The nature of early astroglial protection-Fast activation and signaling

•Major processes and players of excitation-inhibition balance via Glu homeostasis are highlighted.•Discussion of a novel, astroglial “sensor” of oxidative hypometabolism, stress and neuroinflammation is submitted.•Astrocytes are placed in the centre of Glu metabolism-reliant ammonia homeostasis.•Prevalent and invasive traumatic and ischaemic brain injuries are explored to validate the potential of the “gliocentric” concept of early therapeutic intervention.•The idea of excitation-dependent pulsing of “nanocapillars” taking shape by the synapse and perisynaptic astrocytic processes is promoted.