--- _id: '1616' abstract: - lang: eng text: The hippocampus plays a key role in learning and memory. Previous studies suggested that the main types of principal neurons, dentate gyrus granule cells (GCs), CA3 pyramidal neurons, and CA1 pyramidal neurons, differ in their activity pattern, with sparse firing in GCs and more frequent firing in CA3 and CA1 pyramidal neurons. It has been assumed but never shown that such different activity may be caused by differential synaptic excitation. To test this hypothesis, we performed high-resolution whole-cell patch-clamp recordings in anesthetized rats in vivo. In contrast to previous in vitro data, both CA3 and CA1 pyramidal neurons fired action potentials spontaneously, with a frequency of ∼3–6 Hz, whereas GCs were silent. Furthermore, both CA3 and CA1 cells primarily fired in bursts. To determine the underlying mechanisms, we quantitatively assessed the frequency of spontaneous excitatory synaptic input, the passive membrane properties, and the active membrane characteristics. Surprisingly, GCs showed comparable synaptic excitation to CA3 and CA1 cells and the highest ratio of excitation versus hyperpolarizing inhibition. Thus, differential synaptic excitation is not responsible for differences in firing. Moreover, the three types of hippocampal neurons markedly differed in their passive properties. While GCs showed the most negative membrane potential, CA3 pyramidal neurons had the highest input resistance and the slowest membrane time constant. The three types of neurons also differed in the active membrane characteristics. GCs showed the highest action potential threshold, but displayed the largest gain of the input-output curves. In conclusion, our results reveal that differential firing of the three main types of hippocampal principal neurons in vivo is not primarily caused by differences in the characteristics of the synaptic input, but by the distinct properties of synaptic integration and input-output transformation. acknowledgement: "The authors thank Jose Guzman for critically reading prior versions of the manuscript. They also thank T. Asenov for\r\nengineering mechanical devices, A. Schlögl for efficient pro-gramming, F. Marr for technical assistance, and E. Kramberger for manuscript editing." article_processing_charge: No author: - first_name: Janina full_name: Kowalski, Janina id: 3F3CA136-F248-11E8-B48F-1D18A9856A87 last_name: Kowalski - first_name: Jian full_name: Gan, Jian id: 3614E438-F248-11E8-B48F-1D18A9856A87 last_name: Gan - first_name: Peter M full_name: Jonas, Peter M id: 353C1B58-F248-11E8-B48F-1D18A9856A87 last_name: Jonas orcid: 0000-0001-5001-4804 - first_name: Alejandro full_name: Pernia-Andrade, Alejandro id: 36963E98-F248-11E8-B48F-1D18A9856A87 last_name: Pernia-Andrade citation: ama: Kowalski J, Gan J, Jonas PM, Pernia-Andrade A. Intrinsic membrane properties determine hippocampal differential firing pattern in vivo in anesthetized rats. Hippocampus. 2016;26(5):668-682. doi:10.1002/hipo.22550 apa: Kowalski, J., Gan, J., Jonas, P. M., & Pernia-Andrade, A. (2016). Intrinsic membrane properties determine hippocampal differential firing pattern in vivo in anesthetized rats. Hippocampus. Wiley. https://doi.org/10.1002/hipo.22550 chicago: Kowalski, Janina, Jian Gan, Peter M Jonas, and Alejandro Pernia-Andrade. “Intrinsic Membrane Properties Determine Hippocampal Differential Firing Pattern in Vivo in Anesthetized Rats.” Hippocampus. Wiley, 2016. https://doi.org/10.1002/hipo.22550. ieee: J. Kowalski, J. Gan, P. M. Jonas, and A. Pernia-Andrade, “Intrinsic membrane properties determine hippocampal differential firing pattern in vivo in anesthetized rats,” Hippocampus, vol. 26, no. 5. Wiley, pp. 668–682, 2016. ista: Kowalski J, Gan J, Jonas PM, Pernia-Andrade A. 2016. Intrinsic membrane properties determine hippocampal differential firing pattern in vivo in anesthetized rats. Hippocampus. 26(5), 668–682. mla: Kowalski, Janina, et al. “Intrinsic Membrane Properties Determine Hippocampal Differential Firing Pattern in Vivo in Anesthetized Rats.” Hippocampus, vol. 26, no. 5, Wiley, 2016, pp. 668–82, doi:10.1002/hipo.22550. short: J. Kowalski, J. Gan, P.M. Jonas, A. Pernia-Andrade, Hippocampus 26 (2016) 668–682. date_created: 2018-12-11T11:53:03Z date_published: 2016-05-01T00:00:00Z date_updated: 2023-10-17T10:02:02Z day: '01' ddc: - '570' department: - _id: PeJo doi: 10.1002/hipo.22550 file: - access_level: open_access checksum: 284b72b12fbe15474833ed3d4549f86b content_type: application/pdf creator: system date_created: 2018-12-12T10:13:47Z date_updated: 2020-07-14T12:45:07Z file_id: '5033' file_name: IST-2016-469-v1+1_Kowalski_et_al-Hippocampus.pdf file_size: 905348 relation: main_file file_date_updated: 2020-07-14T12:45:07Z has_accepted_license: '1' intvolume: ' 26' issue: '5' language: - iso: eng month: '05' oa: 1 oa_version: Published Version page: 668 - 682 publication: Hippocampus publication_identifier: eissn: - 1098-1063 issn: - 1050-9631 publication_status: published publisher: Wiley publist_id: '5550' pubrep_id: '469' quality_controlled: '1' scopus_import: '1' status: public title: Intrinsic membrane properties determine hippocampal differential firing pattern in vivo in anesthetized rats tmp: image: /images/cc_by_nc_nd.png legal_code_url: https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) short: CC BY-NC-ND (4.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 26 year: '2016' ... --- _id: '2164' abstract: - lang: eng text: 'Neuronal ectopia, such as granule cell dispersion (GCD) in temporal lobe epilepsy (TLE), has been assumed to result from a migration defect during development. Indeed, recent studies reported that aberrant migration of neonatal-generated dentate granule cells (GCs) increased the risk to develop epilepsy later in life. On the contrary, in the present study, we show that fully differentiated GCs become motile following the induction of epileptiform activity, resulting in GCD. Hippocampal slice cultures from transgenic mice expressing green fluorescent protein in differentiated, but not in newly generated GCs, were incubated with the glutamate receptor agonist kainate (KA), which induced GC burst activity and GCD. Using real-time microscopy, we observed that KA-exposed, differentiated GCs translocated their cell bodies and changed their dendritic organization. As found in human TLE, KA application was associated with decreased expression of the extracellular matrix protein Reelin, particularly in hilar interneurons. Together these findings suggest that KA-induced motility of differentiated GCs contributes to the development of GCD and establish slice cultures as a model to study neuronal changes induced by epileptiform activity. ' author: - first_name: Xuejun full_name: Chai, Xuejun last_name: Chai - first_name: Gert full_name: Münzner, Gert last_name: Münzner - first_name: Shanting full_name: Zhao, Shanting last_name: Zhao - first_name: Stefanie full_name: Tinnes, Stefanie last_name: Tinnes - first_name: Janina full_name: Kowalski, Janina id: 3F3CA136-F248-11E8-B48F-1D18A9856A87 last_name: Kowalski - first_name: Ute full_name: Häussler, Ute last_name: Häussler - first_name: Christina full_name: Young, Christina last_name: Young - first_name: Carola full_name: Haas, Carola last_name: Haas - first_name: Michael full_name: Frotscher, Michael last_name: Frotscher citation: ama: Chai X, Münzner G, Zhao S, et al. Epilepsy-induced motility of differentiated neurons. Cerebral Cortex. 2014;24(8):2130-2140. doi:10.1093/cercor/bht067 apa: Chai, X., Münzner, G., Zhao, S., Tinnes, S., Kowalski, J., Häussler, U., … Frotscher, M. (2014). Epilepsy-induced motility of differentiated neurons. Cerebral Cortex. Oxford University Press. https://doi.org/10.1093/cercor/bht067 chicago: Chai, Xuejun, Gert Münzner, Shanting Zhao, Stefanie Tinnes, Janina Kowalski, Ute Häussler, Christina Young, Carola Haas, and Michael Frotscher. “Epilepsy-Induced Motility of Differentiated Neurons.” Cerebral Cortex. Oxford University Press, 2014. https://doi.org/10.1093/cercor/bht067. ieee: X. Chai et al., “Epilepsy-induced motility of differentiated neurons,” Cerebral Cortex, vol. 24, no. 8. Oxford University Press, pp. 2130–2140, 2014. ista: Chai X, Münzner G, Zhao S, Tinnes S, Kowalski J, Häussler U, Young C, Haas C, Frotscher M. 2014. Epilepsy-induced motility of differentiated neurons. Cerebral Cortex. 24(8), 2130–2140. mla: Chai, Xuejun, et al. “Epilepsy-Induced Motility of Differentiated Neurons.” Cerebral Cortex, vol. 24, no. 8, Oxford University Press, 2014, pp. 2130–40, doi:10.1093/cercor/bht067. short: X. Chai, G. Münzner, S. Zhao, S. Tinnes, J. Kowalski, U. Häussler, C. Young, C. Haas, M. Frotscher, Cerebral Cortex 24 (2014) 2130–2140. date_created: 2018-12-11T11:56:04Z date_published: 2014-08-01T00:00:00Z date_updated: 2021-01-12T06:55:43Z day: '01' department: - _id: PeJo doi: 10.1093/cercor/bht067 intvolume: ' 24' issue: '8' language: - iso: eng month: '08' oa_version: None page: 2130 - 2140 publication: Cerebral Cortex publication_status: published publisher: Oxford University Press publist_id: '4820' quality_controlled: '1' scopus_import: 1 status: public title: Epilepsy-induced motility of differentiated neurons type: journal_article user_id: 4435EBFC-F248-11E8-B48F-1D18A9856A87 volume: 24 year: '2014' ...