Mentor: Dr. Karen Greif
A synapse is the structure through which neurons communicate by the release of neurotransmitters. Before this can occur, a developing neuron must extend an axon, synthesize synaptic proteins, and transport them to synaptic terminals. Many proteins that play a role in synaptic function have been identified. Evidence suggests that some synaptic proteins may contribute to neurite outgrowth as well. We have chosen two proteins to study, synaptotagmin and syntaxin because they are necessary for synaptic function. We hope to characterize the time course and the transport of the two proteins during synaptogenesis. The model chosen for this experiment is the sympathetic innervation of the pineal gland by the Superior Cervical Ganglion(SCG). This pathway is visualized in vivo using recombinant adenoviruses to transfect neurons with the gene for a synaptotagmin-YFP fusion protein in the SCGs of neonatal rats. Syntaxin will be visualized using immunocytochemistry. The distribution of both proteins will be determined using a confocal microscope.
In a second experiment, we will observe the transport of synaptic proteins to the growth cones in vitro. This experiment, examines whether or not the proteins are transported simultaneously. Both native synaptotagmin and native syntaxin will be labeled in order to follow their transport and distribution in neurites. Both experiments may provide evidence as to why both essential proteins begin to appear in synapses much later than other synaptic proteins. The time course and transport of other synaptic proteins involved neurotransmission will also be examined.
Supported by NIH AREA grant #1R15NS40303.