title: Regulation of persistent sodium currents by glycogen synthase kinase 3 encodes daily rhythms of neuronal excitability.
abstract: How neurons encode intracellular biochemical signalling cascades into electrical signals is not fully understood. Neurons in the central circadian clock in mammals provide a model system to investigate electrical encoding of biochemical timing signals. Here, using experimental and modelling approaches, we show how the activation of glycogen synthase kinase 3 (GSK3) contributes to neuronal excitability through regulation of the persistent sodium current (INaP). INaPexhibits a day/night difference in peak magnitude and is regulated by GSK3. Using mathematical modelling, we predict and confirm that GSK3 activation of INaPaffects the action potential afterhyperpolarization, which increases the spontaneous firing rate without affecting the resting membrane potential. Together, these results demonstrate a crucial link between the molecular circadian clock and electrical activity, providing examples of kinase regulation of electrical activity and the propagation of intracellular signals in neuronal networks.
authors.affiliation: Department of Psychiatry, University of Alabama at Birmingham, 1720 7th Avenue South, Birmingham, Alabama 35294, USA.
authors.forename: Jodi R
authors.initials: JR
authors.lastname: Paul
authors.affiliation: Department of Mathematics, University of Michigan, 530 Church Street, Ann Arbor, Michigan 48109, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: DeWoskin
authors.affiliation: Department of Psychiatry, University of Alabama at Birmingham, 1720 7th Avenue South, Birmingham, Alabama 35294, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: McMeekin
authors.affiliation: Department of Psychiatry, University of Alabama at Birmingham, 1720 7th Avenue South, Birmingham, Alabama 35294, USA.
authors.forename: Rita M
authors.initials: RM
authors.lastname: Cowell
authors.affiliation: Department of Mathematics, University of Michigan, 530 Church Street, Ann Arbor, Michigan 48109, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Forger
authors.affiliation: Department of Psychiatry, University of Alabama at Birmingham, 1720 7th Avenue South, Birmingham, Alabama 35294, USA.
authors.forename: Karen L
authors.identifier: http://orcid.org/0000-0003-3813-8577
authors.initials: KL
authors.lastname: Gamble
mesh_terms: D000200:Action Potentials / Q000235:genetics / Q000502:physiology; D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology; D003198:Computer Simulation; D005260:Female; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008954:Models, Biological; D009474:Neurons / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D018408:Patch-Clamp Techniques; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013493:Suprachiasmatic Nucleus / Q000166:cytology
chemical_list: D015222:Sodium Channels; D012964:Sodium; D038362:Glycogen Synthase Kinase 3