title: Vesicular glutamate transporter-3 in the rodent brain: vesicular colocalization with vesicular γ-aminobutyric acid transporter.
abstract: Vesicular glutamate transporters (VGLUT1-3) carry glutamate into synaptic vesicles. VGLUT3 has been reported to be localized in nonglutamatergic neuronal populations in the brain. However, detailed subcellular localization of VGLUT3 has not been shown. In particular, the identity of synaptic vesicles expressing VGLUT3 remains to be revealed. Here we present novel electron microscopic postembedding immunogold data from mouse and rat brains showing that small, clear, and round synaptic vesicles in γ-aminobutyric acid (GABA)-ergic nerve terminals contain labeling for both VGLUT3 and the vesicular GABA transporter (VGAT). Immunoisolation of synaptic vesicles confirmed the immunogold data and showed vesicular colocalization of VGLUT3 and VGAT. Moreover, we show that gold particles signaling VGLUT3 are present in synaptic vesicles in acetylcholinergic nerve terminals in the striatum. Quantitative immunogold analyses reveal that the density of VGLUT3 gold particles is similar in GABAergic terminals in the hippocampus and the neocortex to that in cholinergic terminals in the striatum. In contrast to in the hippocampus and the neocortex, VGLUT3 was absent from VGAT-positive terminals in the striatum. The labeling pattern produced by the VGLUT3 antibodies was found to be specific; there was no labeling in VGLUT3 knockout tissue, and the observed labeling throughout the rat brain corresponds to the known light-microscopic distribution of VGLUT3. From the present results, we infer that glutamate is released with GABA from inhibitory terminals and acetylcholine from cholinergic terminals.
authors: Department of Anatomy, Institute of Basic Medical Sciences, and Centre for Molecular Biology and Neuroscience (CMBN), University of Oslo, 0317 Oslo, Norway.
authors: M J
authors: MJ
authors: Stensrud
authors: F A
authors: FA
authors: Chaudhry
authors: T B
authors: TB
authors: Leergaard
authors: J G
authors: JG
authors: Bjaalie
authors: V
authors: V
authors: Gundersen
mesh_terms: D026922:Amino Acid Transport Systems, Acidic / Q000172:deficiency / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016253:Microscopy, Immunoelectron; D051381:Rats; D017208:Rats, Wistar; D013572:Synaptic Vesicles / Q000378:metabolism / Q000648:ultrastructure; D050495:Vesicular Inhibitory Amino Acid Transport Proteins / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D026922:Amino Acid Transport Systems, Acidic; D002795:Choline O-Acetyltransferase; D049452:Green Fluorescent Proteins; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; C492244:Viaat protein, mouse; C485184:enhanced green fluorescent protein; C504941:Slc17a8 protein, mouse
keywords: VGLUT; brain; immunocytochemistry; neuron; rodent