4 YEAR PhD IN NEUROSCIENCE
Department of Neuroscience, Physiology & Pharmacology
Molecular pharmacology of GABA and glycine receptor-ion channels
We study the structure-function relationships of GABA-A, GABA-B and glycine receptors and how these receptors are regulated, at synaptic and extrasynaptic sites, by endogenous agents in the CNS. We have concentrated on understanding how ions, e.g., zinc and protons as well as redox agents, and the process of phosphorylation by protein kinases, can affect the physiological function of, principally, GABA-A receptors. The methods we employ are mostly electrophysiological coupled with molecular biology and fluorophore imaging in fixed tissue and in live tissues in real time. Our electrophysiological techniques operate at both whole-cell and single ion channel recording levels, utilising recombinant receptors expressed in cell lines or native neuronal receptors in dissociated cultures. We also include , brain slice cultures or acutely prepared brain slices for the analyses of inhibitory synaptic currents. One of our goals is to use mutant GABA-A receptors, deposited at synaptic sites, to better understand the function of inhibitory synaptic receptors and their associated intracellular and extracellular regulatory domains. Mutant cDNAs are incorporated into live neurones using gene-gun technology, direct microinjection and lipofection techniques. Our studies are investigating how GABA-A receptors control neuronal excitability in addition to searching for novel drug targets.
Regulation of synaptic GABA-A receptors and their selective targeting to synaptic sites studied using a combination of electrophysiological, molecular and imaging techniques.
Using structural homology strategies in the search for ligand binding sites on GABA-A receptor-ion channels
McDonald, B.J., Amato, A., Connolly, C.N., Benke, D., Moss, S.J. & Smart, T.G. (1998)
Adjacent phosphorylation sites on the GABA-A receptor beta subunits determine regulation by cAMP-dependent protein kinase.
Nature Neuroscience 1, 23-28.
Wooltorton, J.R.A., McDonald, B.J., Moss, S.J. & Smart, T.G. (1997)
Identification of a zinc binding site on the murine GABA-A receptor complex: dependence on the second transmembrane domain of beta subunits.
J. Physiol. 505.3, 633-640.
Moss, S.J., Gorrie, G. & Smart, T.J. (1995)
Modulation of GABA-A receptor function by tyrosine phosphorylation.
Nature 377, 344-348.
Xie,X. & Smart,T.G. (1991)
A physiological role for endogenous zinc in rat hippocampal synaptic neurotransmission.
Nature 349, 521-524.