Kivonat:
Our present review is focusing on the uniqueness of balanced
astroglial signaling. The balance of excitatory and inhibitory
signaling within the CNS is mainly determined by sharp synaptic
transients of excitatory glutamate (Glu) and inhibitory gamma-
aminobutyrate (GABA) acting on the sub-second timescale.
Astroglia is involved in excitatory chemical transmission by
taking up i) Glu through neurotransmitter-sodium transporters,
ii) K+ released due to presynaptic action potential generation,
and iii) water keeping osmotic pressure. Glu uptake-coupled Na+
influx may either ignite long-range astroglial Ca2+ transients
or locally counteract over-excitation via astroglial GABA
release and increased tonic inhibition. Imbalance of excitatory
and inhibitory drives is associated with a number of disease
conditions, including prevalent traumatic and ischaemic
injuries or the emergence of epilepsy. Therefore, when
addressing the potential of early therapeutic intervention,
astroglial signaling functions combating progress of Glu
excitotoxicity is of critical importance. We suggest, that
excitotoxicity is linked primarily to over-excitation induced by
the impairment of astroglial Glu uptake and/or GABA release.
Within this framework, we discuss the acute alterations of Glu-
cycling and metabolism and conjecture the therapeutic promise of
regulation. We also confer the role played by key carrier
proteins and enzymes as well as their interplay at the
molecular, cellular, and organ levels. Moreover, based on our
former studies, we offer potential prospect on the emerging
theme of astroglial succinate sensing in course of Glu
excitotoxicity.