{"abstract":[{"text":"Epilepsy affects about 50 to 65 million people globally. It summarizes a spectrum of neurological\r\ndisorders that have in common a hyperactivity of the neuronal network resulting in seizures. A common\r\nassumption is that an imbalance between neuronal excitation and inhibition is a key mechanism in\r\nseizure generation and epileptogeneisis. In at least one-third of the patients, current therapies have\r\nproven unsuccessful in treating seizure progression. One potential reason could be that the therapies\r\nonly focus on neurons. Recent studies suggest that neuronal hyperactivity causes a microglial\r\nresponse, which reinstates brain homeostasis. Additionally, interactions between microglia and neurons\r\nhave been shown to inhibit neuronal firing and dampen seizure activity. However, the exact relationship\r\nbetween microglia and seizure progression in epilepsy is yet to be elucidated. A main bottleneck is that\r\nseveral studies investigate microglia dynamics in ex vivo slice models, which can severely affect the\r\nmicroglia dynamics due to their rapid response to environmental changes. On the other hand, in vivo\r\nstudies focus mostly on behavior characterization of the epileptic seizure phenotype and their long-term\r\nconsequences on microglia activity leaving out the direct consequences of acute seizure activity on\r\nmicroglia dynamics.\r\nHere, we perform a pilot study to combine electroencephalography (EEG) and in vivo live imaging to\r\ndirectly monitor and correlate the onset of seizure activity with microglia response. To induce seizures,\r\nwe take advantage of the kainic acid (KA) model, which represents similar neuropathological and\r\nelectroencephalographic features seen in human patients with temporal lobe epilepsy (TLE). After\r\nconfirmation of induction of the seizure and microglia activity in the hippocampus as a focal point, we\r\ninvestigated whether these changes also reached the primary visual cortex (V1) as a secondary\r\ngeneralized seizure activity. Indeed, we found that microglia changed their morphology at high doses\r\nof KA in the V1. Next, we optimized each of the two methodological components: for the EEG recording,\r\nour initial attempts under the microscope suffered from extensive electrical noise, which overlaid the\r\nactual signal. Thus, we built a customized Faraday-cage and confirmed that the signal-to-noise ratio\r\nwas sufficiently reduced to be able to record brain oscillatory activity. For the in vivo live imaging of\r\nmicroglia, we had to optimize the imaging parameters, so that we would be able to detect microglial\r\nprocesses in a sufficient resolution to track their process changes. Finally, we combined both\r\nmethodologies with the KA model. We confirmed that KA induced seizure activity and found first\r\nindication that those correlate with microglia volume changes.\r\nOverall, we have developed a first methodological approach, which allows the analysis of the acute\r\neffects of seizure onset on microglia. Future studies will have to continue to optimize the drift during\r\nimaging recording and the post-image analysis. ","lang":"eng"}],"degree_awarded":"MS","article_processing_charge":"No","has_accepted_license":"1","date_created":"2024-05-02T08:31:38Z","year":"2024","ddc":["570"],"license":"https://creativecommons.org/licenses/by/4.0/","type":"dissertation","publication_status":"published","supervisor":[{"orcid":"0000-0001-8635-0877","first_name":"Sandra","full_name":"Siegert, Sandra","id":"36ACD32E-F248-11E8-B48F-1D18A9856A87","last_name":"Siegert"}],"corr_author":"1","date_updated":"2025-05-08T09:45:00Z","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)"},"file_date_updated":"2025-05-02T22:30:04Z","OA_place":"repository","month":"05","alternative_title":["ISTA Master's Thesis"],"acknowledged_ssus":[{"_id":"Bio"},{"_id":"LifeSc"},{"_id":"PreCl"}],"publication_identifier":{"issn":["2791-4585"]},"oa_version":"Published Version","status":"public","title":"Investigating acute microglia response to seizure activity in vivo: Combining 2-Photon imaging and EEG recording","day":"02","_id":"15352","file":[{"embargo":"2025-05-02","date_updated":"2025-05-02T22:30:04Z","file_id":"15354","checksum":"095817a6c944954ac3f277e547031a33","date_created":"2024-05-02T12:26:13Z","content_type":"application/pdf","creator":"cchlebak","access_level":"open_access","file_name":"Murmann_Thesis_final_2024_2.pdf","relation":"main_file","file_size":5936142},{"file_id":"15355","date_updated":"2025-05-02T22:30:04Z","checksum":"43b632255372973a437ac87739cfd4db","embargo_to":"open_access","access_level":"closed","file_name":"Murmann_Thesis_final_2024.zip","creator":"cchlebak","date_created":"2024-05-02T12:37:56Z","content_type":"application/x-zip-compressed","file_size":20645510,"relation":"source_file"}],"department":[{"_id":"SaSi"},{"_id":"GradSch"}],"publisher":"Institute of Science and Technology Austria","citation":{"mla":"Murmann, Julie Stefanie. <i>Investigating Acute Microglia Response to Seizure Activity in Vivo: Combining 2-Photon Imaging and EEG Recording</i>. Institute of Science and Technology Austria, 2024, doi:<a href=\"https://doi.org/10.15479/at:ista:15352\">10.15479/at:ista:15352</a>.","ama":"Murmann JS. Investigating acute microglia response to seizure activity in vivo: Combining 2-Photon imaging and EEG recording. 2024. doi:<a href=\"https://doi.org/10.15479/at:ista:15352\">10.15479/at:ista:15352</a>","apa":"Murmann, J. S. (2024). <i>Investigating acute microglia response to seizure activity in vivo: Combining 2-Photon imaging and EEG recording</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/at:ista:15352\">https://doi.org/10.15479/at:ista:15352</a>","chicago":"Murmann, Julie Stefanie. “Investigating Acute Microglia Response to Seizure Activity in Vivo: Combining 2-Photon Imaging and EEG Recording.” Institute of Science and Technology Austria, 2024. <a href=\"https://doi.org/10.15479/at:ista:15352\">https://doi.org/10.15479/at:ista:15352</a>.","short":"J.S. Murmann, Investigating Acute Microglia Response to Seizure Activity in Vivo: Combining 2-Photon Imaging and EEG Recording, Institute of Science and Technology Austria, 2024.","ieee":"J. S. Murmann, “Investigating acute microglia response to seizure activity in vivo: Combining 2-Photon imaging and EEG recording,” Institute of Science and Technology Austria, 2024.","ista":"Murmann JS. 2024. Investigating acute microglia response to seizure activity in vivo: Combining 2-Photon imaging and EEG recording. Institute of Science and Technology Austria."},"oa":1,"date_published":"2024-05-02T00:00:00Z","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","page":"54","author":[{"first_name":"Julie Stefanie","full_name":"Murmann, Julie Stefanie","last_name":"Murmann","id":"1d390868-f128-11eb-9611-a0ca5f7833b5"}],"language":[{"iso":"eng"}],"doi":"10.15479/at:ista:15352"}