Molecular regulation of NMDA receptors in midbrain dopaminergic neurones. (360G-Wellcome-092611_Z_10_Z)

The proposed research will investigate the molecular regulation of NMDARs in DA neurones of the substantia nigra. Focussing on the substantia nigra pars compacta, where we have previously shown that the receptors are NR2B and NR2D subtypes, our key goals are to determine: (i) The relative importance of dynamin-dependent and dynamin-independent endocytosis and the role of MAGUK protein - NMDAR subunit interactions in NMDAR regulation at synaptic and extrasynaptic locations. (ii) The importanc e of NR2B and NR2D subunits in the intracellular regulation of synaptic and extra-synaptic NMDARs by kinases and phosphatases. (iii) The effects of NR2D subunit deletion on synaptic receptor density synaptic and on the biophysical properties of synaptic and extrasynaptic NMDAR. (iv) The importance of receptor trafficking and NR2D subunit-containing NMDARs in regulating phasic burst firing of DA neurones. Our approach to distinguish subunit-dependent and subunit-independent mechanisms invo lved in regulating synaptic and extrasynaptic receptors will incorporate high resolution patch-clamp recordings of NMDAR biophysical properties and application of appropriate inhibitors, activators and small interfering peptides to manipulate intracellular signalling molecules.