Prof. Dr. Ulrich Egert
Director of the Bernstein Center Freiburg &
Biomicrotechnology, Dept. of Microsystems Engineering
Faculty of Engineering
Georges-Köhler-Allee 102
79110 Freiburg i.Br.
Tel.: +49 (0)761 203 7524
ulrich.egert@imtek.uni-freiburg.de
We are part of the
MSc program in Neuroscience
at the University of Freiburg, Germany
Research Topics
- Mechanisms and functions underlying the spatial and temporal dynamics of activity in natural and artificial biological neuronal networks under physiological and pathophysiological conditions.
- The influence of mesoscale network structure on dynamics and robustness of neuronal network activity
- Mechanisms of epilepsy
- Control of network dynamics and interaction of stimulation with ongoing activity
- Neurotechnological hybrid systems
- Recording and analysis of spatial and temporal structure of electrical activity in neuronal networks in slices and cell cultures
We are interested in processing and activity dynamics in generic neuronal networks, the role of a network's mesoscale structure on its properties and new techniques for neuronal network electrophysiology. This we investigate by recording and analyzing the spatial and temporal structure of electrical activity in neuronal networks in slices, cell cultures of cortical neurons and in mice, based on spontaneous and electrically, optogenetically or pharmacologically stimulated activity as well as pharmacological modulation of network structure. We use intracellular whole-cell patch clamp recordings to identify single neuron properties and pairwise connectivity, in conjunction with network activity recorded simultaneously with microelectrode arrays (MEA) and calcium imaging. The main perspective here is the embedding of individual neurons into neuronal network dynamics and the heterogeneity of this across neurons.
As a pathological aspect of changes to the structure of neuronal networks, we investigate mechanisms underlying epilepsy. Specifically, we are interested in how the restructuring of the hippocampal network is reflected in interictal activity seemingly without salient signs of epileptiform activity and how to reduce the propensity to develop seizures by neurotechnological means.
Much of our work involves developing new tools to analyze and interpret our data, e.g. to relate whole cell patch clamp data to network dynamics, analyse spatial activity patterns as a function of network architecture, new measures for time resolved severity analysis of epileptic episodes or current susceptibility for seizures,
In terms of technical aspects we collaborate with several engineering groups to develop new devices for high-density extracellular recording in vitro and in vivo, autonomous control of closed-loop stimulation, also based on machine-learning approaches.
In previous projects we investigated the differentiation and structure of electrical activity in cardiac networks, developed applications for biological neuronal networks in drug screening, and addressed the use of biosensors to identify molecular markers associated with changing states of neuronal activity.
Techniques
- Single- and multiple-neuron recordings in slices, neuronal networks in cell cultures and in vivo
- Design and application of advanced data analysis techniques for electrophysiological data
- Cell culture techniques
- Neurotechnology
- Optogenetic analysis
- Calcium imaging
- Microelectrode array recoding in vivo and in vitro
Academic Background
- 2005: Habilitation at the Faculty of Biology, Univ. Freiburg
- 1995: Dr. rer. nat. (PhD) in Biology, Thesis: Development of thin-film microelectrode arrays and their application in neurophysiology.
- 1988 - 1995: PhD Studies, Eberhard-Karls University, Tübingen and Natural and Medical Sciences Institute, Reutlingen
- 1987: Diploma in Biology; Thesis on the effects of anesthetics on cortical visual plasticity and memory consolidation in kittens.
- 1983 - 1987: Graduate studies in biology, Eberhard-Karls University, Tübingen, Germany
- 1982 - 1983: Graduate studies in zoology, Duke University, Durham, NC, (USA)
- 1980 - 1982: Eberhard-Karls University Tübingen, Germany, Undergraduate studies in biology
Research Positions
- 2008 - present: Professor for Biomicrotechnology, Dept. of Microsystems Engineering, Faculty of Applied Sciences, Univ. Freiburg
- 2001 - 2007: Assistant Professor, Dept. Neurobiology and Biophysics, Faculty of Biology, Univ. Freiburg
- 1996 - 2007: Head of the Applied Neuroscience Laboratory, Dept. Neurobiology and Biophysics, Faculty of Biology, Univ. Freiburg
- 1988 - 1996: PhD-Student and Research Associate Position, Natural and Medical Sciences Institute, Reutlingen
Publications
2024
- Paschen E, Kleis P, Vieira DM, Heining K, Boehler C, Egert U, Häussler U, Haas CA (2023): On-demand low-frequency stimulation for seizure control: efficacy and behavioural implications. Brain 147(2), 505–520.
2023
- Okujeni S and Egert U (2023): Structural modularity tunes mesoscale criticality in biological neuronal networks. Journal of Neuroscience 43(14), 2515-2526.
DOI: https://doi.org/10.1523/JNEUROSCI.1420-22.2023
2021
- Vieira DM, Kilias A, Diehl M, Haas CA, Egert U (2021) Adaptive control of sinusoidal optogenetic stimulation. In: 2021 10th International IEEE/EMBS Conference on Neural Engineering (NER), pp 275–280. IEEE, DOI:10.1109/NER49283.2021.9441180.
- Kilias A, Lee Y-T, Froriep UP, Sielaff C, Moser D, Holzhammer T, Egert U, Fang W, Paul O, Ruther P (2021) Intracortical probe arrays with silicon backbone and microelectrodes on thin polyimide wings enable long-term stable recordings in vivo. J Neural Eng 18:066026, DOI:10.1088/1741-2552/ac39b7.
2020
- Kim CM, Egert U, Kumar A
Dynamics of multiple interacting excitatory and inhibitory populations with delays
2020 Phys Rev E, volume: 102, page: 022308 - Paschen E, Elgueta C, Heining K, Vieira DM, Kleis P, Orcinha C, Häussler U, Bartos M, Egert U, Janz P, Haas CA
Hippocampal low-frequency stimulation prevents seizure generation in a mouse model of mesial temporal lobe epilepsy.
2020 Elife, volume: 9, page: e54518 - Boehler C, Vieira DM, Egert U, Asplund M
NanoPt-A Nanostructured Electrode Coating for Neural Recording and Microstimulation.
2020 Acs Appl Mater Inter, Band: 12, Nummer: 13, Seiten: 14855 - 14865
2019
- Wülfing Jan M, Kumar Sreedhar S, Boedecker Joschka, Riedmiller Martin, Egert Ulrich
Adaptive Long-term Control of Biological Neural Networks with Deep Reinforcement Learning
2019 Neurocomputing, volume: 342, pages: 66 - 74 - Heining K, Kilias A, Janz, P, Häussler, U, Kumar, A, Haas, C A, Egert, U
Bursts with high and low load of epileptiform spikes show context-dependent correlations in epileptic mice
2019 eNeuro, volume: 6, page: /ENEURO.02
- Okujeni Samora, Egert Ulrich
Inhomogeneities in network structure and excitability govern initiation and propagation of spontaneous burst activity
2019 Frontiers in Neuroscience, volume: 13, page: 543 - Okujeni S, Egert U
Self-organization of modular network architecture by activity-dependent neuronal migration and outgrowth
2019 Elife, volume: 8, page: e47996
- Wülfing J, Kumar S S, Boedecker J, Riedmiller M, Egert U
Controlling Biological Neural Networks with Deep Reinforcement Learning
2018 i6doc.com publ., pages: 355 - 360 - Kilias A, Canales A, Froriep UP, Park S, Egert U, Anikeeva P
Optogenetic entrainment of neural oscillations with hybrid fiber probes.
2018 J Neural Eng, volume: 15, issue: 5, pages: 056006 - 056006 - Janz P, Hauser P, Heining K, Nestel S, Kirsch M, Egert U, Haas CA
Position- and Time-Dependent Arc Expression Links Neuronal Activity to Synaptic Plasticity During Epileptogenesis.
2018 Front Cell Neurosci, volume: 12, pages: 244 - 244 - Kilias A, Haussler U, Heining K, Froriep UP, Haas CA, Egert U
Theta frequency decreases throughout the hippocampal formation in a focal epilepsy model.
2018 Hippocampus, volume: 28, issue: 6, pages: 375 - 391
2017
- Okujeni S, Kandler S, Egert U
Mesoscale architecture shapes initiation and richness of spontaneous network activity.
2017 J Neurosci, volume: 37, issue: 14, pages: 3972 - 3987 - Janz P, Savanthrapadian S, Haussler U, Kilias A, Nestel S, Kretz O, Kirsch M, Bartos M, Egert U, Haas CA
Synaptic Remodeling of Entorhinal Input Contributes to an Aberrant Hippocampal Network in Temporal Lobe Epilepsy.
2017 Cereb Cortex, volume: 27, issue: 3, pages: 2348 - 2364
2016
- Kumar Sreedhar S, Wülfing Jan, Okujeni Samora, Boedecker Joschka, Riedmiller Martin, Egert Ulrich
A machine learning based approach to control network activity
Front Neurosci Conference Abstract: MEA Meeting 2016 | 10th International Meeting on Substrate-Integrated Electrode Arrays, 2016 - Heizmann S, Kilias A, Ruther P, Egert U, Asplund M
Active Control of Dye Release for Neuronal Tracing using PEDOT-PSS Coated Electrodes.
2016 Ieee T Neur Sys Reh - Kumar S S, Wülfing Jan, Okujeni Samora, Boedecker Joschka, Riedmiller Martin, Egert Ulrich
Autonomous control of network activity
Proceedings of AREADNE 2016, pages: 86 - 86, 2016 - Kumar SS, Wulfing J, Okujeni S, Boedecker J, Riedmiller M, Egert U
Autonomous optimization of targeted stimulation of neuronal networks.
2016 Plos Comput Biol, volume: 12, issue: 8, pages: e1005054 - e1005054 - Heizmann Stefanie, Holzhammer Tobias, Kilias Antje, Egert Ulrich, Ruther Patrick, Asplund Maria
Dye delivery from PEDOT electrodes in vivo - a new way to reconstruct recording sites
Frontiers in Neuroscience: 10th International Meeting on Substrate-Integrated Electrode Arrays, Reutlingen, Germany, 28 Jun - 1 Jul, 2016, volume: 10, 2016 - Haussler U, Rinas K, Kilias A, Egert U, Haas CA
Mossy fiber sprouting and pyramidal cell dispersion in the hippocampal CA2 region in a mouse model of temporal lobe epilepsy.
2016 Hippocampus, volume: 26, issue: 5, pages: 577 - 588 - Boehler C, Kleber C, Heizmann S, Ruther P, Hofmann U, Egert U, Ruehe J, Stieglitz T, Asplund M
Nanostructured and biofunctionalized coatings for microscale electrodes: bringing cutting edge materials science to microsystems engineered implants
Frontiers in Bioengineering and Biotechnology, volume: 4, pages: 3389 - 3389, 2016 - Safavieh E, Egert U
On the structural properties of burst origination and termination regions in simulated neural net-works
Bernstein Conference 2016, 2016 - Janz Philipp, Hauser P, Heining Katharina, Nestel Sigrun, Kretz Oliver, Kirsch Matthias, Egert Ulrich, Haas Carola A
Region-specific activity changes during epileptogenesis determine subcellular Arc mRNA localization and synaptic plasticity of dentate granule cells
FENS Conference Abstracts, 2016 - Orcinha C, Munzner G, Gerlach J, Kilias A, Follo M, Egert U, Haas CA
Seizure-Induced Motility of Differentiated Dentate Granule Cells Is Prevented by the Central Reelin Fragment.
2016 Front Cell Neurosci, volume: 10, pages: 183 - 183
2015
- Heizmann Stefanie, Kilias Antje, Okujeni Samora, Boehler Christian, Ruther Patrick, Egert Ulrich, Asplund Maria
Accurate neuronal tracing of microelectrodes based on PEDOT-dye coatings
2015 2015 7th International IEEE/EMBS Conference on Neural Engineering (NER), pages: 386 - 389 - Kumar, S S, Wülfing, J, Winterer, L, Okujeni, Samora, Boedecker, J, Wimmer, R, Riedmiller R, Becker B, Egert U
Autonomous control of network activity
2015 Bernstein Conference 2015, pages: T24 - T24 - Janz P, Häussler U, Kilias A, Kretz O, Kirsch M, Egert U, Haas CA
Entorhinal input contributes to an aberrant hippocampal circuitry in mesial temporal lobe epilepsy
2015 11 Göttingen Jahrestagung 2015 der Neurowissenschaftlichen Gesellschaft (NWG) - Safavieh E, Jarvis S, Rotter S, Egert U
Neuronal connectivity options along the edge of bounded neural networks – analysis of network structure and dynamics
Bernstein Conference 2015, 2015 - Kim, Christopher, Kilias, Antje, Sahasranamam, Ajith, Rotter, Stefan, Egert, Ulrich, Kumar, Arvind
Origin and control of dynamic instability in a computational model of epileptic network
2015 Bernstein Conference 2015 - Janz, Philipp, Savanthrapadian, Shakuntala, Häussler, Ute, Kilias, Antje, Nestel, Sigrun, Kretz, Oliver, Kirsch, Matthias, Bartos, Marlene, Egert, Ulrich, Haas, Carola A
Structural and functional plasticity of entorhinal input contributes to an epileptic hippocampal circuitry
2015 Society for Neuroscience Abstracts
2014
- Kumar S S, Wülfing J, Boedecker J, Wimmer R, Riedmiller R, Becker B, Egert U
Autonomous control of network activity
Proc of the 9th Int’l Meeting on Substrate-Integrated Microelectrode Arrays (MEA), 2014 - Kilias A, Froriep U P, Haeussler U, Kumar A, Haas C A, Egert U
Phase coupling of neuronal firing to hippocampal network rhythms is preserved under epileptic conditions
Epilepsia, volume: 55, pages: 41 - 42, 2014 - Asplund M, Boehler C, Heizmann S, Egert U, Hoffmann U, Stieglitz T
Polymer electrodes for drug release during stimulation
2014 Biomed Eng-biomed Te, volume: 59, pages: S1076 - S1076
2013
- Weihberger O, Okujeni S, Mikkonen JE, Egert U
Quantitative examination of stimulus-response relations in cortical networks in vitro.
2013 J Neurophysiol, volume: 109, issue: 7, pages: 1764 - 1774
2012
- Froriep UP, Kumar A, Cosandier-Rimélé D, Häussler U, Kilias A, Haas C, Egert U
Altered theta coupling between medial entorhinal cortex and dentate gyrus in temporal lobe epilepsy
2012 Epilepsia, volume: 53, issue: 11, pages: 1937 - 1947 - Levine-Small N, Guebeli R J, Goddard M, Yang A, Chuong A S, Chow B, Boyden E S, Weber W, Egert U
Astrocytes drive neural network synchrony
2012 MEA Meeting 2012, pages: 30 - 30
2011
- Froriep UP, Kilias A, Kumar A, Haas CA, Egert U
Inverted theta-gamma coupling in a model of temporal lobe epilepsy
2011 Bernstein Conference 2011: Computational Neuroscience & Neurotechnology Bernstein Conference & Neurex Annual Meeting Frontiers in Computational Neuroscience
2010
- Jarvis S, Rotter S, Egert U
Extending stability through hierarchical clusters in echo state networks.
2010 Front Neuroinform, volume: 4 - Gürel T, Rotter S, Egert U
Functional identification of biological neural networks using reservoir adaptation for point processes.
2010 J Comput Neurosci, volume: 29, issue: 1-2, pages: 279 - 299 - Gürel T, Rotter S, Okujeni S, Weihberger O, Egert U
Modeling persistent temporal patterns in dissociated cortical cultures using reservoir computing
Proceedings of the Nineteenth Annual Computational Neuroscience Meeting, 2010 - Kandler S, Okujeni S, Reinartz S, Egert U
Networks in dissociated culture follow native cortical development
2010 Proceedings of the 7th International Meeting on Substrate-Integrated Electrode Arrays - Tetzlaff C, Okujeni S, Egert U, Worgotter F, Butz M
Self-organized criticality in developing neuronal networks.
2010 Plos Comput Biol, volume: 6, issue: 12, pages: e1001013 - e1001013
2009
- Frey U, Egert U, Jackel D, Sedivy J, Ballini M, Livi P, Faraci F, Heer F, Hafizovic S, Roscic B, Hierlemann A
Depth recording capabilities of planar high-density microelectrode arrays
2009 Proc of the 4th International IEEE EMBS Conference on Neural Engineering, pages: 207 - 210 - Frey U, Egert U, Heer F, Hafizovic S, Hierlemann A
Microelectronic system for high-resolution mapping of extracellular electric fields applied to brain slices.
2009 Biosens Bioelectron, volume: 24, issue: 7, pages: 2191 - 2198 - Gürel T, Rotter S, Egert U
Reservoir computing methods for functional identification of biological networks
18th Annual Computational Neuroscience Meeting CNS 2009, 2009 - Frey U, Egert U, Heer F, Hafizovic S, Hierlemann A
Subcellular-resolution recording of electrical activity using a CMOS microelectrode system
2009 Proc of the 15th International Conference on Solid-State Sensors, Actuators & Microsystems, Transducers, pages: 1674 - 1677
2008
- Meier R, Egert U, Aertsen A, Nawrot MP
FIND-a unified framework for neural data analysis.
2008 Neural Networks, volume: 21, issue: 8, pages: 1085 - 1093 - Okujeni S, Kandler S, Egert U
Homeostatic regulation of activity in cortical networks
BIOPRO Baden-Württemberg GmbH, pages: 74 - 75, 2008
2007
- Frey U, Sanchez-Bustamante CD, Ugniwenko T, Heer F, Sedivy J, Hafizovic S, Roscic B, Fussenegger M, Blau A, Egert U, Hierlemann A
Cell recordings with a CMOS high-density microelectrode array.
2007 Conf Proc IEEE Eng Med Biol Soc, volume: 2007, pages: 167 - 170 - Reppel M, Igelmund P, Egert U, Juchelka F, Hescheler J, Drobinskaya I
Effect of cardioactive drugs on action potential generation and propagation in embryonic stem cell-derived cardiomyocytes.
2007 Cell Physiol Biochem, volume: 19, issue: 5-6, pages: 213 - 224 - Gürel T, Egert U, Kandler S, de Raedt L, Rotter S
Predicting spike activity in neuronal cultures
BMC Neuroscience, volume: 8, issue: (Suppl. 2), pages: 2942 - 2947, 2007 - Meier R, Haussler U, Aertsen A, Deransart C, Depaulis A, Egert U
Short-term changes in bilateral hippocampal coherence precede epileptiform events.
2007 Neuroimage, volume: 38, issue: 1, pages: 138 - 149 - Meier R, Haussler U, Aertsen A, Depaulis A, Egert U
Short-term changes in interhippocampal coherence precede epileptiform activity in mice with induced epilepsy
2007 Epilepsia, volume: 48 (C) , supplement: 3, pages: 32 - 32
2006
- Egert U, Banach K, Meyer T
Analysis of cardiac myocyte activity dynamics with microelectrode arrays
In: Advances in network electrophysiology using multi electrode arrays
2006, Springer Vlg., Taketani,M.; Baudry,M., pages: 274 - 290, Taketani,M.; Baudry,M., ISBN: 0387258574 - Kandler S, Egert U
Functional classification of neuroleptics based on population response profiles
2006 BIOPRO Baden-Württemberg GmbH, pages: 126 - 127 - Egert U
Networks on chips - Monitoring the spatial and temporal dynamics of electrical activity in functional networks in brain slices and cardiac tissue
In: BioMEMS
2006, Springer Vlg., Urban G, pages: 309 - 350, Urban G, ISBN: 0-387-28731-0
2005
- Egert U, Meyer T
Heart on a chip - Extracellular multielectrode recordings from cardiac myocytes in vitro
In: Practical Methods in Cardiovascular Research
2005, Springer Vlg., Dhein,S.; Mohr,F.-W.; Delmar,M., pages: 432 - 453, Dhein,S.; Mohr,F.-W.; Delmar,M., ISBN: 3540407634 - Stett A, Rudorf R, Egert U, Boven K-H, Gottschlich N, Nisch W
Perforated polyimide microelectrode arrays for single-cell and tissue recording
2005 VDE Verlag, pages: 427 - 430
2004
- Hescheler J, Halbach M, Egert U, Lu ZJ, Bohlen H, Fleischmann BK, Reppel M
Determination of electrical properties of ES cell-derived cardiomyocytes using MEAs.
2004 J Electrocardiol, volume: 37, supplement: 1, pages: 110 - 116
2003
- Stett A, Egert U, Guenther E, Hofmann F, Meyer T, Nisch W, Haemmerle H
Biological application of microelectrode arrays in drug discovery and basic research.
2003 Anal Bioanal Chem, volume: 377, issue: 3, pages: 486 - 495 - Halbach M, Egert U, Hescheler J, Banach K
Estimation of action potential changes from field potential recordings in multicellular mouse cardiac myocyte cultures.
2003 Cell Physiol Biochem, volume: 13, issue: 5, pages: 271 - 284
2002
- Egert U, Hämmerle H
Application of the microelectrode-array (MEA) technology in pharmaceutical drug research
In: Sensoren im Fokus neuer Anwendungen
2002, w.e.b. Universitätsverlag, Baselt,J.P.; Gerlach,G., pages: 51 - 54, Baselt,J.P.; Gerlach,G., - Egert U, Knott T, Schwarz C, Nawrot M, Brandt A, Rotter S, Diesmann M
MEA-Tools: an open source toolbox for the analysis of multi-electrode data with MATLAB.
2002 J Neurosci Meth, volume: 117, issue: 1, pages: 33 - 42 - Egert U, Heck D, Aertsen A
Two-dimensional monitoring of spiking networks in acute brain slices.
2002 Exp Brain Res, volume: 142, issue: 2, pages: 268 - 274
1998
- Egert U, Schlosshauer B, Fennrich S, Nisch W, Fejtl M, Knott T, Muller T, Hammerle H
A novel organotypic long-term culture of the rat hippocampus on substrate-integrated multielectrode arrays.
1998 Brain Res Protoc, volume: 2, issue: 4, pages: 229 - 242
1996
- Janders M, Egert U, Stelzle M, Nisch W
Novel thin film titanium nitride micro-electrodes with excellent charge transfer capability for cell stimulation and sensing applications.
1996 , pages: 48 - 49
1995 and earlier
- Egert U, Knott Th, Mohr A, Nisch W, Hämmerle H
An in vitro model system for studies of horizontal interaction in excised retina segments with a multielectrode-array
Thieme, Elsner N, Menzel R, page: 449, 1995
- Nisch W, Bock J, Egert U, Hammerle H, Mohr A
A thin film microelectrode array for monitoring extracellular neuronal activity in vitro.
1994 Biosensors and Bioelectronics, volume: 9, issue: 9-10, pages: 737 - 741 - Hämmerle H, Egert U, Mohr A, Nisch W
Extracellular recording in neuronal networks with substrate integrated microelectrode arrays.
1994 Biosens Bioelectron, volume: 9, issue: 9-10, pages: 691 - 696
- Schlosshauer B, Stier H, Egert U
Graded distribution of the neural 2A10 antigen in the developing chicken retina.
1993 Dev Brain Res, volume: 76, issue: 1, pages: 13 - 22
- Rauschecker JP, Tian B, Korte M, Egert U
Crossmodal changes in the somatosensory vibrissa/barrel system of visually deprived animals.
1992 P Natl Acad Sci Usa, volume: 89, issue: 11, pages: 5063 - 5067
- Rauschecker JP, Egert U, Kossel A
Effects of NMDA antagonists on developmental plasticity in kitten visual cortex.
1990 Int J Dev Neurosci, volume: 8, issue: 4, pages: 425 - 435