Targeting brain α7 nicotinic acetylcholine receptors in Alzheimer's disease: rationale and current status

CNS Drugs. 2014 Nov;28(11):975-87. doi: 10.1007/s40263-014-0201-3.

Abstract

Alzheimer's disease (AD) is the most common form of dementia among older persons. Pathognomonic hallmarks of the disease include the development of amyloid senile plaques and deposits of neurofibrillary tangles. These changes occur in the brain long before the clinical manifestations of AD (cognitive impairment in particular) become apparent. Nicotinic acetylcholine receptors (AChRs), particularly the α7 subtype, are highly expressed in brain regions relevant to cognitive and memory functions and involved in the processing of sensory information. There is strong evidence that implicates the participation of AChRs in AD. This review briefly introduces current strategies addressing the pathophysiologic findings (amyloid-β-peptide plaques, neurofibrillary tangles) and then focuses on more recent efforts of pharmacologic intervention in AD, specifically targeted to the α7 AChR. Whereas cholinesterase inhibitors such as donepezil, galantamine, or rivastigmine, together with the non-competitive N-methyl-D-aspartate receptor antagonist memantine are at the forefront of present-day clinical intervention for AD, new insights into AChR molecular pharmacology are bringing other drugs, directed at AChRs, to center stage. Among these are the positive allosteric modulators that selectively target α7 AChRs and are aimed at unleashing the factors that hinder agonist-mediated, α7 AChR channel activation. This calls for more detailed knowledge of the distribution, functional properties, and involvement of AChRs in various signaling cascades-together with the corresponding abnormalities in all these properties-to be able to engineer strategies in drug design and evaluate the therapeutic possibilities of new compounds targeting this class of neurotransmitter receptors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Allosteric Regulation / drug effects*
  • Alzheimer Disease / drug therapy*
  • Alzheimer Disease / metabolism
  • Alzheimer Disease / pathology
  • Amyloid beta-Peptides / metabolism
  • Cholinesterase Inhibitors / administration & dosage
  • Cholinesterase Inhibitors / pharmacology
  • Cholinesterase Inhibitors / therapeutic use*
  • Cognition / drug effects
  • Humans
  • Neurofibrillary Tangles / drug effects
  • Neurofibrillary Tangles / metabolism
  • Neurofibrillary Tangles / pathology
  • Nicotinic Agonists / administration & dosage
  • Nicotinic Agonists / pharmacology
  • Nicotinic Agonists / therapeutic use*
  • alpha7 Nicotinic Acetylcholine Receptor / agonists*

Substances

  • Amyloid beta-Peptides
  • Cholinesterase Inhibitors
  • Nicotinic Agonists
  • alpha7 Nicotinic Acetylcholine Receptor