Activity-induced ionotropic glutamate receptor dynamics at super-resolution in vivo

Project Description

The plastic properties of chemical neurotransmission enable glutamatergic synapses to regulate complex brain functions. While it is recognized that activity-dependent changes in synaptic strength can be mediated by reorganizations of ionotropic glutamate receptors, our knowledge of the molecular control of synaptic plasticity is far from complete. This is primarily due to several obstacles: (i) the size of protein assemblies at synapses is below the diffraction-limited resolution of conventional light microscopy and (ii) technical challenges obstruct the analysis of synapses in their natural physiological surroundings.

The present research proposal will engage recent technological innovations to meet these challenges. Focus will be placed on the plastic, developing, glutamatergic Drosophila neuromuscular junction to exploit its accessibility for molecular manipulations and in vivo imaging. Importantly, bi-directional dynamics of ionotropic glutamate receptors can be evoked at the NMJ by specific activity patterns.

We will use novel optogenetic effectors to trigger activity-dependent synaptic plasticity and super-resolution imaging via structured illumination microscopy (SIM), direct stochastic optical reconstruction microscopy (dSTORM) and photoactivated localization microscopy (PALM) to obtain quantitative information on the distribution and the movement of glutamate receptor subunits in semi-intact preparations and in vivo.

By synergistically combining these methodologies with electrophysiology, the research project aims to investigate how spatial and temporal activity patterns govern the subunit-specific mobility of synaptic glutamate receptors at nanoscopic resolution in the intact organism.

Title Year Authors Journal Links
Imaging cellular ultrastructures using expansion microscopy (U-ExM) 2019 Gambarotto, D., Zwettler, F. U., Le Guennec, M., Schmidt-Cernohorska, M., Fortun, D., Borgers, S., Heine, J., Schloetel, J.-G., Reuss, M., Unser, M., Boyden, E. S., Sauer, M., Hamel, V., and Guichard, P. Nat Methods More
Complexin cooperates with Bruchpilot to tether synaptic vesicles to the active zone cytomatrix 2019 Scholz, N., Ehmann, N., Sachidanandan, D., Imig, C., Cooper, B. H., Jahn, O., Reim, K., Brose, N., Meyer, J., Lamberty, M., Altrichter, S., Bormann, A., Hallermann, S., Pauli, M., Heckmann, M., Stigloher, C., Langenhan, T., and Kittel, R. J. J Cell Biol More
Synthetic light-activated ion channels for optogenetic activation and inhibition 2018 Beck, S., Yu-Strzelczyk, J., Pauls, D., Constantin, O. M., Gee, C. E., Ehmann, N., Kittel, R. J., Nagel, G., and Gao, S. Front Neurosci More
Bioorthogonal click chemistry enables site-specific fluorescence labeling of functional NMDA receptors for super-resolution imaging 2018 Neubert, F., Beliu, G., Terpitz, U., Werner C., Geis, C., Sauer, M., and Doose, S. Angew Chem Int Ed More
Mechano-dependent signaling by Latrophilin/CIRL quenches cAMP in proprioceptive neurons 2017 Scholz, N., Guan, C., Nieberler, M., Grotemeyer, A., Maiellaro, I., Gao, S., Beck, S., Pawlak, M., Sauer, M., Asan, E., Rothemund, S., Winkler, J., Prömel, S., Nagel, G., Langenhan, T., and Kittel, R. J. eLife More
Single-molecule localization microscopy in eukaryotes 2017 Sauer, M., and Heilemann, M. Chem Rev More
Drosophila active zones: From molecules to behaviour. 2017 Ehmann, N., Owald, D., and Kittel, R.J. Neurosci Res More
cAMP Signals in Drosophila Motor Neurons Are Confined to Single Synaptic Boutons 2016 Maiellaro, I., Lohse, M. J., Kittel, R. J. and Calebiro, D. Cell Rep More
Synaptic Vesicle Proteins and Active Zone Plasticity 2016 Kittel, R. J. and Heckmann, M. Front Synaptic Neurosci More
Adhesion GPCRs as a putative class of metabotropic mechanosensors 2016 Scholz, N., Monk, K. R., Kittel, R. J., Langenhan, T. Handb Exp Pharmacol More
Control of adhesion GPCR function through proteolytic processing 2016 Nieberler, M., Kittel, R. J., Petrenko, A. G., Lin, H. H., Langenhan, T. Handb Exp Pharmacol More
Human autoantibodies to amphiphysin induce defective presynaptic vesicle dynamics and composition 2016 Werner, C., Pauli, M., Doose, S., Weishaupt, A., Haselmann, H., Grunewald, B., Sauer, M., Heckmann, M., Toyka, K. V., Asan, E., Sommer, C., and Geis, C. Brain More
Quantitative super-resolution imaging of Bruchpilot distinguishes active zone states 2014 Ehmann, N., van de Linde, S., Alon, A., Ljaschenko, D., Keung, X. Z., Holm, T., Rings, A., DiAntonio, A., Hallermann, S., Ashery, U., Heckmann, M., Sauer, M. and Kittel, R. J. Nat Commun More
Channelrhodopsin-2-XXL, a powerful optogenetic tool for low light applications 2014 Dawydow, A., Gueta, R., Ljaschenko, D., Ullrich, S., Hermann, M., Ehmann, N., Gao, S., Fiala, A., Langenhan, T., Nagel, G., Kittel, R.J. Proc Natl Acad Sci USA More
Hebbian plasticity guides maturation of glutamate receptor fields in vivo 2013 Ljaschenko, D., Ehmann, N. and Kittel, R. J. Cell Rep More
rapidSTORM: accurate, fast open-source software for localization microscopy 2012 Wolter, S., Löschberger, A., Holm, T., Aufmkolk, S., Dabauvalle, M.-C., van de Linde, S. and Sauer, M. Nat Methods More
Super-resolution imaging visualizes the eightfold symmetry of gp210 proteins around the nuclear pore complex and resolves the central channel with nanometer resolution 2012 Löschberger, A., S. van de Linde, M. C. Dabauvalle, B. Rieger, M. Heilemann, Krohne, G. and Sauer, M. J Cell Sci More
Direct stochastic optical reconstruction microscopy with standard fluorescent probes 2011 van de Linde, S., Löschberger, A., Klein, T., Heidbreder, M., Wolter, S., Heilemann, M. and Sauer, M. Nat Protoc More
Live-cell super-resolution imaging with trimethoprim conjugates 2010 Wombacher, R., M. Heidbreder, S. van de Linde, M.P. Sheetz, M. Heilemann, Cornish, V. W. and Sauer, M. Nat Methods More
Activity-dependent site-specific changes of glutamate receptor composition in vivo 2008 Schmid, A., Hallermann, S., Kittel, R. J., Khorramshahi, O., Frölich, A. M. J., Quentin, C., Rasse, T. M., Mertel, S., Heckmann, M. and Sigrist, S. J. Nat Neurosci More
Subdiffraction-resolution fluorescence imaging with conventional fluorescent probes 2008 Heilemann, M., van de Linde, S., Schüttpelz, M., Kasper, R., Seefeldt, B., Mukherjee, A., Tinnefeld, P. and Sauer, M. Angew Chem Int Ed More
Bruchpilot promotes active zone assembly, Ca2+ channel clustering, and vesicle release 2006 Kittel RJ, Wichmann C, Rasse TM, Fouquet W, Schmidt M, Schmid A, Wagh DA, Pawlu C, Kellner RR, Willig KI, Hell SW, Buchner E, Heckmann M, Sigrist SJ. Science More