title: Evidence for consolidation of neuronal assemblies after seizures in humans.
abstract: The establishment of memories involves reactivation of waking neuronal activity patterns and strengthening of associated neural circuits during slow-wave sleep (SWS), a process known as "cellular consolidation" (Dudai and Morris, 2013). Reactivation of neural activity patterns during waking behaviors that occurs on a timescale of seconds to minutes is thought to constitute memory recall (O'Keefe and Nadel, 1978), whereas consolidation of memory traces may be revealed and served by correlated firing (reactivation) that appears during sleep under conditions suitable for synaptic modification (Buhry et al., 2011). Although reactivation has been observed in human neuronal recordings (Gelbard-Sagiv et al., 2008; Miller et al., 2013), reactivation during sleep has not, likely because data are difficult to obtain and the effect is subtle. Seizures, however, provide intense and synchronous, yet sparse activation (Bower et al., 2012) that could produce a stronger consolidation effect if seizures activate learning-related mechanisms similar to those activated by learned tasks. Continuous wide-bandwidth recordings from patients undergoing intracranial monitoring for drug-resistant epilepsy revealed reactivation of seizure-related neuronal activity during subsequent SWS, but not wakefulness. Those neuronal assemblies that were most strongly activated during seizures showed the largest correlation changes, suggesting that consolidation selectively strengthened neuronal circuits activated by seizures. These results suggest that seizures "hijack" physiological learning mechanisms and also suggest a novel epilepsy therapy targeting neuronal dynamics during post-seizure sleep.
authors.affiliation: Department of Neurology, Division of Clinical Neurophysiology and Epilepsy, Mayo Systems Electrophysiology Laboratory, and bower.mark@mayo.edu.
authors.forename: Mark R
authors.identifier: http://orcid.org/0000-0002-9916-7438
authors.initials: MR
authors.lastname: Bower
authors.affiliation: Department of Neurology, Division of Clinical Neurophysiology and Epilepsy, Mayo Systems Electrophysiology Laboratory, and.
authors.forename: Matt
authors.initials: M
authors.lastname: Stead
authors.affiliation: Department of Neurologic Surgery, Division of Clinical Neurophysiology and Epilepsy, Mayo Systems Electrophysiology Laboratory, and.
authors.forename: Regina S
authors.initials: RS
authors.lastname: Bower
authors.affiliation: Department of Neurology, Division of Clinical Neurophysiology and Epilepsy, Mayo Systems Electrophysiology Laboratory, and.
authors.forename: Michal T
authors.initials: MT
authors.lastname: Kucewicz
authors.affiliation: Department of Neurology, Division of Clinical Neurophysiology and Epilepsy, Mayo Systems Electrophysiology Laboratory, and St. Anne's Hospital, International Center for Research Consortium, 656 91 Brno, Czech Republic.
authors.forename: Vlastimil
authors.identifier: http://orcid.org/0000-0002-2815-3442
authors.initials: V
authors.lastname: Sulc
authors.affiliation: Department of Neurology, Division of Clinical Neurophysiology and Epilepsy, Mayo Systems Electrophysiology Laboratory, and St. Anne's Hospital, International Center for Research Consortium, 656 91 Brno, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Cimbalnik
authors.affiliation: Department of Neurology, Division of Clinical Neurophysiology and Epilepsy, Mayo Systems Electrophysiology Laboratory, and.
authors.forename: Benjamin H
authors.initials: BH
authors.lastname: Brinkmann
authors.affiliation: Department of Neurology, Division of Clinical Neurophysiology and Epilepsy, Mayo Systems Electrophysiology Laboratory, and.
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Vasoli
authors.affiliation: Departments of Medicine and Neurology, Cognitive Neurophysiology Laboratory and Center for Sleep Medicine, Mayo Clinic, Rochester, Minnesota 55905, and.
authors.forename: Erik K
authors.identifier: http://orcid.org/0000-0002-2833-8826
authors.initials: EK
authors.lastname: St Louis
authors.affiliation: Department of Neurologic Surgery.
authors.forename: Fredric B
authors.initials: FB
authors.lastname: Meyer
authors.affiliation: Department of Neurologic Surgery.
authors.forename: W Richard
authors.identifier: http://orcid.org/0000-0003-1301-4009
authors.initials: WR
authors.lastname: Marsh
authors.affiliation: Department of Neurology, Division of Clinical Neurophysiology and Epilepsy, Mayo Systems Electrophysiology Laboratory, and.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Worrell
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D009474:Neurons / Q000502:physiology*; D012640:Seizures / Q000503:physiopathology*; D012890:Sleep / Q000502:physiology*; D055815:Young Adult
keywords: consolidation; epilepsy; learning; memory; neural assemblies; seizures