title: Multiparametric characterization of neuronal subpopulations in the ventrolateral preoptic nucleus.
abstract: The characterization of neuronal properties is a necessary first step toward understanding how the ventrolateral preoptic nucleus (VLPO) neuronal network regulates slow-wave sleep (SWS). Indeed, the electrophysiological heterogeneity of VLPO neurons suggests the existence of subtypes that could differently contribute in SWS induction and maintenance. The aim of the present study was to define cell classes in the VLPO using an unsupervised clustering classification method. Electrophysiological features extracted from 289 neurons recorded in whole-cell patch-clamp allowed the identification of three main classes of VLPO neurons subdivided into five distinct subpopulations (cluster 1, 2a, 2b, 3a and 3b). The high occurrence of a low-threshold calcium spike (LTS) was one of the most distinctive features of cluster 1 and 3. Since sleep-promoting neurons are generally identified by their ability to generate an LTS and by their inhibitory response to noradrenaline (NA), 189 neurons from our dataset were also tested for this neurotransmitter. Neurons from cluster 3 were the most frequently inhibited by NA. Biocytin labeling and Neurolucida reconstructions of 112 neurons furthermore revealed a small dendritic arbor of cluster 3b neurons compared, in particular, to cluster 2b neurons. Altogether, we performed an exhaustive characterization of VLPO neuronal subtypes that is a crucial step toward a better understanding of the neuronal network within the VLPO and thereby sleep physiology.
authors.affiliation: Brain Plasticity Unit, ESPCI-ParisTech, PSL Research University, 75005, Paris, France.|CNRS, UMR 8249, 75005, Paris, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Dubourget
authors.affiliation: Brain Plasticity Unit, ESPCI-ParisTech, PSL Research University, 75005, Paris, France.|CNRS, UMR 8249, 75005, Paris, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Sangare
authors.affiliation: Brain Plasticity Unit, ESPCI-ParisTech, PSL Research University, 75005, Paris, France.|CNRS, UMR 8249, 75005, Paris, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Geoffroy
authors.affiliation: Brain Plasticity Unit, ESPCI-ParisTech, PSL Research University, 75005, Paris, France.|CNRS, UMR 8249, 75005, Paris, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Gallopin
authors.affiliation: Brain Plasticity Unit, ESPCI-ParisTech, PSL Research University, 75005, Paris, France. armelle.rancillac@college-de-france.fr.|CNRS, UMR 8249, 75005, Paris, France. armelle.rancillac@college-de-france.fr.|Armelle Rancillac, CIRB, Collège de France, CNRS UMR 7241/Inserm U1050, Paris, France. armelle.rancillac@college-de-france.fr.
authors.forename: Armelle
authors.identifier: 0000-0003-1085-5929
authors.initials: A
authors.lastname: Rancillac
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D001703:Biophysics; D016000:Cluster Analysis; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D011301:Preoptic Area / Q000166:cytology*; D012701:Serotonin / Q000494:pharmacology; D018709:Statistics, Nonparametric; D055366:Synaptic Potentials / Q000187:drug effects / Q000502:physiology*
chemical_list: D012701:Serotonin; D009638:Norepinephrine
keywords: Low-threshold calcium spike (LTS); Noradrenaline; Serotonin; Sleep-promoting neuron; VLPO; Ward’s clustering