Synapses are highly specialized cell-cell junctions that mediate communication between neurons. These structures are composed of pre- and post-synaptic terminals and are the basis for the complex circuitry found in the brain. Most postsynaptic terminals of excitatory synapses take the form of dendritic spines, which are actin-rich protrusions that emanate from the dendrite shaft. Not surprisingly, the formation and plasticity of dendritic spines and synapses play a central role in cognitive function and abnormalities in these structures are associated with a number of neurological disorders. Despite the importance of spines and synapses in the central nervous system, the molecular mechanisms that regulate the formation of these structures are not well understood. A limitation toward identifying key molecules that regulate spine and synapse formation has been the great difficulty in observing synapses as they form. We are developing novel microfluidic devices that will allow us to dynamically observe forming synapses (Specific Aim I). Several innovations in the design of these devices will significantly enhance our ability to image the early steps of synapse formation with high spatial and temporal resolution.
In Specific Aim II, we will apply this technology to examining the spatiotemporal dynamics of actin during synaptic assembly. In addition, we will test our hypothesis that the activity of Rho family GTPases, which are key regulators of actin, is critical in the initial assembly and maturation of synapses. For these experiments, we will use cutting-edge microscopy technologies, including FRAP, photoactivation, and FRET to examine actin dynamics and regulation during synapse formation. The development of these microfluidic platforms will be of great interest and benefit to neurobiologist by providing a platform for identifying the key molecular signals that regulate the assembly of synapses.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21MH093903-02
Application #
8306755
Study Section
Neurotechnology Study Section (NT)
Program Officer
Asanuma, Chiiko
Project Start
2011-08-01
Project End
2014-07-31
Budget Start
2012-08-01
Budget End
2014-07-31
Support Year
2
Fiscal Year
2012
Total Cost
$233,737
Indirect Cost
$83,737
Name
Vanderbilt University Medical Center
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Brewer, Bryson M; Shi, Mingjian; Edd, Jon F et al. (2014) A microfluidic cell co-culture platform with a liquid fluorocarbon separator. Biomed Microdevices 16:311-23