Figure 1. GABAergic astrocytes in AD. (A) GABA pathways in reactive astrocytes. Abbreviations: GAT1/3 GABA transporters 1 (SLC6A1) and 3 (SLC6A11); Best1 - bestrophin 1 anion channel 1; GABA-T - GABA transaminase; TCA - tricarboxylic acid (Krebs) cycle; MAO-B - Monoamine oxidase B; GAD67 - glutamate decarboxylase. (B) Reactive astrocytes in the vicinity of amyloid plaques in AD. Plaque (P) vicinity (pink shading) contains normal (green), silent (blue) and hyperactive (red) neurons (N), as well as hypertrophic astrocytes (A) and microglia (M) with enhanced Ca2+ signaling. Glutamate released, for example, from hyperactive neurons is taken up by astrocytes and metabolized to GABA. GABA release (i) inhibits neuronal activity and (ii) release of pro-inflammatory markers (e.g. TNF-α or IL-6) from astrocytes and microglia.