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DY: Fachverband Dynamik und Statistische Physik

DY 9: Focus Session: Dynamical Patterns in Neural Systems: From Brain Function to Dysfunction (joint session DY/ BP)

DY 9.1: Hauptvortrag

Dienstag, 1. April 2014, 09:30–10:00, HÜL 186

From epilepsy to migraine to stroke: A unifying framework. — •Markus A Dahlem — Department of Physics, Humboldt-Universität zu Berlin

We seek to understand in terms of quantitative mathematical models the dynamics of ion imbalances in three pathological conditions: epileptiform activity during seizures, cortical spreading depression in migraine, and anoxic depolarizations after stroke or traumatic brain injury. A family history of epilepsy increases the chances of having severe migraines and certain patients with migraine are at greater risk for stroke. The multiplicity of potential links include common genetic risk factors and indirect links like common triggers outside the brain. In the present approach, however, we will focus on basic electrophysiological mechanisms of neural excitability and the transitions between different activity forms related to ion imbalances in the brain. The change of both membrane potential and—due to reduced ion gradients—Nernst potentials together cause in varying degrees a release of Gibbs free energy, that is, the thermodynamic potential that measures the energy available to the neurons for normal functioning. We hence describe the three states related to epilepsy, migraine, and stroke in terms of their free energy starvation and stress. The mathematical description of such phenomena requires a broader thermodynamical perspective, as it goes beyond the original Hodgkin-Huxley description based on equivalent electrical circuits in membrane physiology.