--- _id: '48' abstract: - lang: eng text: 'The hippocampus is a key brain region for spatial memory and navigation and is needed at all stages of memory, including encoding, consolidation, and recall. Hippocampal place cells selectively discharge at specific locations of the environment to form a cognitive map of the space. During the rest period and sleep following spatial navigation and/or learning, the waking activity of the place cells is reactivated within high synchrony events. This reactivation is thought to be important for memory consolidation and stabilization of the spatial representations. The aim of my thesis was to directly test whether the reactivation content encoded in firing patterns of place cells is important for consolidation of spatial memories. In particular, I aimed to test whether, in cases when multiple spatial memory traces are acquired during learning, the specific disruption of the reactivation of a subset of these memories leads to the selective disruption of the corresponding memory traces or through memory interference the other learned memories are disrupted as well. In this thesis, using a modified cheeseboard paradigm and a closed-loop recording setup with feedback optogenetic stimulation, I examined how the disruption of the reactivation of specific spiking patterns affects consolidation of the corresponding memory traces. To obtain multiple distinctive memories, animals had to perform a spatial task in two distinct cheeseboard environments and the reactivation of spiking patterns associated with one of the environments (target) was disrupted after learning during four hours rest period using a real-time decoding method. This real-time decoding method was capable of selectively affecting the firing rates and cofiring correlations of the target environment-encoding cells. The selective disruption led to behavioural impairment in the memory tests after the rest periods in the target environment but not in the other undisrupted control environment. In addition, the map of the target environment was less stable in the impaired memory tests compared to the learning session before than the map of the control environment. However, when the animal relearned the task, the same map recurred in the target environment that was present during learning before the disruption. Altogether my work demonstrated that the reactivation content is important: assembly-related disruption of reactivation can lead to a selective memory impairment and deficiency in map stability. These findings indeed suggest that reactivated assembly patterns reflect processes associated with the consolidation of memory traces. ' alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: Igor full_name: Gridchyn, Igor id: 4B60654C-F248-11E8-B48F-1D18A9856A87 last_name: Gridchyn orcid: 0000-0002-1807-1929 citation: ama: Gridchyn I. Reactivation content is important for consolidation of spatial memory. 2018. doi:10.15479/AT:ISTA:th_1042 apa: Gridchyn, I. (2018). Reactivation content is important for consolidation of spatial memory. Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_1042 chicago: Gridchyn, Igor. “Reactivation Content Is Important for Consolidation of Spatial Memory.” Institute of Science and Technology Austria, 2018. https://doi.org/10.15479/AT:ISTA:th_1042. ieee: I. Gridchyn, “Reactivation content is important for consolidation of spatial memory,” Institute of Science and Technology Austria, 2018. ista: Gridchyn I. 2018. Reactivation content is important for consolidation of spatial memory. Institute of Science and Technology Austria. mla: Gridchyn, Igor. Reactivation Content Is Important for Consolidation of Spatial Memory. Institute of Science and Technology Austria, 2018, doi:10.15479/AT:ISTA:th_1042. short: I. Gridchyn, Reactivation Content Is Important for Consolidation of Spatial Memory, Institute of Science and Technology Austria, 2018. date_created: 2018-12-11T11:44:21Z date_published: 2018-08-27T00:00:00Z date_updated: 2023-09-07T12:42:44Z day: '27' ddc: - '573' degree_awarded: PhD department: - _id: JoCs doi: 10.15479/AT:ISTA:th_1042 file: - access_level: closed checksum: 7db4415e435590fa33542c7b0a0321d7 content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document creator: dernst date_created: 2019-04-08T13:36:01Z date_updated: 2021-02-11T23:30:22Z embargo_to: open_access file_id: '6236' file_name: 2018_Thesis_Gridchyn_source.docx file_size: 7666687 relation: source_file - access_level: open_access checksum: f96f3fe8979f7b1e6db6acaca962b10c content_type: application/pdf creator: dernst date_created: 2019-04-08T13:36:01Z date_updated: 2021-02-11T11:17:18Z embargo: 2019-08-29 file_id: '6237' file_name: 2018_Thesis_Gridchyn.pdf file_size: 6034153 relation: main_file file_date_updated: 2021-02-11T23:30:22Z has_accepted_license: '1' language: - iso: eng month: '08' oa: 1 oa_version: Published Version page: '104' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria publist_id: '8006' pubrep_id: '1042' status: public supervisor: - first_name: Jozsef L full_name: Csicsvari, Jozsef L id: 3FA14672-F248-11E8-B48F-1D18A9856A87 last_name: Csicsvari orcid: 0000-0002-5193-4036 title: Reactivation content is important for consolidation of spatial memory tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: dissertation user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 year: '2018' ...