Extracellular Glutamate in the Nucleus Accumbens Is Nanomolar in Both Synaptic and Non-synaptic Compartments

Delia N. Chiu, Craig Jahr

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

In the CNS, glutamate is both phasically and tonically released into the extracellular space and must be removed by excitatory amino acid transporters (EAATs) to prevent excitotoxic accumulation. There remains uncertainty, however, regarding the functional steady-state concentration, with estimates ranging from tens of nanomolar to tens of micromolar. Efforts to reconcile these disparate values have led to a hypothesis that the extracellular space comprises distinct compartments in which basal glutamate concentrations are maintained independently. We used electrophysiology and two-photon Ca2+ imaging to test this hypothesis in the nucleus accumbens (NAc), where it has been proposed that micromolar extracellular glutamate is necessary for normal function. We found that the average concentration of synaptic glutamate is nanomolar, in agreement with previous electrophysiological estimates. Furthermore, this held true when glutamate uptake was inhibited, indicating that extracellular glutamate is not compartmentalized by EAATs.

Original languageEnglish (US)
Pages (from-to)2576-2583
Number of pages8
JournalCell Reports
Volume18
Issue number11
DOIs
StatePublished - Mar 14 2017

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Nucleus Accumbens
Glutamic Acid
Amino Acid Transport Systems
Excitatory Amino Acids
Extracellular Space
Electrophysiology
Photons
Uncertainty
Imaging techniques

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Extracellular Glutamate in the Nucleus Accumbens Is Nanomolar in Both Synaptic and Non-synaptic Compartments. / Chiu, Delia N.; Jahr, Craig.

In: Cell Reports, Vol. 18, No. 11, 14.03.2017, p. 2576-2583.

Research output: Contribution to journalArticle

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