Characterization of MSB synapses in dissociated hippocampal culture with simultaneous pre- and postsynaptic live microscopy.
Multisynaptic boutons (MSBs) are presynaptic boutons in contact with multiple postsynaptic partners. Although MSB synapses have been studied with static imaging techniques such as electron microscopy (EM), the dynamics of individual MSB synapses have not been directly evaluated. It is known that the number of MSB synapses increases with synaptogenesis and plasticity but the formation, behavior, and fate of individual MSB synapses remains largely unknown. To address this, we developed a means of live imaging MSB synapses to observe them directly over time. With time lapse confocal microscopy of GFP-filled dendrites in contact with VAMP2-DsRed-labeled boutons, we recorded both MSBs and their contacting spines hourly over 15 or more hours. Our live microscopy showed that, compared to spines contacting single synaptic boutons (SSBs), MSB-contacting spines exhibit elevated dynamic behavior. These results are consistent with the idea that MSBs serve as intermediates in synaptic development and plasticity.
Department of Neuroscience, Mount Sinai School of Medicine, New York City, New York, United States of America.
James E
JE
Reilly
Hugo H
HH
Hanson
Mónica
M
Fernández-Monreal
Susan L
SL
Wearne
Patrick R
PR
Hof
Greg R
GR
Phillips
D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods*; D002470:Cell Survival; D049229:Dendritic Spines / Q000378:metabolism; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology*; D008853:Microscopy / Q000379:methods*; D011247:Pregnancy; D017729:Presynaptic Terminals / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D005456:Fluorescent Dyes