Synaptic and vesicular co-localization of the glutamate transporters VGLUT1 and VGLUT2 in the mouse hippocampus.
J Neurochem. 2006-11-01; 99(3): 1011-1018
DOI: 10.1111/j.1471-4159.2006.04144.x
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1. J Neurochem. 2006 Nov;99(3):1011-8. Epub 2006 Aug 29.
Synaptic and vesicular co-localization of the glutamate transporters VGLUT1 and
VGLUT2 in the mouse hippocampus.
Herzog E(1), Takamori S, Jahn R, Brose N, Wojcik SM.
Author information:
(1)Max Planck Institut für Experimentelle Medizin, Abteilung Molekulare
Neurobiologie,Göttingen, Germany.
Vesicular glutamate transporters (VGLUTs) are essential to glutamatergic synapses
and determine the glutamatergic phenotype of neurones. The three known VGLUT
isoforms display nearly identical uptake characteristics, but the associated
expression domains in the adult rodent brain are largely segregated. Indeed,
indirect evidence obtained in young VGLUT1-deficient mice indicated that in cells
that co-express VGLUT1 and VGLUT2, the transporters may be targeted to different
synaptic vesicles, which may populate different types of synapses formed by the
same neurone. Direct evidence for a systematic segregation of VGLUT1 and VGLUT2
to distinct synapses and vesicles is lacking, and the mechanisms that may convey
this segregation are not known. We show here that VGLUT1 and VGLUT2 are
co-localized in many layers of the young hippocampus. Strikingly, VGLUT2
co-localizes with VGLUT1 in the mossy fibers at early stages. Furthermore, we
show that a fraction of VGLUT1 and VGLUT2 is carried by the same vesicles at
these stages. Hence, hippocampal neurones co-expressing VGLUT1 and VGLUT2 do not
appear to sort them to separate vesicle pools. As the number of transporter
molecules per vesicle affects quantal size, the developmental window where VGLUT1
and VGLUT2 are co-expressed may allow for greater plasticity in the control of
quantal release.
DOI: 10.1111/j.1471-4159.2006.04144.x
PMID: 16942593 [Indexed for MEDLINE]