The molecular mechanisms involved in synapse formation in the central nervous system are unclear. Although it is known that contact of the presynaptic axon with the postsynaptic dendrite induces pre-and post-synaptic differentiation of the synapse, the molecules involved in this process have not been identified. Studies of the neuromuscular junction have shown that presynaptic release of the proteoglycan agrin induces postsynaptic differentiation and clustering of the postsynaptic nicotinic acetylcholine receptor. To investigate the factors involved in the postsynaptic differentiation of excitatory synapses in the CNS we have recently reconstituted synapse formation between axons and non-neuronal cells expressing glutamate receptors and other synaptic components. Incubation of neurons with non-neuronal cells under these conditions promotes differentiation of the presynaptic nerve terminal and clustering of AMPA receptors at the point of contact between the axon and the transfected non-neuronal cell. Electrophysiological recordings of the non-neuronal cells remarkably show synaptic excitatory postsynaptic currents (EPSCs) and mEPSCs. Using this system we will characterize the requirements for postsynaptic clustering of AMPA receptors. Initially we will characterize the structural domains of the AMPA receptor subunits required for this clustering. Deletions of the intracellular C-terminal region of the subunits will be performed to investigate whether intracellular protein interactions are required. Deletions of extracellular domains of the subunits will be performed to see if direct interaction of the AMPA receptor subunits with proteins secreted from the axon is required for receptor clustering. Information from these studies will be used for isolation of the molecules that promote AMPA receptor clustering. These studies will help identify molecules involved in synapse formation and modulation during development and in the adult. Since many neurological and psychiatric diseases result from defects in synaptic transmission, understanding the basic mechanisms regulating synaptic function is critical for the development of therapeutic treatments for these disorders.

National Institute of Health (NIH)
National Institute of Mental Health (NIMH)
Specialized Center (P50)
Project #
Application #
Study Section
Special Emphasis Panel (ZMH1)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Johns Hopkins University
United States
Zip Code
Huang, Guo N (2012) T Cell Calcium Mobilization Study (Flow Cytometry). Bio Protoc 2:
Huang, Guo N (2012) Biotinylation of Cell Surface Proteins. Bio Protoc 2:
Zou, Jia; Zhou, Liang; Du, Xiao-Xia et al. (2011) Rheb1 is required for mTORC1 and myelination in postnatal brain development. Dev Cell 20:97-108
Lee, Kyu Pil; Yuan, Joseph P; Zeng, Weizhong et al. (2009) Molecular determinants of fast Ca2+-dependent inactivation and gating of the Orai channels. Proc Natl Acad Sci U S A 106:14687-92
Yuan, Joseph P; Kim, Min Seuk; Zeng, Weizhong et al. (2009) TRPC channels as STIM1-regulated SOCs. Channels (Austin) 3:221-5
Kim, Min Seuk; Zeng, Weizhong; Yuan, Joseph P et al. (2009) Native Store-operated Ca2+ Influx Requires the Channel Function of Orai1 and TRPC1. J Biol Chem 284:9733-41
Yuan, Joseph P; Zeng, Weizhong; Dorwart, Michael R et al. (2009) SOAR and the polybasic STIM1 domains gate and regulate Orai channels. Nat Cell Biol 11:337-43
Park, Sungjin; Park, Joo Min; Kim, Sangmok et al. (2008) Elongation factor 2 and fragile X mental retardation protein control the dynamic translation of Arc/Arg3.1 essential for mGluR-LTD. Neuron 59:70-83
Zeng, Weizhong; Yuan, Joseph P; Kim, Min Seuk et al. (2008) STIM1 gates TRPC channels, but not Orai1, by electrostatic interaction. Mol Cell 32:439-48
Shin, Jung Hoon; Kim, Yu Shin; Linden, David J (2008) Dendritic glutamate release produces autocrine activation of mGluR1 in cerebellar Purkinje cells. Proc Natl Acad Sci U S A 105:746-50

Showing the most recent 10 out of 28 publications