--- OA_place: publisher _id: '9562' abstract: - lang: eng text: Left-right asymmetries can be considered a fundamental organizational principle of the vertebrate central nervous system. The hippocampal CA3-CA1 pyramidal cell synaptic connection shows an input-side dependent asymmetry where the hemispheric location of the presynaptic CA3 neuron determines the synaptic properties. Left-input synapses terminating on apical dendrites in stratum radiatum have a higher density of NMDA receptor subunit GluN2B, a lower density of AMPA receptor subunit GluA1 and smaller areas with less often perforated PSDs. On the other hand, left-input synapses terminating on basal dendrites in stratum oriens have lower GluN2B densities than right-input ones. Apical and basal synapses further employ different signaling pathways involved in LTP. SDS-digested freeze-fracture replica labeling can visualize synaptic membrane proteins with high sensitivity and resolution, and has been used to reveal the asymmetry at the electron microscopic level. However, it requires time-consuming manual demarcation of the synaptic surface for quantitative measurements. To facilitate the analysis of replica labeling, I first developed a software named Darea, which utilizes deep-learning to automatize this demarcation. With Darea I characterized the synaptic distribution of NMDA and AMPA receptors as well as the voltage-gated Ca2+ channels in CA1 stratum radiatum and oriens. Second, I explored the role of GluN2B and its carboxy-terminus in the establishment of input-side dependent hippocampal asymmetry. In conditional knock-out mice lacking GluN2B expression in CA1 and GluN2B-2A swap mice, where GluN2B carboxy-terminus was exchanged to that of GluN2A, no significant asymmetries of GluN2B, GluA1 and PSD area were detected. We further discovered a previously unknown functional asymmetry of GluN2A, which was also lost in the swap mouse. These results demonstrate that GluN2B carboxy-terminus plays a critical role in normal formation of input-side dependent asymmetry. acknowledged_ssus: - _id: EM-Fac alternative_title: - ISTA Thesis article_processing_charge: No author: - first_name: David full_name: Kleindienst, David id: 42E121A4-F248-11E8-B48F-1D18A9856A87 last_name: Kleindienst citation: ama: 'Kleindienst D. 2B or not 2B: Hippocampal asymmetries mediated by NMDA receptor subunit GluN2B C-terminus and high-throughput image analysis by Deep-Learning. 2021. doi:10.15479/at:ista:9562' apa: 'Kleindienst, D. (2021). 2B or not 2B: Hippocampal asymmetries mediated by NMDA receptor subunit GluN2B C-terminus and high-throughput image analysis by Deep-Learning. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:9562' chicago: 'Kleindienst, David. “2B or Not 2B: Hippocampal Asymmetries Mediated by NMDA Receptor Subunit GluN2B C-Terminus and High-Throughput Image Analysis by Deep-Learning.” Institute of Science and Technology Austria, 2021. https://doi.org/10.15479/at:ista:9562.' ieee: 'D. Kleindienst, “2B or not 2B: Hippocampal asymmetries mediated by NMDA receptor subunit GluN2B C-terminus and high-throughput image analysis by Deep-Learning,” Institute of Science and Technology Austria, 2021.' ista: 'Kleindienst D. 2021. 2B or not 2B: Hippocampal asymmetries mediated by NMDA receptor subunit GluN2B C-terminus and high-throughput image analysis by Deep-Learning. Institute of Science and Technology Austria.' mla: 'Kleindienst, David. 2B or Not 2B: Hippocampal Asymmetries Mediated by NMDA Receptor Subunit GluN2B C-Terminus and High-Throughput Image Analysis by Deep-Learning. Institute of Science and Technology Austria, 2021, doi:10.15479/at:ista:9562.' short: 'D. Kleindienst, 2B or Not 2B: Hippocampal Asymmetries Mediated by NMDA Receptor Subunit GluN2B C-Terminus and High-Throughput Image Analysis by Deep-Learning, Institute of Science and Technology Austria, 2021.' corr_author: '1' date_created: 2021-06-17T14:10:47Z date_published: 2021-06-01T00:00:00Z date_updated: 2026-07-06T13:11:44Z day: '01' ddc: - '570' degree_awarded: PhD department: - _id: GradSch - _id: RySh doi: 10.15479/at:ista:9562 file: - access_level: open_access checksum: 659df5518db495f679cb1df9e9bd1d94 content_type: application/pdf creator: dkleindienst date_created: 2021-06-17T14:03:14Z date_updated: 2022-07-02T22:30:04Z embargo: 2022-07-01 file_id: '9563' file_name: Thesis.pdf file_size: 77299142 relation: main_file - access_level: closed checksum: 3bcf63a2b19e5b6663be051bea332748 content_type: application/zip creator: dkleindienst date_created: 2021-06-17T14:04:30Z date_updated: 2022-07-02T22:30:04Z embargo_to: open_access file_id: '9564' file_name: Thesis_source.zip file_size: 369804895 relation: source_file file_date_updated: 2022-07-02T22:30:04Z fulldoi: https://doi.org/10.15479/at:ista:9562 has_accepted_license: '1' language: - iso: eng month: '06' oa: 1 oa_version: Published Version page: '124' publication_identifier: issn: - 2663-337X publication_status: published publisher: Institute of Science and Technology Austria related_material: record: - id: '9437' relation: part_of_dissertation status: public - id: '612' relation: part_of_dissertation status: public - id: '8532' relation: part_of_dissertation status: public - id: '9756' relation: part_of_dissertation status: public status: public supervisor: - first_name: Ryuichi full_name: Shigemoto, Ryuichi id: 499F3ABC-F248-11E8-B48F-1D18A9856A87 last_name: Shigemoto orcid: 0000-0001-8761-9444 title: '2B or not 2B: Hippocampal asymmetries mediated by NMDA receptor subunit GluN2B C-terminus and high-throughput image analysis by Deep-Learning' type: dissertation user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd year: '2021' ...