Gαq/11 mediates cholecystokinin activation of the cationic conductance in rat substantia nigra dopaminergic neurons

Tony Wu, Hung Li Wang*

*Corresponding author for this work

Research output: Contribution to journalJournal Article peer-review

18 Scopus citations

Abstract

Using acutely isolated rat substantia nigra neurons, our previous studies indicated that sulfated cholecystokinin octapeptide (CCK-8) excites substantia nigra dopaminergic neurons by increasing the cationic conductance and that pertussis toxin-insensitive G proteins mediate CCK-8 induction of cationic currents. Gαq and Gα11 are expressed in various tissues, including the brain, and likely to mediate pertussis toxin-insensitive neural signal transductions. In the present study, two different experiments were performed to test the hypothesis that Gαq/11 mediates CCK-8 enhancement of the cationic conductance. First, we investigated the expression of Gαq and Gα11 mRNAs in CCK-8-responsive substantia nigra dopaminergic neurons by combining whole-cell patch-clamp recordings with a single-cell reverse transcriptase-polymerase chain reaction assay. After CCK-8-evoked cationic currents were recorded, cellular RNA was harvested from single neurons and used as a template for the subsequent reverse transcriptase-polymerase chain reaction analysis. Gαq and Gα11 mRNAs were present in all substantia nigra dopaminergic neurons that responded to CCK-8. Substantia nigra dopaminergic neurons were also internally perfused with the antibody raised against the common C-terminus of Gαq and Gα11 during whole-cell recordings. CCK-8 failed to induce cationic currents after dopaminergic neurons were dialyzed with the anti-Gαq/11 antibody. Our studies suggest that CCK-8 activation of the cationic conductance in substantia nigra dopaminergic neurons is transduced by Gαq and/or Gα11.

Original languageEnglish
Pages (from-to)1060-1066
Number of pages7
JournalJournal of Neurochemistry
Volume66
Issue number3
DOIs
StatePublished - 03 1996

Keywords

  • Cationic currents
  • Pertussis toxin-insensitive G proteins
  • Single-cell reverse transcriptase-polymerase chain reaction assay
  • Sulfated cholecystokinin octapeptide
  • Whole-cell patch-clamp recordings

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