BRAIN-CELL MICROENVIRONMENT EFFECTS ON NEURON EXCITABILITY AND BASAL-METABOLISM

IN a model of neurons in a brain cell assembly, changes in volume of t he extracellular space affect neuronal excitability and basal metaboli sm. A widely applicable coefficient of excitability with respect to a variation of the volume fraction has been determined. Calculations sug gest that chloride increases membrane stability by indirectly promotin g an acceleration of the metabolic pumping rate as a response to a dim inished extracellular volume fraction. Volume fraction changes induced by cell swelling in a compact and highly tortuous micro-environment m ay play a role in epilepsy and, following brain damage, in cell death and recovery.