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Ionotropic glutamate receptor GluR1 in the visual cortex of hamster: distribution and co-localization with calcium-binding proteins and GABA.

Ye EA, Kim TJ, Choi JS, Jin MJ, Jeon YK, Kim MS, Jeon CJ - Acta Histochem Cytochem (2006)

Bottom Line: We compared this labeling to that for calbindin D28K, parvalbumin, and GABA.The highest density of GluR1-IR neurons was found in layers II/III.The present study elucidates the neurochemical structure of GluR1, a useful clue in understanding the differential vulnerability of GluR1-containing neurons with regard to calcium-dependent excitotoxic mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, 702-701, Korea.

ABSTRACT
The subunit composition of the AMPA receptor is critical to its function. AMPA receptors that display very low calcium permeability include the GluR2 subunit, while AMPA receptors that contain other subunits, such as GluR1, display high calcium permeability. We have studied the distribution and morphology of neurons containing GluR1 in the hamster visual cortex with antibody immunocytochemistry. We compared this labeling to that for calbindin D28K, parvalbumin, and GABA. Anti-GluR1-immunoreactive (IR) neurons were located in all layers. The highest density of GluR1-IR neurons was found in layers II/III. The labeled neurons were non-pyramidal neurons, but were varied in morphology. The majority of the labeled neurons were round or oval cells. However, stellate, vertical fusiform, pyriform, and horizontal neurons were also labeled with the anti-GluR1 antibody. Two-color immunofluorescence revealed that many of the GluR1-IR neurons in the hamster visual cortex were double-labeled with either calbindin D28K (31.50%), or parvalbumin (22.91%), or GABA (63.89%). These results indicate that neurons in the hamster visual cortex express GluR1 differently according to different layers and selective cell types, and that many of the GluR1-IR neurons are limited to neurons that express calbindin D28K, parvalbumin, or GABA. The present study elucidates the neurochemical structure of GluR1, a useful clue in understanding the differential vulnerability of GluR1-containing neurons with regard to calcium-dependent excitotoxic mechanisms.

No MeSH data available.


Related in: MedlinePlus

High power differential interference contrast (DIC) photomicrographs of some GluR1-IR neurons in the hamster visual cortex. (A, B arrow) Multipolar round or oval neurons in cortical layers II/III. The large majority of anti-GluR1-IR neurons were round or oval cells with many dendrites coursing in all directions. (B arrowhead, D) Multipolar stellate neurons. Stellate neurons had polygonally-shaped cell bodies with numerous dendrites coursing in all directions. (B asterisk, C) Vertical fusiform neurons with its longitudinal axis perpendicular to the pial surface. (E) Pyriform neuron with a thick primary dendrite oriented toward the pial surface. This ascending process had many small branches, forming a dendritic bouquet. (F) A horizontal neuron with a horizontal fusiform cell body with horizontally oriented processes. Bar=20 µm.
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Figure 3: High power differential interference contrast (DIC) photomicrographs of some GluR1-IR neurons in the hamster visual cortex. (A, B arrow) Multipolar round or oval neurons in cortical layers II/III. The large majority of anti-GluR1-IR neurons were round or oval cells with many dendrites coursing in all directions. (B arrowhead, D) Multipolar stellate neurons. Stellate neurons had polygonally-shaped cell bodies with numerous dendrites coursing in all directions. (B asterisk, C) Vertical fusiform neurons with its longitudinal axis perpendicular to the pial surface. (E) Pyriform neuron with a thick primary dendrite oriented toward the pial surface. This ascending process had many small branches, forming a dendritic bouquet. (F) A horizontal neuron with a horizontal fusiform cell body with horizontally oriented processes. Bar=20 µm.

Mentions: In the hamster visual cortex, the majority of the GluR1-IR cells consisted of round or oval cells. Figures 3A and 3B (arrow) show representative multipolar round or oval cells. The round or oval cells were located in all layers. Figure 3B (arrowhead) and 3D show multipolar stellate neurons. Stellate cells had polygonally-shaped cell bodies with numerous dendrites coursing in all directions. The stellate cells were located in all layers except in layer I. Vertical fusiform cells (Fig. 3C and asterisk in 3B) with a thick, proximal dendritic stump directed towards the pial surface were also found. Vertical fusiform cells were predominantly located in layer II/III. Fig. 3E shows a pyriform neuron. Pyriform neurons had a small, pear-shaped cell body with a thick proximal dendrite directed toward the pial surface. The ascending process had many small branches, which formed a dendritic bouquet. The pyriform cells were predominantly located in layer II/III. Horizontal cells (Fig. 3F), with horizontally-oriented small, fusiform cell bodies and horizontally-oriented processes, also contained GluR1. The horizontal cells were predominantly located in layer I. Quantitatively, 73.54% (S.D. 6.71) of anti-GluR1 labeled neurons were round or oval, 15.55% (S.D. 7.21) were vertical fusiform, 7.52% (S.D. 1.95) were stellate, 2.10% (S.D. 0.88) were pyriform, and 1.29% (S.D. 1.02) was horizontal neurons. In the present study, we could not identify any GluR1-IR pyramidal cells.


Ionotropic glutamate receptor GluR1 in the visual cortex of hamster: distribution and co-localization with calcium-binding proteins and GABA.

Ye EA, Kim TJ, Choi JS, Jin MJ, Jeon YK, Kim MS, Jeon CJ - Acta Histochem Cytochem (2006)

High power differential interference contrast (DIC) photomicrographs of some GluR1-IR neurons in the hamster visual cortex. (A, B arrow) Multipolar round or oval neurons in cortical layers II/III. The large majority of anti-GluR1-IR neurons were round or oval cells with many dendrites coursing in all directions. (B arrowhead, D) Multipolar stellate neurons. Stellate neurons had polygonally-shaped cell bodies with numerous dendrites coursing in all directions. (B asterisk, C) Vertical fusiform neurons with its longitudinal axis perpendicular to the pial surface. (E) Pyriform neuron with a thick primary dendrite oriented toward the pial surface. This ascending process had many small branches, forming a dendritic bouquet. (F) A horizontal neuron with a horizontal fusiform cell body with horizontally oriented processes. Bar=20 µm.
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Related In: Results  -  Collection

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Figure 3: High power differential interference contrast (DIC) photomicrographs of some GluR1-IR neurons in the hamster visual cortex. (A, B arrow) Multipolar round or oval neurons in cortical layers II/III. The large majority of anti-GluR1-IR neurons were round or oval cells with many dendrites coursing in all directions. (B arrowhead, D) Multipolar stellate neurons. Stellate neurons had polygonally-shaped cell bodies with numerous dendrites coursing in all directions. (B asterisk, C) Vertical fusiform neurons with its longitudinal axis perpendicular to the pial surface. (E) Pyriform neuron with a thick primary dendrite oriented toward the pial surface. This ascending process had many small branches, forming a dendritic bouquet. (F) A horizontal neuron with a horizontal fusiform cell body with horizontally oriented processes. Bar=20 µm.
Mentions: In the hamster visual cortex, the majority of the GluR1-IR cells consisted of round or oval cells. Figures 3A and 3B (arrow) show representative multipolar round or oval cells. The round or oval cells were located in all layers. Figure 3B (arrowhead) and 3D show multipolar stellate neurons. Stellate cells had polygonally-shaped cell bodies with numerous dendrites coursing in all directions. The stellate cells were located in all layers except in layer I. Vertical fusiform cells (Fig. 3C and asterisk in 3B) with a thick, proximal dendritic stump directed towards the pial surface were also found. Vertical fusiform cells were predominantly located in layer II/III. Fig. 3E shows a pyriform neuron. Pyriform neurons had a small, pear-shaped cell body with a thick proximal dendrite directed toward the pial surface. The ascending process had many small branches, which formed a dendritic bouquet. The pyriform cells were predominantly located in layer II/III. Horizontal cells (Fig. 3F), with horizontally-oriented small, fusiform cell bodies and horizontally-oriented processes, also contained GluR1. The horizontal cells were predominantly located in layer I. Quantitatively, 73.54% (S.D. 6.71) of anti-GluR1 labeled neurons were round or oval, 15.55% (S.D. 7.21) were vertical fusiform, 7.52% (S.D. 1.95) were stellate, 2.10% (S.D. 0.88) were pyriform, and 1.29% (S.D. 1.02) was horizontal neurons. In the present study, we could not identify any GluR1-IR pyramidal cells.

Bottom Line: We compared this labeling to that for calbindin D28K, parvalbumin, and GABA.The highest density of GluR1-IR neurons was found in layers II/III.The present study elucidates the neurochemical structure of GluR1, a useful clue in understanding the differential vulnerability of GluR1-containing neurons with regard to calcium-dependent excitotoxic mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, College of Natural Sciences, Kyungpook National University, Daegu, 702-701, Korea.

ABSTRACT
The subunit composition of the AMPA receptor is critical to its function. AMPA receptors that display very low calcium permeability include the GluR2 subunit, while AMPA receptors that contain other subunits, such as GluR1, display high calcium permeability. We have studied the distribution and morphology of neurons containing GluR1 in the hamster visual cortex with antibody immunocytochemistry. We compared this labeling to that for calbindin D28K, parvalbumin, and GABA. Anti-GluR1-immunoreactive (IR) neurons were located in all layers. The highest density of GluR1-IR neurons was found in layers II/III. The labeled neurons were non-pyramidal neurons, but were varied in morphology. The majority of the labeled neurons were round or oval cells. However, stellate, vertical fusiform, pyriform, and horizontal neurons were also labeled with the anti-GluR1 antibody. Two-color immunofluorescence revealed that many of the GluR1-IR neurons in the hamster visual cortex were double-labeled with either calbindin D28K (31.50%), or parvalbumin (22.91%), or GABA (63.89%). These results indicate that neurons in the hamster visual cortex express GluR1 differently according to different layers and selective cell types, and that many of the GluR1-IR neurons are limited to neurons that express calbindin D28K, parvalbumin, or GABA. The present study elucidates the neurochemical structure of GluR1, a useful clue in understanding the differential vulnerability of GluR1-containing neurons with regard to calcium-dependent excitotoxic mechanisms.

No MeSH data available.


Related in: MedlinePlus