Figure 2. The activity change of glutamine synthetase (GS) in reactive astrocytes contributes to seizure development.

Figure 2The activity change of glutamine synthetase (GS) in reactive astrocytes contributes to seizure development

Glutamate (Glu) released at the excitatory synapse is converted into glutamine (Gln) through activity of GS in astrocytes. Glutamine is used as a precursor for synthesis of GABA in GABAergic neurons. The loss of GS in reactive astrocytes leads to a decrease in Gln and GABA levels in GABAergic terminals. Consequently, presynaptic GABAergic inhibition is reduced, increasing presynaptic release of Glu. In turn, Glu enhances the excitability of postsynaptic neurons, leading to a reduction in the seizure threshold.

From: Astrocytes and Epilepsy

Cover of Jasper's Basic Mechanisms of the Epilepsies
Jasper's Basic Mechanisms of the Epilepsies [Internet]. 4th edition.
Noebels JL, Avoli M, Rogawski MA, et al., editors.
Copyright © 2012, Michael A Rogawski, Antonio V Delgado-Escueta, Jeffrey L Noebels, Massimo Avoli and Richard W Olsen.

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