Brain ischemic injury represents one of the greatest medical challenges for the aging population in
developed countries, yet despite strong efforts, possibilities to treat ischemic injury still remain poor. Stroke, the
most common type of brain ischemic injury in humans, is caused by brain artery occlusion, and represents a focal
form of ischemia, which leads to neuronal loss in the ischemic core, and glial scar formation in the penumbral
region around the core. Such glial scar mainly comprises reactive astrocytes, reactive NG2 glia and activated
microglia. Reactive astrocytes display distinct features when compared to healthy astroglia, including changes in
their morphology, metabolism, gene expression profiles, production of extracellular matrix proteins or proliferation
rate. Similarly to astrocytes in the healthy nervous tissue, reactive astrocytes surrounding the glial scar
strongly influence the activity of surviving neurons around the ischemic lesion. Bringing insight into pathophysiological
functions of reactive astrocytes within the glial scar might thus open new possibilities for stroke treatment.
Here, we summarize the properties of reactive astrocytes, with emphasis on the expression and function of
ion channels, transporters and neurotransmitter receptors; all of which possess the ability to change the functional
state of astrocytes, such as the membrane equilibrium potentials for different ions. This may have major effects
on the functioning of surviving neurons, consequently leading to changes in neuronal excitability and progression
of secondary pathologies, such as epilepsy. Moreover, we provide possible clues for therapy, based on functional
modulation of astrocytic ion transporting mechanisms.