 |
Previous Article | Next Article 
The Journal of Neuroscience, October 15, 2001, 21(20):7901-7908
Freshly Isolated Hippocampal CA1 Astrocytes Comprise Two
Populations Differing in Glutamate Transporter and AMPA Receptor
Expression
Min
Zhou and
Harold K.
Kimelberg
Center for Neuropharmacology and Neuroscience and Division of
Neurosurgery, Albany Medical College, Albany, New York 12208
We have shown previously that process-bearing GFAP+
astrocytes freshly isolated from rat hippocampus CA1 and CA3 regions
are heterogeneous in ion channel expression and K+
uptake capabilities, such that two distinct populations of astrocytes can be described (Zhou and Kimelberg, 2000). In the present study, we
report that glutamate transporter (GT) currents can only be measured
from one type of these freshly isolated hippocampal CA1 astrocytes
[variably rectifying astrocytes (VRAs)] but were not detectable in
the second type of astrocyte [outwardly rectifying astrocytes
(ORAs)]. The GT currents showed a strict Na+
dependency and high affinity for glutamate (EC50 of 4 ± 1.1 µM). The astrocytes lacking GT currents (ORAs)
showed an AMPA receptor current density (55 pA/pF)
that was 42-fold higher than VRAs (1.3 pA/pF). In contrast, the
GABAA currents were of comparable current density in both
types. The specificity of these differences makes it unlikely that they
are attributable to preparative damage. Therefore, these
findings strongly indicate that, within a single region of the
hippocampus, GFAP+ astrocytes comprise a functionally diverse
population that are qualitatively different in their functional glutamate transporter and quantitatively different in their functional AMPA receptor expression. This heterogeneity implies that GFAP+ astrocytes may participate in or modulate glutamate synaptic
transmission differently.
Key words:
fresh cell isolation; hippocampus; GFAP+ astrocytes; glutamate transporter; AMPA receptor; patch-clamp
Copyright © 2001 Society for Neuroscience 0270-6474/01/21207901-08$05.00/0
This article has been cited by other articles:

|
 |

|
 |
 
Y. Li, B. Krupa, J.-S. Kang, V. Y. Bolshakov, and G. Liu
Glycine Site of NMDA Receptor Serves as a Spatiotemporal Detector of Synaptic Activity Patterns
J Neurophysiol,
July 1, 2009;
102(1):
578 - 589.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
G. Seifert, K. Huttmann, D. K. Binder, C. Hartmann, A. Wyczynski, C. Neusch, and C. Steinhauser
Analysis of Astroglial K+ Channel Expression in the Developing Hippocampus Reveals a Predominant Role of the Kir4.1 Subunit
J. Neurosci.,
June 10, 2009;
29(23):
7474 - 7488.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. W. Nestor, L.-P. Mok, M. E. Tulapurkar, and S. M. Thompson
Plasticity of Neuron-Glial Interactions Mediated by Astrocytic EphARs
J. Neurosci.,
November 21, 2007;
27(47):
12817 - 12828.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Zhou, G. P. Schools, and H. K. Kimelberg
Development of GLAST(+) Astrocytes and NG2(+) Glia in Rat Hippocampus CA1: Mature Astrocytes Are Electrophysiologically Passive
J Neurophysiol,
January 1, 2006;
95(1):
134 - 143.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
X. Chen, L. Wang, Y. Zhou, L.-H. Zheng, and Z. Zhou
"Kiss-and-Run" Glutamate Secretion in Cultured and Freshly Isolated Rat Hippocampal Astrocytes
J. Neurosci.,
October 5, 2005;
25(40):
9236 - 9243.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Jabs, T. Pivneva, K. Huttmann, A. Wyczynski, C. Nolte, H. Kettenmann, and C. Steinhauser
Synaptic transmission onto hippocampal glial cells with hGFAP promoter activity
J. Cell Sci.,
August 15, 2005;
118(16):
3791 - 3803.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Q. Zhang, T. Pangrsic, M. Kreft, M. Krzan, N. Li, J.-Y. Sul, M. Halassa, E. Van Bockstaele, R. Zorec, and P. G. Haydon
Fusion-related Release of Glutamate from Astrocytes
J. Biol. Chem.,
March 26, 2004;
279(13):
12724 - 12733.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. Grass, P. G. Pawlowski, J. Hirrlinger, N. Papadopoulos, D. W. Richter, F. Kirchhoff, and S. Hulsmann
Diversity of Functional Astroglial Properties in the Respiratory Network
J. Neurosci.,
February 11, 2004;
24(6):
1358 - 1365.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. J. Todd, C. A. B. Slatter, and D. W. Ali
Activation of Ionotropic Glutamate Receptors on Peripheral Axons of Primary Motoneurons Mediates Transmitter Release at the Zebrafish NMJ
J Neurophysiol,
February 1, 2004;
91(2):
828 - 840.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Matthias, F. Kirchhoff, G. Seifert, K. Huttmann, M. Matyash, H. Kettenmann, and C. Steinhauser
Segregated Expression of AMPA-Type Glutamate Receptors and Glutamate Transporters Defines Distinct Astrocyte Populations in the Mouse Hippocampus
J. Neurosci.,
March 1, 2003;
23(5):
1750 - 1758.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Stegmuller, H. Werner, K.-A. Nave, and J. Trotter
The Proteoglycan NG2 Is Complexed with alpha -Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid (AMPA) Receptors by the PDZ Glutamate Receptor Interaction Protein (GRIP) in Glial Progenitor Cells. IMPLICATIONS FOR GLIAL-NEURONAL SIGNALING
J. Biol. Chem.,
January 31, 2003;
278(6):
3590 - 3598.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|

|