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Synaptic activation of presynaptic glutamate transporter currents in nerve terminals.

Publication ,  Journal Article
Palmer, MJ; Taschenberger, H; Hull, C; Tremere, L; von Gersdorff, H
Published in: J Neurosci
June 15, 2003

Glutamate uptake by high-affinity transporters is responsible for limiting the activation of postsynaptic receptors and maintaining low levels of ambient glutamate. The reuptake process generates membrane currents, which can be activated by synaptically released glutamate in glial cells and some postsynaptic neurons. However, less is known about presynaptic transporter currents because the small size of synaptic boutons precludes direct recordings. Here, we have recorded from two giant nerve terminals: bipolar cell synaptic terminals in goldfish retina and the calyx of Held in rat auditory brainstem. Exocytosis was evoked by brief depolarizations and measured as an increase in membrane capacitance. In isolated bipolar cell terminals, exocytosis was associated with an anion (NO3- or Cl-) current. The current peaked 2.8 msec after the start of the depolarization and decayed with a mean time constant of 8.5 msec. It was inhibited by the nontransportable glutamate transporter antagonist sc-threo-beta-benzyloxyaspartate (TBOA) but was insensitive to the GLT1/EAAT2 subtype-selective antagonist dihydrokainate and was affected by extracellular pH buffering. A TBOA-sensitive anion current was also evoked by application of exogenous glutamate to bipolar cell terminals. The large single-channel conductance, derived from noise analysis, and previous immunolocalization studies suggest that synaptically released glutamate activates EAAT5-type transporters in bipolar cell terminals. In contrast, neither exocytosis nor exogenous glutamate evoked a transporter current in the calyx of Held. Glutamate transporter currents with rapid kinetics are therefore identified and characterized in bipolar cell terminals, providing a valuable system for investigating the function and modulation of presynaptic glutamate transporters.

Duke Scholars

Published In

J Neurosci

DOI

EISSN

1529-2401

Publication Date

June 15, 2003

Volume

23

Issue

12

Start / End Page

4831 / 4841

Location

United States

Related Subject Headings

  • Synaptic Transmission
  • Retina
  • Rats, Sprague-Dawley
  • Rats
  • Presynaptic Terminals
  • Photoreceptor Cells
  • Patch-Clamp Techniques
  • Neurology & Neurosurgery
  • In Vitro Techniques
  • Goldfish
 

Citation

APA
Chicago
ICMJE
MLA
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Palmer, M. J., Taschenberger, H., Hull, C., Tremere, L., & von Gersdorff, H. (2003). Synaptic activation of presynaptic glutamate transporter currents in nerve terminals. J Neurosci, 23(12), 4831–4841. https://doi.org/10.1523/JNEUROSCI.23-12-04831.2003
Palmer, Mary J., Holger Taschenberger, Court Hull, Liisa Tremere, and Henrique von Gersdorff. “Synaptic activation of presynaptic glutamate transporter currents in nerve terminals.J Neurosci 23, no. 12 (June 15, 2003): 4831–41. https://doi.org/10.1523/JNEUROSCI.23-12-04831.2003.
Palmer MJ, Taschenberger H, Hull C, Tremere L, von Gersdorff H. Synaptic activation of presynaptic glutamate transporter currents in nerve terminals. J Neurosci. 2003 Jun 15;23(12):4831–41.
Palmer, Mary J., et al. “Synaptic activation of presynaptic glutamate transporter currents in nerve terminals.J Neurosci, vol. 23, no. 12, June 2003, pp. 4831–41. Pubmed, doi:10.1523/JNEUROSCI.23-12-04831.2003.
Palmer MJ, Taschenberger H, Hull C, Tremere L, von Gersdorff H. Synaptic activation of presynaptic glutamate transporter currents in nerve terminals. J Neurosci. 2003 Jun 15;23(12):4831–4841.

Published In

J Neurosci

DOI

EISSN

1529-2401

Publication Date

June 15, 2003

Volume

23

Issue

12

Start / End Page

4831 / 4841

Location

United States

Related Subject Headings

  • Synaptic Transmission
  • Retina
  • Rats, Sprague-Dawley
  • Rats
  • Presynaptic Terminals
  • Photoreceptor Cells
  • Patch-Clamp Techniques
  • Neurology & Neurosurgery
  • In Vitro Techniques
  • Goldfish