--- _id: '3538' abstract: - lang: eng text: How seizures start is a major question in epilepsy research. Preictal EEG changes occur in both human patients and animal models, but their underlying mechanisms and relationship with seizure initiation remain unknown. Here we demonstrate the existence, in the hippocampal CA1 region, of a preictal state characterized by the progressive and global increase in neuronal activity associated with a widespread buildup of low-amplitude high-frequency activity (HFA) (> 100 Hz) and reduction in system complexity. HFA is generated by the firing of neurons, mainly pyramidal cells, at much lower frequencies. Individual cycles of HFA are generated by the near-synchronous (within similar to 5 ms) firing of small numbers of pyramidal cells. The presence of HFA in the low-calcium model implicates nonsynaptic synchronization; the presence of very similar HFA in the high-potassium model shows that it does not depend on an absence of synaptic transmission. Immediately before seizure onset, CA1 is in a state of high sensitivity in which weak depolarizing or synchronizing perturbations can trigger seizures. Transition to seizure is characterized by a rapid expansion and fusion of the neuronal populations responsible for HFA, associated with a progressive slowing of HFA, leading to a single, massive, hypersynchronous cluster generating the high-amplitude low-frequency activity of the seizure. author: - first_name: Premysl full_name: Jiruska, Premysl last_name: Jiruska - first_name: Jozsef L full_name: Csicsvari, Jozsef L id: 3FA14672-F248-11E8-B48F-1D18A9856A87 last_name: Csicsvari orcid: 0000-0002-5193-4036 - first_name: Andrew full_name: Powell, Andrew last_name: Powell - first_name: John full_name: Fox, John last_name: Fox - first_name: Wei full_name: Chang, Wei last_name: Chang - first_name: Martin full_name: Vreugdenhil, Martin last_name: Vreugdenhil - first_name: Xiaoli full_name: Li, Xiaoli last_name: Li - first_name: Milan full_name: Palus, Milan last_name: Palus - first_name: Alejandro full_name: Bujan, Alejandro last_name: Bujan - first_name: Richard full_name: Dearden, Richard last_name: Dearden - first_name: John full_name: Jefferys, John last_name: Jefferys citation: ama: Jiruska P, Csicsvari JL, Powell A, et al. High-frequency network activity, global increase in neuronal activity, and synchrony expansion precede epileptic seizures in vitro. Journal of Neuroscience. 2010;30(16):5690-5701. doi:10.1523/JNEUROSCI.0535-10.2010 apa: Jiruska, P., Csicsvari, J. L., Powell, A., Fox, J., Chang, W., Vreugdenhil, M., … Jefferys, J. (2010). High-frequency network activity, global increase in neuronal activity, and synchrony expansion precede epileptic seizures in vitro. Journal of Neuroscience. Society for Neuroscience. https://doi.org/10.1523/JNEUROSCI.0535-10.2010 chicago: Jiruska, Premysl, Jozsef L Csicsvari, Andrew Powell, John Fox, Wei Chang, Martin Vreugdenhil, Xiaoli Li, et al. “High-Frequency Network Activity, Global Increase in Neuronal Activity, and Synchrony Expansion Precede Epileptic Seizures in Vitro.” Journal of Neuroscience. Society for Neuroscience, 2010. https://doi.org/10.1523/JNEUROSCI.0535-10.2010. ieee: P. Jiruska et al., “High-frequency network activity, global increase in neuronal activity, and synchrony expansion precede epileptic seizures in vitro,” Journal of Neuroscience, vol. 30, no. 16. Society for Neuroscience, pp. 5690–5701, 2010. ista: Jiruska P, Csicsvari JL, Powell A, Fox J, Chang W, Vreugdenhil M, Li X, Palus M, Bujan A, Dearden R, Jefferys J. 2010. High-frequency network activity, global increase in neuronal activity, and synchrony expansion precede epileptic seizures in vitro. Journal of Neuroscience. 30(16), 5690–5701. mla: Jiruska, Premysl, et al. “High-Frequency Network Activity, Global Increase in Neuronal Activity, and Synchrony Expansion Precede Epileptic Seizures in Vitro.” Journal of Neuroscience, vol. 30, no. 16, Society for Neuroscience, 2010, pp. 5690–701, doi:10.1523/JNEUROSCI.0535-10.2010. short: P. Jiruska, J.L. Csicsvari, A. Powell, J. Fox, W. Chang, M. Vreugdenhil, X. Li, M. Palus, A. Bujan, R. Dearden, J. Jefferys, Journal of Neuroscience 30 (2010) 5690–5701. date_created: 2018-12-11T12:03:51Z date_published: 2010-04-21T00:00:00Z date_updated: 2021-01-12T07:44:10Z day: '21' doi: 10.1523/JNEUROSCI.0535-10.2010 extern: '1' intvolume: ' 30' issue: '16' language: - iso: eng main_file_link: - open_access: '1' url: http://www.jneurosci.org/content/30/16/5690 month: '04' oa: 1 oa_version: None page: 5690 - 5701 publication: Journal of Neuroscience publication_status: published publisher: Society for Neuroscience publist_id: '2848' quality_controlled: '1' status: public title: High-frequency network activity, global increase in neuronal activity, and synchrony expansion precede epileptic seizures in vitro type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 30 year: '2010' ...