TY - JOUR
T1 - Coexpression of vesicular glutamate transporters 1 and 2, glutamic acid decarboxylase and calretinin in rat entorhinal cortex
AU - Wouterlood, Floris G
AU - Canto, Cathrin B
AU - Aliane, Verena
AU - Boekel, Amber J
AU - Grosche, Jens
AU - Härtig, Wolfgang
AU - Beliën, Jeroen A M
AU - Witter, Menno P
PY - 2007
Y1 - 2007
N2 - We studied the distribution and coexpression of vesicular glutamate transporters (VGluT1, VGluT2), glutamic acid decarboxylase
(GAD) and calretinin (CR, calcium-binding protein) in rat entorhinal cortex, using immunofluorescence staining and multichannel
confocal laser scanning microscopy. Images were computer processed and subjected to automated 3D object recognition, colocalization
analysis and 3D reconstruction. Since the VGluTs (in contrast to CR and GAD) occurred in fibers and axon terminals only, we
focused our attention on these neuronal processes. An intense, punctate VGluT1-staining occurred everywhere in the entorhinal
cortex. Our computer program resolved these punctae as small 3D objects. Also VGluT2 showed a punctate immunostaining pattern,
yet with half the number of 3D objects per tissue volume compared with VGluT1, and with statistically significantly larger
3D objects. Both VGluTs were distributed homogeneously across cortical layers, with in MEA VGluT1 slightly more densely distributed
than in LEA. The distribution pattern and the size distribution of GAD 3D objects resembled that of VGluT2. CR-immunopositive
fibers were abundant in all cortical layers. In double-stained sections we noted ample colocalization of CR and VGluT2, whereas
coexpression of CR and VGluT1 was nearly absent. Also in triple-staining experiments (VGluT2, GAD and CR combined) we noted
coexpression of VGluT2 and CR and, in addition, frequent coexpression of GAD and CR. Modest colocalization occurred of VGluT2
and GAD, and incidental colocalization of all three markers. We conclude that the CR-containing axon terminals in the entorhinal
cortex belong to at least two subpopulations of CR-neurons: a glutamatergic excitatory and a GABAergic inhibitory.
AB - We studied the distribution and coexpression of vesicular glutamate transporters (VGluT1, VGluT2), glutamic acid decarboxylase
(GAD) and calretinin (CR, calcium-binding protein) in rat entorhinal cortex, using immunofluorescence staining and multichannel
confocal laser scanning microscopy. Images were computer processed and subjected to automated 3D object recognition, colocalization
analysis and 3D reconstruction. Since the VGluTs (in contrast to CR and GAD) occurred in fibers and axon terminals only, we
focused our attention on these neuronal processes. An intense, punctate VGluT1-staining occurred everywhere in the entorhinal
cortex. Our computer program resolved these punctae as small 3D objects. Also VGluT2 showed a punctate immunostaining pattern,
yet with half the number of 3D objects per tissue volume compared with VGluT1, and with statistically significantly larger
3D objects. Both VGluTs were distributed homogeneously across cortical layers, with in MEA VGluT1 slightly more densely distributed
than in LEA. The distribution pattern and the size distribution of GAD 3D objects resembled that of VGluT2. CR-immunopositive
fibers were abundant in all cortical layers. In double-stained sections we noted ample colocalization of CR and VGluT2, whereas
coexpression of CR and VGluT1 was nearly absent. Also in triple-staining experiments (VGluT2, GAD and CR combined) we noted
coexpression of VGluT2 and CR and, in addition, frequent coexpression of GAD and CR. Modest colocalization occurred of VGluT2
and GAD, and incidental colocalization of all three markers. We conclude that the CR-containing axon terminals in the entorhinal
cortex belong to at least two subpopulations of CR-neurons: a glutamatergic excitatory and a GABAergic inhibitory.
KW - Animals
KW - Calbindin 2
KW - Entorhinal Cortex
KW - Female
KW - Glutamate Decarboxylase
KW - Imaging, Three-Dimensional
KW - Neurons
KW - Rats
KW - Rats, Wistar
KW - S100 Calcium Binding Protein G
KW - Vesicular Glutamate Transport Protein 1
KW - Vesicular Glutamate Transport Protein 2
KW - Journal Article
KW - Research Support, Non-U.S. Gov't
U2 - 10.1007/s00429-007-0163-z
DO - 10.1007/s00429-007-0163-z
M3 - Article
C2 - 17965879
VL - 212
SP - 303
EP - 319
JO - Brain Structure and Function
JF - Brain Structure and Function
SN - 1863-2653
IS - 3
ER -