Limits...
ARG3.1/ARC expression in hippocampal dentate gyrus astrocytes: ultrastructural evidence and co-localization with glial fibrillary acidic protein.

Rodríguez JJ, Davies HA, Errington ML, Verkhratsky A, Bliss TV, Stewart MG - J. Cell. Mol. Med. (2008)

Bottom Line: Arg3.1/Arc protein was originally considered neurone specific; however, we have recently found Arg3.1/Arc immunoreactivity (Arg3.1/Arc-IR) within glial cells and demonstrated its increased expression after LTP in the hippocampal dentate gyrus (DG).Arc-IR was distributed throughout the cytoplasm, often associated with GFAP filaments, and along the plasma membrane of glial processes.These data, taken with our earlier study which provided evidence for an increase in astrocytic Arg3.1/Arc-IR after the induction of LTP, suggest a role for glial Arg3.1/Arc in structural and synaptic plasticity which may be critical for the maintenance of cognitive functions.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Life Sciences, The University of Manchester, Manchester, UK. Jose.Rodriguez-arellano@manchester.ac.uk

ABSTRACT
Synaptic efficacy following long-term potentiation (LTP) and memory consolidation is associated with changes in the expression of immediate early genes (IEGs). These changes are often accompanied by increased expression of glial fibrillary acidic protein (GFAP). While the protein products of the majority of IEGs are mainly restricted to the cell body, Arg3.1/Arc product is rapidly delivered to dendrites, where it accumulates close to synaptic sites. Arg3.1/Arc protein was originally considered neurone specific; however, we have recently found Arg3.1/Arc immunoreactivity (Arg3.1/Arc-IR) within glial cells and demonstrated its increased expression after LTP in the hippocampal dentate gyrus (DG). Here, we have further investigated this novel finding, using electron microscopic immunocytochemistry to determine the localization and sub-cellular distribution of Arg3.1/Arc protein in GFAP positive glia (GFAP-IR) in the DG. Arg3.1/Arc labelling was seen prominently in GFAP-IR glial cell bodies and in large- and medium-sized glial filamentous processes. GFAP-labelled medium-small peri-synaptic glial profiles also displayed Arg3.1/Arc-IR; however, the very thin and distal glial filaments only displayed Arc-IR. Arc-IR was distributed throughout the cytoplasm, often associated with GFAP filaments, and along the plasma membrane of glial processes. Peri-synaptic glial Arg3.1/Arc-IR processes were apposed to pre- and/or post-synaptic profiles at asymmetric axospinous synapses. These data, taken with our earlier study which provided evidence for an increase in astrocytic Arg3.1/Arc-IR after the induction of LTP, suggest a role for glial Arg3.1/Arc in structural and synaptic plasticity which may be critical for the maintenance of cognitive functions.

Show MeSH

Related in: MedlinePlus

Photomicrographs showing Arc protein expression throughout the dentate gyrus in both, rat (A) and mice (B). Arc protein is present in the granule cells (red asterisks) as well as targeted to their proximal dendrites (curved arrows) and other scattered processes throughout the ML (arrows). C-D: Photomicrographs showing dentate gyrus GFAP and Arg3.1/Arc. Immunogold labelling for GFAP in round (C 1 and 2) and stellate cells (D 1-3) that also show brown peroxidase reaction product identifying Arg3.1/Arc (C and D boxed regions). Gold GFAP labelling is also seen in numerous cells and processes within the different layers of the DG (arrows), which is without Arg3.1/Arc peroxidase reaction product. Scale bars = 100 μm in A and B, 50 μm in C and D and 10 μm in insets.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3822552&req=5

fig01: Photomicrographs showing Arc protein expression throughout the dentate gyrus in both, rat (A) and mice (B). Arc protein is present in the granule cells (red asterisks) as well as targeted to their proximal dendrites (curved arrows) and other scattered processes throughout the ML (arrows). C-D: Photomicrographs showing dentate gyrus GFAP and Arg3.1/Arc. Immunogold labelling for GFAP in round (C 1 and 2) and stellate cells (D 1-3) that also show brown peroxidase reaction product identifying Arg3.1/Arc (C and D boxed regions). Gold GFAP labelling is also seen in numerous cells and processes within the different layers of the DG (arrows), which is without Arg3.1/Arc peroxidase reaction product. Scale bars = 100 μm in A and B, 50 μm in C and D and 10 μm in insets.

Mentions: Two anti-Arg3.1/Arc anti-sera were used. (1) An Arg3.1/Arc polyclonal affinity-purified rabbit anti-serum raised against His6-Arg3.1/Arc recombinant protein comprising amino acids 130–396 (gift of Dr. D. Kuhl) and (2) A polyclonal affinity-purified goat anti-serum raised against a peptide mapping the N-terminus (amino acids 1–50) of rat Arc protein was obtained from Santa Cruz Biotechnology Inc. (E-19, sc-6382, Santa Cruz, CA, USA). The pattern of labelling obtained with both antibodies is consistent with the immunolabelling observed with our previous study as well as other Arg3.1/Arc antibodies (Fig. 1A and B) [1, 4].


ARG3.1/ARC expression in hippocampal dentate gyrus astrocytes: ultrastructural evidence and co-localization with glial fibrillary acidic protein.

Rodríguez JJ, Davies HA, Errington ML, Verkhratsky A, Bliss TV, Stewart MG - J. Cell. Mol. Med. (2008)

Photomicrographs showing Arc protein expression throughout the dentate gyrus in both, rat (A) and mice (B). Arc protein is present in the granule cells (red asterisks) as well as targeted to their proximal dendrites (curved arrows) and other scattered processes throughout the ML (arrows). C-D: Photomicrographs showing dentate gyrus GFAP and Arg3.1/Arc. Immunogold labelling for GFAP in round (C 1 and 2) and stellate cells (D 1-3) that also show brown peroxidase reaction product identifying Arg3.1/Arc (C and D boxed regions). Gold GFAP labelling is also seen in numerous cells and processes within the different layers of the DG (arrows), which is without Arg3.1/Arc peroxidase reaction product. Scale bars = 100 μm in A and B, 50 μm in C and D and 10 μm in insets.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3822552&req=5

fig01: Photomicrographs showing Arc protein expression throughout the dentate gyrus in both, rat (A) and mice (B). Arc protein is present in the granule cells (red asterisks) as well as targeted to their proximal dendrites (curved arrows) and other scattered processes throughout the ML (arrows). C-D: Photomicrographs showing dentate gyrus GFAP and Arg3.1/Arc. Immunogold labelling for GFAP in round (C 1 and 2) and stellate cells (D 1-3) that also show brown peroxidase reaction product identifying Arg3.1/Arc (C and D boxed regions). Gold GFAP labelling is also seen in numerous cells and processes within the different layers of the DG (arrows), which is without Arg3.1/Arc peroxidase reaction product. Scale bars = 100 μm in A and B, 50 μm in C and D and 10 μm in insets.
Mentions: Two anti-Arg3.1/Arc anti-sera were used. (1) An Arg3.1/Arc polyclonal affinity-purified rabbit anti-serum raised against His6-Arg3.1/Arc recombinant protein comprising amino acids 130–396 (gift of Dr. D. Kuhl) and (2) A polyclonal affinity-purified goat anti-serum raised against a peptide mapping the N-terminus (amino acids 1–50) of rat Arc protein was obtained from Santa Cruz Biotechnology Inc. (E-19, sc-6382, Santa Cruz, CA, USA). The pattern of labelling obtained with both antibodies is consistent with the immunolabelling observed with our previous study as well as other Arg3.1/Arc antibodies (Fig. 1A and B) [1, 4].

Bottom Line: Arg3.1/Arc protein was originally considered neurone specific; however, we have recently found Arg3.1/Arc immunoreactivity (Arg3.1/Arc-IR) within glial cells and demonstrated its increased expression after LTP in the hippocampal dentate gyrus (DG).Arc-IR was distributed throughout the cytoplasm, often associated with GFAP filaments, and along the plasma membrane of glial processes.These data, taken with our earlier study which provided evidence for an increase in astrocytic Arg3.1/Arc-IR after the induction of LTP, suggest a role for glial Arg3.1/Arc in structural and synaptic plasticity which may be critical for the maintenance of cognitive functions.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Life Sciences, The University of Manchester, Manchester, UK. Jose.Rodriguez-arellano@manchester.ac.uk

ABSTRACT
Synaptic efficacy following long-term potentiation (LTP) and memory consolidation is associated with changes in the expression of immediate early genes (IEGs). These changes are often accompanied by increased expression of glial fibrillary acidic protein (GFAP). While the protein products of the majority of IEGs are mainly restricted to the cell body, Arg3.1/Arc product is rapidly delivered to dendrites, where it accumulates close to synaptic sites. Arg3.1/Arc protein was originally considered neurone specific; however, we have recently found Arg3.1/Arc immunoreactivity (Arg3.1/Arc-IR) within glial cells and demonstrated its increased expression after LTP in the hippocampal dentate gyrus (DG). Here, we have further investigated this novel finding, using electron microscopic immunocytochemistry to determine the localization and sub-cellular distribution of Arg3.1/Arc protein in GFAP positive glia (GFAP-IR) in the DG. Arg3.1/Arc labelling was seen prominently in GFAP-IR glial cell bodies and in large- and medium-sized glial filamentous processes. GFAP-labelled medium-small peri-synaptic glial profiles also displayed Arg3.1/Arc-IR; however, the very thin and distal glial filaments only displayed Arc-IR. Arc-IR was distributed throughout the cytoplasm, often associated with GFAP filaments, and along the plasma membrane of glial processes. Peri-synaptic glial Arg3.1/Arc-IR processes were apposed to pre- and/or post-synaptic profiles at asymmetric axospinous synapses. These data, taken with our earlier study which provided evidence for an increase in astrocytic Arg3.1/Arc-IR after the induction of LTP, suggest a role for glial Arg3.1/Arc in structural and synaptic plasticity which may be critical for the maintenance of cognitive functions.

Show MeSH
Related in: MedlinePlus