Two models of the neocortex are developed to study normal and pathologic neuronal activity. One model contains a detailed description of a neocortical microcolumn represented by 656 neurons, including superficial and deep pyramidal cells, four types of inhibitory neurons, and realistic synaptic contacts. Simulations show that neurons of a given type exhibit similar, synchronized behavior in this detailed model. This observation is captured by a population model that describes the activity of large neuronal populations with two differential equations with two delays. Both models appear to have similar sensitivity to variations of total network excitation. Analysis of the population model reveals the presence of multistability, which was also observed in various simulations of the detailed model.
From the *Department of Applied Mathematics and †MIRA-Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands; ‡Department of Pediatrics, The University of Chicago, Chicago, Illinois, U.S.A.; and §Department of Clinical Neurophysiology, Medical Spectrum Twente, Enschede, The Netherlands.
Supported by The Netherlands Organization of Scientific Research (NWO) grant 635.100.019: “From Spiking Neurons to Brain Waves” and Dr. Ralph and Marian Falk Medical Research Trust.
Presented at Tools for Epilepsy Research: Tutorials and Updates, Chicago, IL, August 6–8, 2009.
Address correspondence and reprint requests to Sid Visser, EWI-AAMP, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands; e-mail: firstname.lastname@example.org.