Microglia remodel synapses by presynaptic trogocytosis and spine head filopodia induction
Dr. Cornelius Gross, Miss Laetitia Weinhard , Urte Neniskyte , Giulia di Bartolomei , Dr. Giulia Bolasco , Pedro Machado , Dr. Nicole Schieber , Melanie Exiga , Auguste Vadisiute , Dr. Angelo Raggioli , Dr. Andreas Schertel , Dr. Yannick Schwab
Received: 8th September 17
Microglia are highly motile glial cells that are proposed to mediate synaptic pruning during neuronal circuit formation. Disruption of signaling between microglia and neurons leads to an excess of immature synaptic connections, thought to be the result of impaired phagocytosis of synapses by microglia. However, until now the direct phagocytosis of synapses by microglia has not been reported and fundamental questions remain about the precise synaptic structures and phagocytic mechanisms involved. Here we used light sheet fluorescence microscopy to follow microglia-synapse interactions in developing organotypic hippocampal cultures, complemented by three-dimensional ultrastructural characterization using correlative light and electron microscopy (CLEM). Our findings define a set of dynamic microglia-synapse interactions, including the selective partial phagocytosis, or trogocytosis (trogo-: nibble), of presynaptic structures and the induction of postsynaptic spine head filopodia by microglia. These findings allow us to propose a mechanism for the facilitatory role of microglia in synaptic circuits remodeling and maturation.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.