RT Journal Article
SR Electronic
T1 <em>In Vivo</em> Imaging of Intersynaptic Vesicle Exchange Using VGLUT1<sup>Venus</sup> Knock-In Mice
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 15544
OP 15559
DO 10.1523/JNEUROSCI.2073-11.2011
VO 31
IS 43
A1 Etienne Herzog
A1 Fabien Nadrigny
A1 Katlin Silm
A1 Christoph Biesemann
A1 Imke Helling
A1 Tiphaine Bersot
A1 Heinz Steffens
A1 Richard Schwartzmann
A1 U. Valentin Nägerl
A1 Salah El Mestikawy
A1 JeongSeop Rhee
A1 Frank Kirchhoff
A1 Nils Brose
YR 2011
UL http://www.jneurosci.org/content/31/43/15544.abstract
AB The vesicular glutamate transporter VGLUT1 loads synaptic vesicles with the neurotransmitter glutamate and thereby determines glutamate release at many synapses in the mammalian brain. Due to its function and selective localization, VGLUT1 is one of the most specific markers for glutamatergic synaptic vesicles. It has been used widely to identify glutamatergic synapses, and its expression levels are tightly correlated with changes in quantal size, modulations of synaptic plasticity, and corresponding behaviors. We generated a fluorescent VGLUT1Venus knock-in mouse for the analysis of VGLUT1 and glutamatergic synaptic vesicle trafficking. The mutation does not affect glutamatergic synapse function, and thus the new mouse model represents a universal tool for the analysis of glutamatergic transmitter systems in the forebrain. Previous studies demonstrated synaptic vesicle exchange between terminals in vitro. Using the VGLUT1Venus knock-in, we show that synaptic vesicles are dynamically shared among boutons in the cortex of mice in vivo. We provide a detailed analysis of synaptic vesicle sharing in vitro, and show that network homeostasis leads to dynamic scaling of synaptic VGLUT1 levels.