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Presence of the vesicular inhibitory amino acid transporter in GABAergic and glycinergic synaptic terminal boutons
- Source :
- Europe PubMed Central
- Publication Year :
- 1999
-
Abstract
- The characterization of the Caenorhabditis elegans unc-47 gene recently allowed the identification of a mammalian (gamma)-amino butyric acid (GABA) transporter, presumed to be located in the synaptic vesicle membrane. In situ hybridization data in rat brain suggested that it might also take up glycine and thus represent a general Vesicular Inhibitory Amino Acid Transporter (VIAAT). In the present study, we have investigated the localization of VIAAT in neurons by using a polyclonal antibody raised against the hydrophilic N-terminal domain of the protein. Light microscopy and immunocytochemistry in primary cultures or tissue sections of the rat spinal cord revealed that VIAAT was localized in a subset (63-65%) of synaptophysin-immunoreactive terminal boutons; among the VIAAT-positive terminals around motoneuronal somata, 32.9% of them were also immunoreactive for GAD65, a marker of GABAergic presynaptic endings. Labelling was also found apposed to clusters positive for the glycine receptor or for its associated protein gephyrin. At the ultrastructural level, VIAAT immunoreactivity was restricted to presynaptic boutons exhibiting classical inhibitory features and, within the boutons, concentrated over synaptic vesicle clusters. Pre-embedding detection of VIAAT followed by post-embedding detection of GABA or glycine on serial sections of the spinal cord or cerebellar cortex indicated that VIAAT was present in glycine-, GABA- or GABA- and glycine-containing boutons. Taken together, these data further support the view of a common vesicular transporter for these two inhibitory transmitters, which would be responsible for their costorage in the same synaptic vesicle and subsequent corelease at mixed GABA-and-glycine synapses.
- Subjects :
- Amino Acid Transport Systems
Vesicular Inhibitory Amino Acid Transport Proteins
Glycine
Presynaptic Terminals
Vesicular Transport Proteins
Biology
Inhibitory postsynaptic potential
Transfection
Synaptic vesicle
Rats, Sprague-Dawley
Mice
Antibody Specificity
Animals
Microscopy, Immunoelectron
Glycine receptor
Cells, Cultured
gamma-Aminobutyric Acid
Neurons
Gephyrin
Synaptic vesicle membrane
Cell Biology
Embryo, Mammalian
Immunohistochemistry
Cell biology
Rats
Vesicular transport protein
nervous system
Biochemistry
Spinal Cord
Cerebellar cortex
COS Cells
biology.protein
GABAergic
Rabbits
Carrier Proteins
Subjects
Details
- ISSN :
- 00219533
- Volume :
- 112
- Database :
- OpenAIRE
- Journal :
- Journal of cell science
- Accession number :
- edsair.doi.dedup.....2c587ead86fed295fef48b1379ca7aef