Brain cell microenvironment effects on neuron excitability and basal metabolism.

In a model of neurons in a brain cell assembly, changes in volume of the extracellular space affect neuronal excitability and basal metabolism. A widely applicable coefficient of excitability with respect to a variation of the volume fraction has been determined. Calculations suggest that chloride increases membrane stability by indirectly promoting an acceleration of the metabolic pumping rate as a response to a diminished extracellular volume fraction. Volume fraction changes induced by cell swelling in a compact and highly tortuous microenvironment may play a role in epilepsy and, following brain damage, in cell death and recovery.