title: A post-burst after depolarization is mediated by group i metabotropic glutamate receptor-dependent upregulation of Ca(v)2.3 R-type calcium channels in CA1 pyramidal neurons.
abstract: Activation of group I metabotropic glutamate receptors (subtypes mGluR1 and mGluR5) regulates neural activity in a variety of ways. In CA1 pyramidal neurons, activation of group I mGluRs eliminates the post-burst afterhyperpolarization (AHP) and produces an afterdepolarization (ADP) in its place. Here we show that upregulation of Ca(v)2.3 R-type calcium channels is responsible for a component of the ADP lasting several hundred milliseconds. This medium-duration ADP is rapidly and reversibly induced by activation of mGluR5 and requires activation of phospholipase C (PLC) and release of calcium from internal stores. Effects of mGluR activation on subthreshold membrane potential changes are negligible but are large following action potential firing. Furthermore, the medium ADP exhibits a biphasic activity dependence consisting of short-term facilitation and longer-term inhibition. These findings suggest that mGluRs may dramatically alter the firing of CA1 pyramidal neurons via a complex, activity-dependent modulation of Ca(v)2.3 R-type channels that are activated during spiking at physiologically relevant rates and patterns.
authors.affiliation: Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois, United States of America.
authors.forename: Jin-Yong
authors.initials: JY
authors.lastname: Park
authors.forename: Stefan
authors.initials: S
authors.lastname: Remy
authors.forename: Juan
authors.initials: J
authors.lastname: Varela
authors.forename: Donald C
authors.initials: DC
authors.lastname: Cooper
authors.forename: Sungkwon
authors.initials: S
authors.lastname: Chung
authors.forename: Ho-Won
authors.initials: HW
authors.lastname: Kang
authors.forename: Jung-Ha
authors.initials: JH
authors.lastname: Lee
authors.forename: Nelson
authors.initials: N
authors.lastname: Spruston
mesh_terms: D000200:Action Potentials; D000818:Animals; D020908:Calcium Channels, R-Type / Q000502:physiology*; D027682:Cation Transport Proteins / Q000502:physiology*; D005260:Female; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology*; D015854:Up-Regulation / Q000502:physiology*; D014981:Xenopus
chemical_list: C423009:CACNA1E protein, human; D020908:Calcium Channels, R-Type; D027682:Cation Transport Proteins; D018094:Receptors, Metabotropic Glutamate; D008734:Methoxyhydroxyphenylglycol; C010117:3,4-dihydroxyphenylglycol