VGLUT1 is localized in astrocytic processes in several brain regions

TY - JOUR

T1 - VGLUT1 is localized in astrocytic processes in several brain regions

AU - Ormel, Lasse

AU - Stensrud, Mats Julius

AU - Bergersen, Linda Hildegard

AU - Gundersen, Vidar

N1 - Copyright © 2011 Wiley Periodicals, Inc.

PY - 2012/2

Y1 - 2012/2

N2 - During the last years, the concept of gliotransmission has been established. Glutamate has been shown to be released from astrocytes by different mechanisms, e.g., in an exocytotic manner. The authors have previously shown that astrocytes in the dentate-molecular layers express vesicular glutamate transporters on synaptic-like microvesicles (SLMVs). By confocal microscopy, the authors, in this study, show that vesicles by a family of glutamate transporters 1 (VGLUT1) labeling was clearly present within astrocytic processes (diameter > 1 μm) in several brain regions; the dentate-molecular layers, the stratum radiatum of CA1 hippocampus, the frontal cortex, and the striatum. At the electron microscopic level, immunogold cytochemistry showed the presence of VGLUT1 gold particles over SLMVs in delicate astrocytic processes (cross-sectional diameter < 500 nm) in all the above-mentioned brain regions. When measuring the distance from the membrane of SLMVs in astrocytes to the closest VGLUT1 gold particle, it turned out that most gold particles (above 95 %) were located within 25 nm from the membrane, strongly suggesting that VGLUT1 is present in SLMVs in the astrocytes. Finally, electron microscopic immunocytochemistry shows that VGLUT1 labeling was concentrated in astrocytic processes from wild type, and not in VGLUT1 knock out hippocampus. The authors have concluded that astrocytes not only in the dentate-molecular layers but also in stratum radiatum of CA1 hippocampus, frontal cortex, and the striatum possess SLMVs carrying VGLUT1, suggesting that astrocytes in all these brain regions are capable of vesicular release of glutamate.

AB - During the last years, the concept of gliotransmission has been established. Glutamate has been shown to be released from astrocytes by different mechanisms, e.g., in an exocytotic manner. The authors have previously shown that astrocytes in the dentate-molecular layers express vesicular glutamate transporters on synaptic-like microvesicles (SLMVs). By confocal microscopy, the authors, in this study, show that vesicles by a family of glutamate transporters 1 (VGLUT1) labeling was clearly present within astrocytic processes (diameter > 1 μm) in several brain regions; the dentate-molecular layers, the stratum radiatum of CA1 hippocampus, the frontal cortex, and the striatum. At the electron microscopic level, immunogold cytochemistry showed the presence of VGLUT1 gold particles over SLMVs in delicate astrocytic processes (cross-sectional diameter < 500 nm) in all the above-mentioned brain regions. When measuring the distance from the membrane of SLMVs in astrocytes to the closest VGLUT1 gold particle, it turned out that most gold particles (above 95 %) were located within 25 nm from the membrane, strongly suggesting that VGLUT1 is present in SLMVs in the astrocytes. Finally, electron microscopic immunocytochemistry shows that VGLUT1 labeling was concentrated in astrocytic processes from wild type, and not in VGLUT1 knock out hippocampus. The authors have concluded that astrocytes not only in the dentate-molecular layers but also in stratum radiatum of CA1 hippocampus, frontal cortex, and the striatum possess SLMVs carrying VGLUT1, suggesting that astrocytes in all these brain regions are capable of vesicular release of glutamate.

KW - Animals

KW - Astrocytes/metabolism

KW - CA1 Region, Hippocampal/metabolism

KW - Cell Compartmentation/genetics

KW - Corpus Striatum/metabolism

KW - Cytoplasmic Vesicles/genetics

KW - Dentate Gyrus/metabolism

KW - Frontal Lobe/metabolism

KW - Male

KW - Mice

KW - Mice, Knockout

KW - Rats

KW - Rats, Wistar

KW - Vesicular Glutamate Transport Protein 1/deficiency

U2 - 10.1002/glia.21258

DO - 10.1002/glia.21258

M3 - Journal article

C2 - 22009457

SN - 0894-1491

VL - 60

SP - 229

EP - 238

JO - Glia

JF - Glia

IS - 2

ER -