The α9 nicotinic acetylcholine receptor shares pharmacological properties with type A γ-aminobutyric acid, glycine, and type 3 serotonin receptors

Carla V. Rothlin, Eleonora Katz, Miguel Verbitsky, A. Belén Elgoyhen

Research output: Contribution to journalArticle


In the present study, we provide evidence that the α9 nicotinic acetylcholine receptor (nAChR) shares pharmacological properties with members of the Cys-loop family of receptors. Thus, the type A γ-aminobutyric acid receptor antagonist bicuculline, the glycinergic antagonist strychnine, and the type 3 serotonin receptor antagonist ICS-205,930 block ACh-evoked currents in α9-injected Xenopus laevis oocytes with the following rank order of potency: strychnine > ICS-205,930 > bicuculline. Block by antagonists was reflected in an increase in the acetylcholine (ACh) EC50 value, with no changes in agonist maximal response or Hill coefficient, which suggests a competitive type of block. Moreover, whereas neither γ-aminobutyric acid nor glycine modified ACh-evoked currents, serotonin blocked responses to ACh in a concentration-dependent manner. The present results suggest that the α9 nAChR must conserve in its primary structure some residues responsible for ligand binding common to other Cys-loop receptors. In addition, it adds further evidence that the α9 nAChR and the cholinergic receptor present at the base of cochlear outer hair cells have similar pharmacological properties.

Original languageEnglish (US)
Pages (from-to)248-254
Number of pages7
JournalMolecular Pharmacology
Issue number2
StatePublished - 1999
Externally publishedYes


ASJC Scopus subject areas

  • Pharmacology

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