From spiking neurons to brain waves

General info

Date from - to

15 Oct 2008 - 31 Mar 2013

Abstract

In this research project we will test three hypotheses. The first hypothesis is related to the functional role of neuronal oscillations in the gamma-frequency range (30-100 Hz) and postulates that neuronal groups coherently oscillating in the gamma-range can interact effectively, because their communication windows for input and for output are open at the same times. Stable synchronous firing between two groups of neurons will occur if oscillatory activity of group A arrives at the target neurons in B precisely at the phase when excitability of neurons in B is high. We postulate that the explanation has to be sought in the nonlinear dynamical properties of neurons. The second hypothesis postulates a special role of inhibitory interneurons in the generation of a robust gamma-rhythm. If neuronal activity in the gamma-frequency range is most effective in activating other neurons, the question comes up which mechanism prohibits gamma-activity to activate an ever-increasing number of neurons, like in epileptic seizures. Many focal epileptic seizures start with an increase of gamma activity with abnormal spreading. We postulate (hypothesis 3) that a regulating mechanisms is affected in patients.

These hypotheses will be tested using mathematical analyses and extensive computer simulations at the level of interactions between single neurons and populations of neurons. The results of these approaches will be compared to data in large data-bases obtained by subdural recordings in patients with normal task-related gamma activity and with epileptic seizures. The results of this project will allow pro-active recognition of starting epileptic activity.

Coordinator: Prof. dr. C.C.A.M. Gielen, Radboud University Nijmegen, Faculty of Scinece, Biofysics