Pharmacological and null mutation approaches reveal nicotinic receptor diversity

Eur J Pharmacol. 2000 Mar 30;393(1-3):123-35. doi: 10.1016/s0014-2999(00)00052-2.


We have developed an array of assays for nicotinic acetylcholine receptor binding and function. [125I]alpha-Bungarotoxin-, (-)-[3H]nicotine-, and [3H]epibatidine-binding nicotinic acetylcholine receptors were assayed in mouse brain membranes and sections. Nicotinic acetylcholine receptor function was quantified using synaptosomal [3H]dopamine, [3H]gamma-aminobutyric acid ([3H]GABA), and 86Rb(+) efflux techniques. Additionally, the effects of beta2 subunit deletion on each of the measures were assessed. Detailed pharmacological comparison revealed minimally six nicotinic binding subtypes: [125I]alpha-bungarotoxin-binding nicotinic acetylcholine receptors; beta2-subunit-dependent and -independent high-affinity (-)-[3H]nicotine-binding sites; beta2-dependent and -independent cytisine-resistant [3H]epibatidine-binding sites; and a beta2-dependent low-affinity [3H]epibatidine binding site. Comparative pharmacology suggested that [3H]GABA and dihydro-beta-erythroidine (DHbetaE)-sensitive 86Rb(+) efflux are mediated by the same (probably alpha4beta2) nicotinic acetylcholine receptor subtype, while other nicotinic acetylcholine receptor subtypes evoke [3H]dopamine and DHbetaE-resistant 86Rb(+) efflux. In whole-brain preparations, each measure of nicotinic acetylcholine receptor function was beta2 dependent. The majority of beta2-independent [3H]epibatidine binding was located in small, scattered brain nuclei, suggesting that individual nuclei may prove suitable for identification of novel, native nicotinic acetylcholine receptors.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Autoradiography
  • Brain / metabolism*
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology
  • Cell Membrane / metabolism
  • Genetic Variation
  • Genotype
  • Mice
  • Mice, Inbred C57BL
  • Mutation
  • Nicotinic Agonists / pharmacology
  • Pyridines / pharmacology
  • Receptors, Nicotinic / drug effects
  • Receptors, Nicotinic / genetics*
  • Receptors, Nicotinic / metabolism
  • Synaptosomes / metabolism*
  • Tritium


  • Bridged Bicyclo Compounds, Heterocyclic
  • Nicotinic Agonists
  • Pyridines
  • Receptors, Nicotinic
  • Tritium
  • epibatidine