Role of astrocytes in epilepsy.
Astrocytes express ion channels, transmitter receptors, and transporters and, thus, are endowed with the machinery to sense and respond to neuronal activity. Recent studies have implicated that astrocytes play important roles in physiology, but these cells also emerge as crucial actors in epilepsy. Astrocytes are abundantly coupled through gap junctions allowing them to redistribute elevated K(+) and transmitter concentrations from sites of enhanced neuronal activity. Investigation of specimens from patients with pharmacoresistant temporal lobe epilepsy and epilepsy models revealed alterations in expression, localization, and function of astroglial K(+) and water channels. In addition, malfunction of glutamate transporters and the astrocytic glutamate-converting enzyme, glutamine synthetase, has been observed in epileptic tissue. These findings suggest that dysfunctional astrocytes are crucial players in epilepsy and should be considered as promising targets for new therapeutic strategies.
Departments of Pediatrics and Neuroscience, Perelman School of Medicine, University of Pennsylvania and the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104-4318.
Douglas A
DA
Coulter
Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53105 Bonn, Germany.
Christian
C
Steinhäuser
D000818:Animals; D051401:Aquaporin 4 / Q000235:genetics*; D001253:Astrocytes / Q000502:physiology*; D004833:Epilepsy, Temporal Lobe / Q000235:genetics / Q000503:physiopathology*; D017629:Gap Junctions / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism*; D006706:Homeostasis; D006801:Humans; D015221:Potassium Channels / Q000378:metabolism*; D009435:Synaptic Transmission
C496030:AQP4 protein, human; D051401:Aquaporin 4; D015221:Potassium Channels; D018698:Glutamic Acid