title: NMDA Receptors in Glial Cells: Pending Questions.
abstract: Glutamate receptors of the N-methyl-D-aspartate (NMDA) type are involved in many cognitive processes, including behavior, learning and synaptic plasticity. For a long time NMDA receptors were thought to be the privileged domain of neurons; however, discoveries of the last 25 years have demonstrated their active role in glial cells as well. Despite the large number of studies in the field, there are many unresolved questions connected with NMDA receptors in glia that are still a matter of debate. The main objective of this review is to shed light on these controversies by summarizing results from all relevant works concerning astrocytes, oligodendrocytes and polydendrocytes (also known as NG2 glial cells) in experimental animals, further extended by studies performed on human glia. The results are divided according to the study approach to enable a better comparison of how findings obtained at the mRNA level correspond with protein expression or functionality. Furthermore, special attention is focused on the NMDA receptor subunits present in the particular glial cell types, which give them special characteristics different from those of neurons - for example, the absence of Mg(2+) block and decreased Ca(2+) permeability. Since glial cells are implicated in important physiological and pathophysiological roles in the central nervous system (CNS), the last part of this review provides an overview of glial NMDA receptors with respect to ischemic brain injury.
authors.affiliation: Department of Cellular Neurophysiology, Institute of Experimental Medicine AS CR, Prague, Czech Republic and Second Medical Faculty, Charles University, Prague, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Dzamba
authors.forename: Pavel
authors.initials: P
authors.lastname: Honsa
authors.forename: Miroslava
authors.initials: M
authors.lastname: Anderova
keywords: Astrocytes; NG2 glia; NMDA receptors; ischemia; oligodendrocyte progenitors; oligodendrocytes; polydendrocytes.