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Séminaire impromptu - Xavier Fioramonti"Cellular and molecular mechanisms of brain glucose-sensing"

Abstract :

 Xavier Fioramonti:  The brain and more particularly the hypothalamus play a critical role in the control of energy homeostasis
in controlling feeding behavior and the activity of peripheral organs through humoral and nervous regulation systems. This control relies on neurons that are capable of integrating metabolic signals including hormones (e.g. leptin, insulin and ghrelin) and nutrients (i.e. glucose, fatty and amino acids). Among them, specialized glucose-sensing neurons are able to adapt their electrical activity in response to changes in glucose level.

Our laboratory uses complementary approaches to study these neurons from the electrophysiology on brain slices, calcium imaging on hypothalamic primary cultures, up to the in vivo experimentation.

This seminar will focus on characteristics of glucose-sensing neurons such as their nature in term of neurotransmitter and the mechanisms involved in glucose detection. The role of astrocytes and astro-neuron coupling will also be discussed.a

Selected publications

  • Benani A, Hryhorczuk C, Gouazé A, Fioramonti X, Brenachot X, Guissard C, Krezymon A, Duparc T, Colom A, Nédélec E, Rigault C, Lemoine A, Gascuel J, Gerardy-Schahn R, Valet P, Knauf C, Lorsignol A, Pénicaud L. Food intake adaptation to dietary fat involves PSA-dependent rewiring of the arcuate melanocortin system in mice. J Neurosci.(2012):29;32(35):11970-9. 
  • Fioramonti X, Marsollier N, Song Z, Fakira KA, Patel RM, Brown S, Duparc T, Pica-Mendez A, Sanders NM, Knauf C, Valet P, McCrimmon RJ, Beuve A, Magnan C, Routh VH. Ventromedial hypothalamic nitric oxide production is necessary for hypoglycemia detection and counterregulation. Diabetes. (2010);59(2):519-28.
  • Fioramonti X, Contié S, Song Z, Routh VH, Lorsignol A, Pénicaud L. Characterization of glucosensing neuron subpopulations in the arcuate nucleus: integration in neuropeptide Y and pro-opio melanocortin networks? Diabetes. (2007);56(5):1219-27.
  • Fioramonti X, Lorsignol A, Taupignon A, Penicaud L. A new KATP independent mechanism involved in glucose-excited neurons of mouse arcuate nucleus. Diabetes 2004; 53: 2767-75.a