Year of Award

2014

Document Type

Dissertation

Degree Type

Doctor of Philosophy (PhD)

Degree Name

Neuroscience

Department or School/College

Department of Biomedical and Pharmaceutical Sciences

Committee Chair

Michael P. Kavanaugh

Commitee Members

Richard J. Bridges, J. Joshua Lawrence, Nicholas R. Natale, Sarah J. Certel, Leonid V. Kalachev

Abstract

Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system. An accurate spatial and temporal glutamate concentration profile during signaling is crucial for reliable neural computation. In these studies, we investigated the roles of glutamate transporters in controlling both ambient glutamate levels and dynamic glutamate concentrations profiles during synaptic transmission. Using the Xenopus oocyte expression system, we demonstrated that glutamate transporters act as an effective sink and are capable of maintaining >200 fold glutamate concentration gradient between the bath and cell surface when expressed at levels corresponding to physiological transporter densities in the CNS. We also characterized the specificity and actions of a new arylasparate glutamate transport inhibitor at the Shaffer collateral-CA1 pyramidal cell synapse in hippocampus, and demonstrated that glial glutamate transporters tightly control synaptically released glutamate and further, through cooperation with voltage-dependent Mg2+ block, they influence the magnitude and frequency-dependence of postsynaptic NMDA receptor signaling.

Share

COinS
 

© Copyright 2014 Weinan Sun