This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. ULTRASTRUCTURAL BASIS FOR SYNAPTIC VESICLE RECYCLING IN THE CALYX OF HELD The calyx of Held and other large nerve terminals of the auditory brainstem are key elements of sound localization circuitry. Our goal is to reveal structural transformations and cellular communication that characterize contact of the calycigenic growth cone with its target and the early stages of synapse assembly and stabilization at large nerve terminals in the auditory brainstem. Our central hypothesis is that competition among calycigenic inputs precedes expansion of the terminal over the cell body to form a calyx. This hypothesis is based on work from our laboratory that reveals rapid formation of the calyx in mice between postnatal days (P)2 and P4. The calyx contains hundreds to greater than two thousand active zones, depending upon the species, many of which are located nearby specialized organelle complexes termed mitochondrion-associated adherens complexes (MACs). MAC structure had been described previously using standard transmission electron microscopy (sTEM), which revealed filaments tethering the mitochondrion to a punctum adherens that links the pre- and postsynaptic membranes. Confocal fluorescence imaging and electron tomography are being employed to study medial nucleus of the trapezoid body (MNTB) cell innervation during P0?P4. This time period precedes and overlaps the formation of immature, cup-shaped calyces that envelop the MNTB cell body. These experiments will pinpoint time periods during which mono-innervation is established between pre- and postsynaptic partners and highlight structural and functional differences that may predict winning and losing inputs. In addition, we will describe structural features of mature calyces that support high-rate neurotransmission that is characteristic of this terminal. Because of the size of the calyx-MNTB contact and the desired high resolution of the reconstructions, serial volumetric imaging of domains of cells will be required. This project will require high-resolution, wide-field, large-area digital recording of images for electron tomography.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR004050-23
Application #
8361902
Study Section
Special Emphasis Panel (ZRG1-BST-R (40))
Project Start
2011-04-01
Project End
2012-03-31
Budget Start
2011-04-01
Budget End
2012-03-31
Support Year
23
Fiscal Year
2011
Total Cost
$37,024
Indirect Cost
Name
University of California San Diego
Department
Neurosciences
Type
Schools of Medicine
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Funakoshi, Shunsuke; Miki, Kenji; Takaki, Tadashi et al. (2016) Enhanced engraftment, proliferation, and therapeutic potential in heart using optimized human iPSC-derived cardiomyocytes. Sci Rep 6:19111
Rubio-Marrero, Eva N; Vincelli, Gabriele; Jeffries, Cy M et al. (2016) Structural Characterization of the Extracellular Domain of CASPR2 and Insights into Its Association with the Novel Ligand Contactin1. J Biol Chem 291:5788-802
Yin, Xinghua; Kidd, Grahame J; Ohno, Nobuhiko et al. (2016) Proteolipid protein-deficient myelin promotes axonal mitochondrial dysfunction via altered metabolic coupling. J Cell Biol 215:531-542
Zhao, Claire Y; Greenstein, Joseph L; Winslow, Raimond L (2016) Roles of phosphodiesterases in the regulation of the cardiac cyclic nucleotide cross-talk signaling network. J Mol Cell Cardiol 91:215-27
Rajagopal, Vijay; Bass, Gregory; Walker, Cameron G et al. (2015) Examination of the Effects of Heterogeneous Organization of RyR Clusters, Myofibrils and Mitochondria on Ca2+ Release Patterns in Cardiomyocytes. PLoS Comput Biol 11:e1004417
Schachtrup, Christian; Ryu, Jae Kyu; Mammadzada, Könül et al. (2015) Nuclear pore complex remodeling by p75(NTR) cleavage controls TGF-? signaling and astrocyte functions. Nat Neurosci 18:1077-80
Sanders, Matthew A; Madoux, Franck; Mladenovic, Ljiljana et al. (2015) Endogenous and Synthetic ABHD5 Ligands Regulate ABHD5-Perilipin Interactions and Lipolysis in Fat and Muscle. Cell Metab 22:851-60
Takeshima, Hiroshi; Hoshijima, Masahiko; Song, Long-Sheng (2015) Ca²? microdomains organized by junctophilins. Cell Calcium 58:349-56
Mills, Elizabeth A; Davis, Chung-ha O; Bushong, Eric A et al. (2015) Astrocytes phagocytose focal dystrophies from shortening myelin segments in the optic nerve of Xenopus laevis at metamorphosis. Proc Natl Acad Sci U S A 112:10509-14
Kim, K-Y; Perkins, G A; Shim, M S et al. (2015) DRP1 inhibition rescues retinal ganglion cells and their axons by preserving mitochondrial integrity in a mouse model of glaucoma. Cell Death Dis 6:e1839

Showing the most recent 10 out of 382 publications