AUTHOR=Briatore Federica , Pregno Giulia , Di Angelantonio Silvia , Frola Elena , De Stefano Maria Egle , Vaillend Cyrille , Sassoè-Pognetto Marco , Patrizi Annarita TITLE=Dystroglycan Mediates Clustering of Essential GABAergic Components in Cerebellar Purkinje Cells JOURNAL=Frontiers in Molecular Neuroscience VOLUME=13 YEAR=2020 URL=https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2020.00164 DOI=10.3389/fnmol.2020.00164 ISSN=1662-5099 ABSTRACT=

Muscle dystrophin–glycoprotein complex (DGC) links the intracellular cytoskeleton to the extracellular matrix. In neurons, dystroglycan and dystrophin, two major components of the DGC, localize in a subset of GABAergic synapses, where their function is unclear. Here we used mouse models to analyze the specific role of the DGC in the organization and function of inhibitory synapses. Loss of full-length dystrophin in mdx mice resulted in a selective depletion of the transmembrane β-dystroglycan isoform from inhibitory post-synaptic sites in cerebellar Purkinje cells. Remarkably, there were no differences in the synaptic distribution of the extracellular α-dystroglycan subunit, of GABAA receptors and neuroligin 2. In contrast, conditional deletion of the dystroglycan gene from Purkinje cells caused a disruption of the DGC and severely impaired post-synaptic clustering of neuroligin 2, GABAA receptors and scaffolding proteins. Accordingly, whole-cell patch-clamp analysis revealed a significant reduction in the frequency and amplitude of spontaneous IPSCs recorded from Purkinje cells. In the long-term, deletion of dystroglycan resulted in a significant decrease of GABAergic innervation of Purkinje cells and caused an impairment of motor learning functions. These results show that dystroglycan is an essential synaptic organizer at GABAergic synapses in Purkinje cells.