PMID- 22279011
OWN - NLM
STAT- MEDLINE
DCOM- 20120612
LR  - 20161125
IS  - 1098-1136 (Electronic)
IS  - 0894-1491 (Linking)
VI  - 60
IP  - 4
DP  - 2012 Apr
TI  - Intracellular Na+ concentration influences short-term plasticity of glutamate 
      transporter-mediated currents in neocortical astrocytes.
PG  - 605-14
LID - 10.1002/glia.22294 [doi]
AB  - Fast synaptic transmission requires a rapid clearance of the released 
      neurotransmitter from the extracellular space. Glial glutamate transporters 
      (excitatory amino acid transporters, EAATs) strongly contribute to glutamate 
      removal. In this work, we investigated the paired-pulse plasticity of 
      synaptically activated, glutamate transporter-mediated currents (STCs) in 
      cortical layer 2/3 astrocytes. STCs were elicited by local electrical stimulation 
      in layer 4 in the presence of ionotropic glutamate (AMPA and NMDA), GABAA, and 
      GABAB receptor antagonists. In experiments with low [Na(+)]i (5 mM) intrapipette 
      solution, STCs elicited by paired-pulse stimulation demonstrated paired-pulse 
      facilitation (PPF) at short (<250 ms) interstimulus intervals (ISIs) and 
      paired-pulse depression at longer ISIs. In experiments with close to 
      physiological, high [Na(+)]i (20 mM) intrapipette solution, PPF of STCs at short 
      ISIs was significantly reduced. In addition, the STC kinetics was slowed in the 
      presence of high [Na(+)]i. Exogenous GABA increased astrocytic [Na(+)]i, reduced 
      the mean STC amplitude, decreased PPF at short ISIs, and slowed STC kinetics. All 
      GABA-induced changes were blocked by NO-711 and SNAP-5114, GABA transporter 
      (GATs) antagonists. In experiments with the low intrapipette solution, GAT 
      blockade under control conditions decreased PPF at short ISIs both at room and at 
      near physiological temperatures. Dialysis of single astrocyte with low [Na(+)]i 
      solution increased the amplitude and reduced PPR of evoked field potentials 
      recorded in the vicinity of the astrocyte. We conclude that (1) endogenous GABA 
      via GATs may influence EAAT functioning and (2) astrocytic [Na(+)]i modulates the 
      short-term plasticity of STCs and in turn the efficacy of glutamate removal.
CI  - Copyright (c) 2012 Wiley Periodicals, Inc.
FAU - Unichenko, Petr
AU  - Unichenko P
AD  - Institute of Physiology and Pathophysiology, Universal Medical Center of the 
      Johannes Gutenberg University Mainz, Mainz, Germany.
FAU - Myakhar, Olga
AU  - Myakhar O
FAU - Kirischuk, Sergei
AU  - Kirischuk S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120125
PL  - United States
TA  - Glia
JT  - Glia
JID - 8806785
RN  - 0 (1-(2-(tris(4-methoxyphenyl)methoxy)ethyl)-3-piperidinecarboxylic acid)
RN  - 0 (Amino Acid Transport System X-AG)
RN  - 0 (Anisoles)
RN  - 0 (Benzofurans)
RN  - 0 (Calcium Channel Blockers)
RN  - 0 (Ethers, Cyclic)
RN  - 0 (Excitatory Amino Acid Antagonists)
RN  - 0 (GABA Antagonists)
RN  - 0 (Nipecotic Acids)
RN  - 0 (Oximes)
RN  - 0 (Rhodamines)
RN  - 0 (Sodium Channel Blockers)
RN  - 0 (benzyloxyaspartate)
RN  - 124549-08-2 (sodium-binding benzofuran isophthalate)
RN  - 145645-62-1 (NNC 711)
RN  - 30KYC7MIAI (Aspartic Acid)
RN  - 4368-28-9 (Tetrodotoxin)
RN  - 56-12-2 (gamma-Aminobutyric Acid)
RN  - 9NEZ333N27 (Sodium)
RN  - FX0ES3271V (sulforhodamine 101)
RN  - J6K4F9V3BA (Cadmium Chloride)
SB  - IM
MH  - Action Potentials/drug effects/physiology
MH  - Amino Acid Transport System X-AG/antagonists & inhibitors/*metabolism
MH  - Animals
MH  - Animals, Newborn
MH  - Anisoles/pharmacology
MH  - Aspartic Acid/pharmacology
MH  - Astrocytes/drug effects/*physiology
MH  - Benzofurans/metabolism
MH  - Biophysics
MH  - Cadmium Chloride/pharmacology
MH  - Calcium Channel Blockers/pharmacology
MH  - Electric Stimulation
MH  - Ethers, Cyclic/metabolism
MH  - Excitatory Amino Acid Antagonists/pharmacology
MH  - GABA Antagonists/pharmacology
MH  - In Vitro Techniques
MH  - Intracellular Fluid/drug effects/*metabolism
MH  - Mice
MH  - Mice, Inbred C57BL
MH  - Neocortex/*cytology
MH  - Neuronal Plasticity/drug effects/*physiology
MH  - Nipecotic Acids/pharmacology
MH  - Oximes/pharmacology
MH  - Patch-Clamp Techniques
MH  - Rhodamines/metabolism
MH  - Sodium/*metabolism
MH  - Sodium Channel Blockers/pharmacology
MH  - Synaptic Transmission/drug effects
MH  - Tetrodotoxin/pharmacology
MH  - gamma-Aminobutyric Acid/metabolism/pharmacology
EDAT- 2012/01/27 06:00
MHDA- 2012/06/13 06:00
CRDT- 2012/01/27 06:00
PHST- 2011/03/08 00:00 [received]
PHST- 2011/12/20 00:00 [accepted]
PHST- 2012/01/27 06:00 [entrez]
PHST- 2012/01/27 06:00 [pubmed]
PHST- 2012/06/13 06:00 [medline]
AID - 10.1002/glia.22294 [doi]
PST - ppublish
SO  - Glia. 2012 Apr;60(4):605-14. doi: 10.1002/glia.22294. Epub 2012 Jan 25.