title: Axonal Filtering Allows Reliable Output during Dendritic Plateau-Driven Complex Spiking in CA1 Neurons.
abstract: In CA1 pyramidal neurons, correlated inputs trigger dendritic plateau potentials that drive neuronal plasticity and firing rate modulation. Given the strong electrotonic coupling between soma and axon, the >25 mV depolarization associated with the plateau could propagate through the axon to influence action potential initiation, propagation, and neurotransmitter release. We examined this issue in brain slices, awake mice, and a computational model. Despite profoundly inactivating somatic and proximal axon Na(+) channels, plateaus evoked action potentials that recovered to full amplitude in the distal axon (>150 μm) and triggered neurotransmitter release similar to regular spiking. This effect was due to strong attenuation of plateau depolarizations by axonal K(+) channels, allowing full axon repolarization and Na(+) channel deinactivation. High-pass filtering of dendritic plateaus by axonal K(+) channels should thus enable accurate transmission of gain-modulated firing rates, allowing neuronal firing to be efficiently read out by downstream regions as a simple rate code.
authors.affiliation: HHMI Janelia Research Campus, Ashburn, VA 20147, USA. Electronic address: apostolidesp@janelia.hhmi.org.
authors.forename: Pierre F
authors.initials: PF
authors.lastname: Apostolides
authors.affiliation: HHMI Janelia Research Campus, Ashburn, VA 20147, USA.
authors.forename: Aaron D
authors.initials: AD
authors.lastname: Milstein
authors.affiliation: HHMI Janelia Research Campus, Ashburn, VA 20147, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Grienberger
authors.affiliation: HHMI Janelia Research Campus, Ashburn, VA 20147, USA.
authors.forename: Katie C
authors.initials: KC
authors.lastname: Bittner
authors.affiliation: HHMI Janelia Research Campus, Ashburn, VA 20147, USA.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Magee
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology*; D055592:Biophysical Phenomena; D056547:CA1 Region, Hippocampal / Q000166:cytology*; D002118:Calcium / Q000378:metabolism; D000075402:Channelrhodopsins; D003198:Computer Simulation; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D017966:Pyramidal Cells / Q000166:cytology* / Q000502:physiology*; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D014851:Wakefulness
chemical_list: D000075402:Channelrhodopsins; D026902:Potassium Channel Blockers; D026941:Sodium Channel Blockers; D013779:Tetrodotoxin; D002118:Calcium