstiftung des deutschen Volkes PhD Studentship. D.T. was supported by an Advanced Grant from the European Research Commission (268795). G.A.R. was supported by Wellcome Trust Senior Investigator (WT098424AIA) and Royal Society Wolfson Research Merit Awards, and by MRC Programme (MR/J0003042/1), Biological and Biotechnology Research Council (BB/J015873/1), and Diabetes UK Project (11/0004210) grants. G.A.R. and M.W. acknowledge COST Action TD1304 Zinc-Net. D.J.H. was supported by Diabetes UK R.D. Lawrence (12/0004431), EFSD/Novo Nordisk Rising Star and Birmingham Fellowships, a Wellcome Trust Institutional Support Award, and an MRC Project Grant (MR/N00275X/1) with G.A.R. D.J.H and G.A.R. were supported by Imperial Confidence in Concept (ICiC) Grants. J.F. was supported by an MRC Programme grant (MR/L02036X/1). L.P. provided human islets through collaboration with the Diabetes Research Institute, IRCCS San Raffaele Scientific Institute (Milan), within the European islet distribution program for basic research supported by JDRF (1-RSC-2014-90-I-X). P.M. and M.B. were supported by the Innovative Medicine Initiative Joint Undertaking under grant agreement no. 155005 (IMIDIA), resources of which are composed of financial contribution from the European Union’s Seventh Framework Programme (FP7/2007-2013) and EFPIA companies in kind contribution, and by the Italian Ministry of University and Research (PRIN 2010-2012). D.B. and E.B. provided human islets through the European Consortium for Islet Transplantation sponsored by JDRF (1-RSC-2014-100-I-X)

Developmental and stress-induced remodeling of cell-cell communication in the adrenal medullary tissue.

International audienceThe adrenal medullary tissue contributes to maintain body homeostasis in reaction to stressful environmental changes via the release of catecholamines into the blood circulation in response to splanchnic nerve activation. Accordingly, chromaffin cell stimulus-secretion coupling undergoes temporally restricted periods of anatomo- functional remodeling in response to prevailing hormonal requirements of the organism. The postnatal development of the adrenal medulla and response to stress are remarkable physiological situations in which the stimulus- secretion coupling is critically affected. Catecholamine secretion from rat chromaffin cells is under a dual control involving an incoming initial command arising from the sympathetic nervous system that releases acetylcholine at the splanchnic nerve terminal-chromaffin cell synapses and a local gap junction-mediated intercellular communication. Interestingly, these two communication pathways are functionally interconnected within the gland and exhibit coordinated plasticity mechanisms. This article reviews the physiological and molecular evidence that the adrenal medullary tissue displays anatomical and functional adaptative remodeling of cell-cell communications upon physiological (postnatal development) and/or physiopathological (stress) situations associated with specific needs in circulating catecholamine levels

Mutations du travail, mutations du système de santé au travail : Interrogations pour la pratique des ergonomes de SSTI ?

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Vasopressin inhibits LTP in the CA2 mouse hippocampal area.

Growing evidence points to vasopressin (AVP) as a social behavior regulator modulating various memory processes and involved in pathologies such as mood disorders, anxiety and depression. Accordingly, AVP antagonists are actually envisaged as putative treatments. However, the underlying mechanisms are poorly characterized, in particular the influence of AVP on cellular or synaptic activities in limbic brain areas involved in social behavior. In the present study, we investigated AVP action on the synapse between the entorhinal cortex and CA2 hippocampal pyramidal neurons, by using both field potential and whole-cell recordings in mice brain acute slices. Short application (1 min) of AVP transiently reduced the synaptic response, only following induction of long-term potentiation (LTP) by high frequency stimulation (HFS) of afferent fibers. The basal synaptic response, measured in the absence of HFS, was not affected. The Schaffer collateral-CA1 synapse was not affected by AVP, even after LTP, while the Schaffer collateral-CA2 synapse was inhibited. Although investigated only recently, this CA2 hippocampal area appears to have a distinctive circuitry and a peculiar role in controlling episodic memory. Accordingly, AVP action on LTP-increased synaptic responses in this limbic structure may contribute to the role of this neuropeptide in controlling memory and social behavior

Erratum to: Oxytocin Signaling in the Early Life of Mammals: Link to Neurodevelopmental Disorders Associated with ASD

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Revisiting the stimulus-secretion coupling in the adrenal medulla: role of gap junction-mediated intercellular communication.

International audienceThe current view of stimulation-secretion coupling in adrenal neuroendocrine chromaffin cells holds that catecholamines are released upon transsynaptic sympathetic stimulation mediated by acetylcholine released from the splanchnic nerve terminals. However, this traditional vertical scheme would merit to be revisited in the light of recent data. Although electrical discharges invading the splanchnic nerve endings are the major physiological stimulus to trigger catecholamine release in vivo, growing evidence indicates that intercellular chromaffin cell communication mediated by gap junctions represents an additional route by which biological signals (electrical activity, changes in intracellular Ca(2+) concentration,...) propagate between adjacent cells and trigger subsequent catecholamine exocytosis. Accordingly, it has been proposed that gap junctional communication efficiently helps synapses to lead chromaffin cell function and, in particular, hormone secretion. The experimental clues supporting this hypothesis are presented and discussed with regards to both interaction with the excitatory cholinergic synaptic transmission and physiopathology of the adrenal medulla