Immunogold detection of L-glutamate and D-serine in small synaptic-like microvesicles in adult hippocampal astrocytes

TY - JOUR

T1 - Immunogold detection of L-glutamate and D-serine in small synaptic-like microvesicles in adult hippocampal astrocytes

AU - Bergersen, L H

AU - Morland, C

AU - Ormel, L

AU - Rinholm, J E

AU - Larsson, M

AU - Wold, J F H

AU - Røe, A T

AU - Stranna, A

AU - Santello, M

AU - Bouvier, D

AU - Ottersen, O P

AU - Volterra, A

AU - Gundersen, V

PY - 2012/7

Y1 - 2012/7

N2 - Glutamate and the N-methyl-D-aspartate receptor ligand D-serine are putative gliotransmitters. Here, we show by immunogold cytochemistry of the adult hippocampus that glutamate and D-serine accumulate in synaptic-like microvesicles (SLMVs) in the perisynaptic processes of astrocytes. The estimated concentration of fixed glutamate in the astrocytic SLMVs is comparable to that in synaptic vesicles of excitatory nerve terminals (≈ 45 and ≈ 55 mM, respectively), whereas the D-serine level is about 6 mM. The vesicles are organized in small spaced clusters located near the astrocytic plasma membrane. Endoplasmic reticulum is regularly found in close vicinity to SLMVs, suggesting that astrocytes contain functional nanodomains, where a local Ca(2+) increase can trigger release of glutamate and/or D-serine.

AB - Glutamate and the N-methyl-D-aspartate receptor ligand D-serine are putative gliotransmitters. Here, we show by immunogold cytochemistry of the adult hippocampus that glutamate and D-serine accumulate in synaptic-like microvesicles (SLMVs) in the perisynaptic processes of astrocytes. The estimated concentration of fixed glutamate in the astrocytic SLMVs is comparable to that in synaptic vesicles of excitatory nerve terminals (≈ 45 and ≈ 55 mM, respectively), whereas the D-serine level is about 6 mM. The vesicles are organized in small spaced clusters located near the astrocytic plasma membrane. Endoplasmic reticulum is regularly found in close vicinity to SLMVs, suggesting that astrocytes contain functional nanodomains, where a local Ca(2+) increase can trigger release of glutamate and/or D-serine.

KW - Animals

KW - Astrocytes/metabolism

KW - Cells, Cultured

KW - Glutamic Acid/metabolism

KW - Gold

KW - Hippocampus/metabolism

KW - Immunohistochemistry/methods

KW - Rats

KW - Rats, Wistar

KW - Serine/metabolism

KW - Synaptic Vesicles/metabolism

U2 - 10.1093/cercor/bhr254

DO - 10.1093/cercor/bhr254

M3 - Journal article

C2 - 21914633

SN - 1047-3211

VL - 22

SP - 1690

EP - 1697

JO - Cerebral Cortex

JF - Cerebral Cortex

IS - 7

ER -