In Vitro Release of Endogenous Amino Acids from Granule Cell‐, Stellate Cell‐, and Climbing Fiber‐Deficient Cerebella

R. S. Flint, M. A. Rea, W. J. McBride

Research output: Contribution to journalArticle

55 Scopus citations

Abstract

The K+-stimulated, Ca2+-dependent release of glutamate, aspartate, γ-aminobutyric acid (GABA), alanine, taurine, and glycine was measured in slices of cerebella obtained from control, and granule cell-, granule cell plus stellate cell-, or climbing fiber-deficient cerebella of the rat. The 55 mM-K+-stimulated release of glutamate and GABA was 10-fold greater in the presence of Ca2+ than in its absence. The stimulated release of aspartate was 4-fold higher when Ca2+ was present in the bathing media, while the value for alanine was twice as high as the amount obtained in the absence of Ca2+. There was no stimulated release of either taurine or glycine from the cerebellar slices. Increasing the Mg2+ concentration to 16 mM inhibited the K+-stimulated, Ca2+-dependent release of glutamate, GABA, aspartate, and alanine 85% or more. The K+-stimulated, Ca2+ dependent release of glutamate, aspartate, and alanine from x-irradiated cerebella deficient in granule cells was reduced to 50-57% of control value. Additional X-irradiation treatment, which further reduced the cerebellar granule cell population and also prevented the acquisition of stellate cells, decreased the release of glutamate by 77%, aspartate by 66%, alanine by 91%, and, in addition, decreased the release of GABA by 55%. The K+-stimulated, Ca2+-dependent release of glutamate, aspartate, GABA, and alanine was not changed in climbing fiber-deficient cerebella obtained from 3-acetylpyridine-treated rats. The data support a transmitter role for GABA and glutamate in the cerebellum, but do not support a similar function for either taurine or glycine. The data also suggest that alanine and aspartate may be coreleased along with glutamate from granule cells.

Original languageEnglish (US)
Pages (from-to)1425-1430
Number of pages6
JournalJournal of Neurochemistry
Volume37
Issue number6
DOIs
StatePublished - Dec 1981

Keywords

  • Aspartate
  • Cerebellum
  • GABA
  • Glutamate
  • Release
  • Taurine.

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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