Activity-Dependent Remodeling of Synaptic Protein Organization Revealed by High Throughput Analysis of STED Nanoscopy Images.

TitleActivity-Dependent Remodeling of Synaptic Protein Organization Revealed by High Throughput Analysis of STED Nanoscopy Images.
Publication TypeJournal Article
Year of Publication2020
AuthorsWiesner T, Bilodeau A, Bernatchez R, Deschênes A, Raulier B, De Koninck P, Lavoie-Cardinal F
JournalFront Neural Circuits
Volume14
Pagination57
Date Published2020
ISSN1662-5110
Abstract

The organization of proteins in the apposed nanodomains of pre- and postsynaptic compartments is thought to play a pivotal role in synaptic strength and plasticity. As such, the alignment between pre- and postsynaptic proteins may regulate, for example, the rate of presynaptic release or the strength of postsynaptic signaling. However, the analysis of these structures has mainly been restricted to subsets of synapses, providing a limited view of the diversity of synaptic protein cluster remodeling during synaptic plasticity. To characterize changes in the organization of synaptic nanodomains during synaptic plasticity over a large population of synapses, we combined STimulated Emission Depletion (STED) nanoscopy with a Python-based statistical object distance analysis (pySODA), in dissociated cultured hippocampal circuits exposed to treatments driving different forms of synaptic plasticity. The nanoscale organization, characterized in terms of coupling properties, of presynaptic (Bassoon, RIM1/2) and postsynaptic (PSD95, Homer1c) scaffold proteins was differently altered in response to plasticity-inducing stimuli. For the Bassoon - PSD95 pair, treatments driving synaptic potentiation caused an increase in their coupling probability, whereas a stimulus driving synaptic depression had an opposite effect. To enrich the characterization of the synaptic cluster remodeling at the population level, we applied unsupervised machine learning approaches to include selected morphological features into a multidimensional analysis. This combined analysis revealed a large diversity of synaptic protein cluster subtypes exhibiting differential activity-dependent remodeling, yet with common features depending on the expected direction of plasticity. The expanded palette of synaptic features revealed by our unbiased approach should provide a basis to further explore the widely diverse molecular mechanisms of synaptic plasticity.

DOI10.3389/fncir.2020.00057
Alternate JournalFront Neural Circuits
PubMed ID33177994
PubMed Central IDPMC7594516
Grant List378058 / / CIHR / Canada

Funding

Our research endeavors are made possible by the following agencies:

Canadian Institutes of Health Research - Instituts de recherche en santé du Canada Fonds de recherche du Québec – Nature et technologies (FRQNT)Fonds de la recherche en santé du Québec   Natural Sciences and Engineering Research Council of Canada (NSERC) - Conseil de recherche en sciences naturelles et en génie du Canada (CRSNG)innovation.caHuman Frontier Science ProgramCanada First Research Excellence FundSentinelle Nord