title: Optogenetically Blocking Sharp Wave Ripple Events in Sleep Does Not Interfere with the Formation of Stable Spatial Representation in the CA1 Area of the Hippocampus.
abstract: During hippocampal sharp wave/ripple (SWR) events, previously occurring, sensory input-driven neuronal firing patterns are replayed. Such replay is thought to be important for plasticity-related processes and consolidation of memory traces. It has previously been shown that the electrical stimulation-induced disruption of SWR events interferes with learning in rodents in different experimental paradigms. On the other hand, the cognitive map theory posits that the plastic changes of the firing of hippocampal place cells constitute the electrophysiological counterpart of the spatial learning, observable at the behavioral level. Therefore, we tested whether intact SWR events occurring during the sleep/rest session after the first exploration of a novel environment are needed for the stabilization of the CA1 code, which process requires plasticity. We found that the newly-formed representation in the CA1 has the same level of stability with optogenetic SWR blockade as with a control manipulation that delivered the same amount of light into the brain. Therefore our results suggest that at least in the case of passive exploratory behavior, SWR-related plasticity is dispensable for the stability of CA1 ensembles.
authors.affiliation: Institute of Science and Technology Austria, Klosterneuburg, Austria.
authors.forename: Krisztián A
authors.initials: KA
authors.lastname: Kovács
authors.affiliation: Institute of Science and Technology Austria, Klosterneuburg, Austria.
authors.forename: Joseph
authors.initials: J
authors.lastname: O'Neill
authors.affiliation: Institute of Science and Technology Austria, Klosterneuburg, Austria.
authors.forename: Philipp
authors.initials: P
authors.lastname: Schoenenberger
authors.affiliation: Department of Psychology, University of Jyvaskyla, Jyvaskyla, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Penttonen
authors.affiliation: Institute of Science and Technology Austria, Klosterneuburg, Austria.
authors.forename: Damaris K
authors.initials: DK
authors.lastname: Ranguel Guerrero
authors.affiliation: Institute of Science and Technology Austria, Klosterneuburg, Austria.
authors.forename: Jozsef
authors.initials: J
authors.lastname: Csicsvari
mesh_terms: D000818:Animals; D019843:Archaeal Proteins / Q000235:genetics; D058256:Brain Waves / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects; D005106:Exploratory Behavior / Q000502:physiology / Q000528:radiation effects; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D009473:Neuronal Plasticity / Q000235:genetics / Q000528:radiation effects; D009474:Neurons / Q000166:cytology / Q000528:radiation effects; D062308:Optogenetics; D012890:Sleep / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D065853:Spatial Learning / Q000502:physiology* / Q000528:radiation effects; D017494:Proton Pumps
chemical_list: D019843:Archaeal Proteins; C055476:archaerhodopsin protein, Archaea; D017494:Proton Pumps