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 Journal Article


Author(s): Kovács, Krisztián A; O'Neill, Joseph; Schönenberger, Philipp; Penttonen, Markku; Rangel Guerrero, Dámaris K; Csicsvári, József
Article 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
Affiliation IST Austria
Abstract: During hippocampal sharp wave/ripple (SWR) events, previously occurring, sensory inputdriven 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.
Keywords: Rest; Sleep; Exploratory Behavior; plasticity; hippocampal CA1 region; spatial learning
Journal Title: PLoS One
Volume: 11
Issue 10
ISSN: 1932-6203
Publisher: Public Library of Science  
Date Published: 2016-10-01
Start Page: Article number: e0164675
Copyright Statement: CC BY 4.0
URL:
DOI: 10.1371/journal.pone.0164675
Notes: The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme (FP7/2007-2013) under REA grant agreement n° [291734] via the IST FELLOWSHIP awarded to Dr. Krisztián A. Kovács and the European Research Council starting grant (acronym: HIPECMEM Project reference: 281511) awarded to Dr. Jozsef Csicsvari. We thank Lauri Viljanto for technical help in building the ripple detector.
Open access: yes (OA journal)