Transporters may also shape the activation of receptors on a more rapid time scale during synaptic transmission. EAAT1 and EAAT2 are expressed in glial cells, primarily astrocytes and Bergmann glia. The critical role of these glial transporters has been shown by the abnormal neuronal signaling and profound behavioral consequences observed when their activity is reduced. We study the properties of these glutamate transporters in expression systems as well as in acute tissue such as the hippocampus and cerebellum. Through these studies we hope to determine the fate of glutamate after it is released- how far it diffuses, the types and locations of the receptors it activates, and the role of transporters in shaping its spatial and temporal profile in the extracellular space.
Glial cells perform critical functions in the nervous system.
They provide the energy necessary to sustain neural activity, they sequester the ions and neurotransmitters released during synaptic transmission, and they form myelin sheets around axons allowing the rapid transmission of action potentials over long distances. Despite the interdependence of neurons and glia, little is known about the pathways used for communication between these two cell types. A related area of research in our lab involves the study of these pathways and their roles in development and synaptic physiology. As glutamate receptor signaling may regulate oligodendrocyte development and thus myelination, these studies may lead to new approaches for stimulating re-myelination after injury or disease. Synaptic activation of glutamate transporters in hippocampal astrocytes.