Fig. 11.

Schematic functioning of the spatial buffering during the slow oscillation (A) and SW seizures (B). A, During the depolarizing phase of the slow oscillation, small and local increases of extracellular K⁺ (circle) may occur in the proximity of the axon hillock. The neighboring glial cells take it up and redistribute it at sites where the [K⁺]_out has normal values. These locations may be close to a synapse, in which case the synaptic efficiency may be modulated, or close to a neuronal membrane so as to modify the excitability of that membrane. B, Important increases in the [K⁺]_out may not be buffered at short distances, in which case the taken up K⁺ may travel through the glial syncytium and is externalized at a location with lower [K⁺]_out values, where it would modulate the activity of nearby neurons.