Cognitive performance and cholinergic transmission: influence of muscarinic and nicotinic receptor blockade

Eur Arch Psychiatry Clin Neurosci. 2010 Nov:260 Suppl 2:S106-10. doi: 10.1007/s00406-010-0160-8. Epub 2010 Oct 20.

Abstract

The cholinergic system is essential in mediating cognitive processes. Although there has been extensive research regarding cholinergic receptor subsystems, the specific contribution of the muscarinic and nicotinic receptor system to cognitive processes still has not been sufficiently explored. In the present study, we examined the selective contribution of muscarinic and nicotinic antagonism to cognitive performance in healthy human subjects. A single-blind, double-dummy, time-elapsed, repeated measures cross-over design was used on 15 healthy males. Subjects completed a neuropsychological test battery assessing a wide range of cognitive domains after 0.4 mg scopolamine (intravenous), 0.2 mg/kg mecamylamine (max. 15 mg; oral) or placebo. Subjects were tested under three conditions: placebo/placebo (PP), scopolamine/placebo (SP) and mecamylamine/placebo (MP). Results show that scopolamine significantly impaired the free recall and recognition performance in the verbal learning test. No other cognitive domain was affected, neither by scopolamine nor by mecamylamine. In line with the existing literature, antagonism of muscarinic receptors resulted in specific cognitive impairments, predominantly memory performance.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Cognition / drug effects*
  • Cross-Over Studies
  • Humans
  • Male
  • Mecamylamine / pharmacology*
  • Muscarinic Antagonists / pharmacology*
  • Neuropsychological Tests
  • Nicotinic Antagonists / pharmacology*
  • Scopolamine / pharmacology*
  • Single-Blind Method
  • Time Factors
  • Young Adult

Substances

  • Muscarinic Antagonists
  • Nicotinic Antagonists
  • Mecamylamine
  • Scopolamine