Glutamate-induced intracellular acidification of cultured hippocampal neurons demonstrates altered energy metabolism resulting from Ca2+ loads

Jian Wang Guang Jian Wang, R. D. Randall, Stanley A Thayer

Research output: Contribution to journalArticle

142 Scopus citations

Abstract

1. Glutamate-evoked increases in intracellular free H+ concentration ([H+](i)) were recorded from single rat hippocampal neurons grown in primary culture with carboxy SNARF-based dual emission microfluorimetry. The possibility that this acidification resulted from altered energy metabolism was investigated. 2. The response to 10 μM glutamate (ΔpH = 0.41 ± 0.14, mean ± SD) was blocked by the N-methyl-D-aspartate (NMDA) receptor antagonist CGS19755 (10 μM) and required extracellular Ca2+. 3. Substituting the metabolic inhibitor 2-deoxyglucose for glucose in the extracellular buffer prevented glutamate-induced acidification. 4. Ba2+, which carries charge through Ca2+ channels, including the Ca2+ uniporter on the inner mitochondrial membrane, substituted for Ca2+ in mediating glutamate-induced cytoplasmic acidification. 5. Microinjection of ruthenium red, a compound that blocks mitochondrial Ca2+ sequestration, significantly inhibited glutamate-induced acidification. 6. The mitochondrial uncoupler, carbonyl cyanide-p-trifluoromethoxyphenyl-hydrazone (FCCP, 0.1 μM), mimicked and partially occluded the glutamate-induced [H+](i), increase. 7. These findings indicate that glutamate-induced Ca2+ loads are sequestered by mitochondria, uncouple respiration, and produce metabolic acidosis. The glutamate-induced acidification is symptomatic of metabolic stress and may indicate that mitochondria play an important role in glutamate-induced neuronal death.

Original languageEnglish (US)
Pages (from-to)2563-2569
Number of pages7
JournalJournal of neurophysiology
Volume72
Issue number6
DOIs
StatePublished - 1994

Fingerprint Dive into the research topics of 'Glutamate-induced intracellular acidification of cultured hippocampal neurons demonstrates altered energy metabolism resulting from Ca<sup>2+</sup> loads'. Together they form a unique fingerprint.

  • Cite this