The photoreceptor cells of the retina carry out the essential task of translating light into electrical signals, which are then transmitted to retinal bipolar neurons for further analysis before being communicated to the rest of the visual system. All visual information must pass through this obligatory pathway, which involves two synaptic relays, one from photoreceptors to bipolar cells, and another from bipolar cells to third-order neurons of the inner retina. Both of these through-conducting synapses are specialized for continuous release of chemical neurotransmitter, which is required for the proper transmission of visual information. Despite their crucial role in vision, these unique photoreceptor and bipolar-cell synapses remain poorly understood, and it is not yet known how they are able to support high rates of neurotransmitter release for prolonged periods, while other synapses in the brain fatigue rapidly during sustained stimulation. This project will use a combination of cellular electrophysiology and high-resolution fluorescence imaging to provide the first complete picture of the synaptic vesicle cycle at the special synapses of retinal bipolar neurons and photoreceptor cells. The vesicle cycle can be broken down into several components: rapid fusion of synaptic vesicles to initiate transmitter release, resupply of releasable vesicles to support continued release, movement of vesicles to and from reserve and releasable pools, compensatory endocytosis to retrieve fused vesicles, and regeneration of new releasable vesicles after endocytosis.
The specific aims of the project exploit the ability to tag synaptic vesicles and synaptic active zones with distinct fluorescent labels to observe directly the vesicle movements that underlie all these components of the vesicle cycle. Then, genetic manipulations and selective protein interference will be used to unravel the molecular machinery that gives retinal synapses the unique ability to release neurotransmitter continuously and allows them to perform their central role in transmitting visual signals. The results will provide essential new information about how the visual signals arising in the photoreceptor cells are ultimately transmitted to the rest of the brain.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY003821-31
Application #
8197278
Study Section
Biology and Diseases of the Posterior Eye Study Section (BDPE)
Program Officer
Greenwell, Thomas
Project Start
1981-08-01
Project End
2012-11-30
Budget Start
2011-12-01
Budget End
2012-11-30
Support Year
31
Fiscal Year
2012
Total Cost
$366,477
Indirect Cost
$128,877
Name
State University New York Stony Brook
Department
Other Basic Sciences
Type
Schools of Arts and Sciences
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
Vaithianathan, Thirumalini; Matthews, Gary (2014) Visualizing synaptic vesicle turnover and pool refilling driven by calcium nanodomains at presynaptic active zones of ribbon synapses. Proc Natl Acad Sci U S A 111:8655-60
Vaithianathan, Thirumalini; Zanazzi, George; Henry, Diane et al. (2013) Stabilization of spontaneous neurotransmitter release at ribbon synapses by ribbon-specific subtypes of complexin. J Neurosci 33:8216-26
Vaithianathan, Thirumalini; Akmentin, Wendy; Henry, Diane et al. (2013) The ribbon-associated protein C-terminal-binding protein 1 is not essential for the structure and function of retinal ribbon synapses. Mol Vis 19:917-26
Vega, Ana V; Avila, Guillermo; Matthews, Gary (2013) Interaction between the transcriptional corepressor Sin3B and voltage-gated sodium channels modulates functional channel expression. Sci Rep 3:2809
Snellman, Josefin; Mehta, Bhupesh; Babai, Norbert et al. (2011) Acute destruction of the synaptic ribbon reveals a role for the ribbon in vesicle priming. Nat Neurosci 14:1135-41
Hunanyan, Arsen S; Alessi, Valentina; Patel, Samik et al. (2011) Alterations of action potentials and the localization of Nav1.6 sodium channels in spared axons after hemisection injury of the spinal cord in adult rats. J Neurophysiol 105:1033-44
Matthews, Gary; Fuchs, Paul (2010) The diverse roles of ribbon synapses in sensory neurotransmission. Nat Rev Neurosci 11:812-22
Zanazzi, George; Matthews, Gary (2010) Enrichment and differential targeting of complexins 3 and 4 in ribbon-containing sensory neurons during zebrafish development. Neural Dev 5:24
Logiudice, L; Sterling, P; Matthews, G (2009) Vesicle recycling at ribbon synapses in the finely branched axon terminals of mouse retinal bipolar neurons. Neuroscience 164:1546-56
Zanazzi, George; Matthews, Gary (2009) The molecular architecture of ribbon presynaptic terminals. Mol Neurobiol 39:130-48

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