• Christophe Varin, Armelle Rancillac, Hélène Geoffroy, Sébastien Arthaud, Patrice Fort, and Thierry Gallopin.
• Brain Plasticity Unit, Sleep Neuronal Networks Team, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8249, 75005 Paris, France, Ecole Supérieure de Physique et de Chimie Industrielles ParisTech, 75005 Paris, France, Physiopathologie des Réseaux Neuronaux Responsables du Cycle Veille-Sommeil Team, INSERM, U1028, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5292, Lyon Neuroscience Research Center, 69372 Lyon, France, and University Lyon 1, 69000 Lyon, France.
• J. Neurosci. 2015 Jul 8;35(27):9900-11.

UnlabelledSleep-active neurons located in the ventrolateral preoptic nucleus (VLPO) play a crucial role in the induction and maintenance of slow-wave sleep (SWS). However, the cellular and molecular mechanisms responsible for their activation at sleep onset remain poorly understood. Here, we test the hypothesis that a rise in extracellular glucose concentration in the VLPO can promote sleep by increasing the activity of sleep-promoting VLPO neurons. We find that infusion of a glucose concentration into the VLPO of mice promotes SWS and increases the density of c-Fos-labeled neurons selectively in the VLPO. Moreover, we show in patch-clamp recordings from brain slices that VLPO neurons exhibiting properties of sleep-promoting neurons are selectively excited by glucose within physiological range. This glucose-induced excitation implies the catabolism of glucose, leading to a closure of ATP-sensitive potassium (KATP) channels. The extracellular glucose concentration monitors the gating of KATP channels of sleep-promoting neurons, highlighting that these neurons can adapt their excitability according to the extracellular energy status. Together, these results provide evidence that glucose may participate in the mechanisms of SWS promotion and/or consolidation.Significance StatementAlthough the brain circuitry underlying vigilance states is well described, the molecular mechanisms responsible for sleep onset remain largely unknown. Combining in vitro and in vivo experiments, we demonstrate that glucose likely contributes to sleep onset facilitation by increasing the excitability of sleep-promoting neurons in the ventrolateral preoptic nucleus (VLPO). We find here that these neurons integrate energetic signals such as ambient glucose directly to regulate vigilance states accordingly. Glucose-induced excitation of sleep-promoting VLPO neurons should therefore be involved in the drowsiness that one feels after a high-sugar meal. This novel mechanism regulating the activity of VLPO neurons reinforces the fundamental and intimate link between sleep and metabolism.Copyright © 2015 the authors 0270-6474/15/359900-12$15.00/0.

41 keywords...

hide…