There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
Inhibitory neurons play important roles in a number of brain functions. They are composed
of GABAergic neurons and glycinergic neurons, and vesicular GABA transporter (VGAT)
is specifically expressed in these neurons. Since the inhibitory neurons are scattered
around in the CNS, it is difficult to identify these cells in living brain preparations.
The glutamate decarboxylase (GAD) 67-GFP knock-in mouse has been widely used for the
identification of GABAergic neurons, but their GAD67 expression was decreased compared
to the wild-type mice. To overcome such a problem and to highlight the function and
morphology of inhibitory neurons, we generated four lines of VGAT-Venus transgenic
mice (lines #04, #29, #39 and #49) expressing Venus fluorescent protein under the
control of mouse VGAT promoter. We found higher expression level of Venus transcripts
and proteins as well as brighter fluorescent signal in line #39 mouse brains, compared
to brains of other lines examined. By Western blots and spectrofluorometric measurements
of forebrain, the line #39 mouse showed stronger GFP immunoreactivity and brighter
fluorescent intensity than the GAD67-GFP knock-in mouse. In addition, Venus was present
not only in somata, but also in neurites in the line #39 mouse by histological studies.
In situ hybridization analysis showed that the expression pattern of Venus in the
line #39 mouse was similar to that of endogenous VGAT. Double immunostaining analysis
in line #39 mouse showed that Venus-expressing cells are primarily immunoreactive
for GABA in cerebral cortex, hippocampus and cerebellar cortex and for GABA or glycine
in dorsal cochlear nucleus. These results demonstrate that the VGAT-Venus line #39
mouse should be useful for studies on function and morphology of inhibitory neurons
in the CNS.