Individual variation in a cholinergic receptor gene modulates attention

Cholinergic influences on attention are well documented and recent evidence indicates that genetic variation in the alpha 4 beta 2 nicotinic receptor affects attentional networks of the brain. Several behavioral and electrophysiological studies have shown that a common polymorphism in the CHRNA4 gene (rs1044396) affects aspects of visual and auditory attentional processing. We examined genetic effects on neuropsychological measures of memory and attention in an adult life-span sample (N = 488). TT homozygotes perform speed and attention tasks more slowly than TC or CC allele carriers, with stronger effects on complex attention tasks in participant 70-79 years of age. There are no parallel effects on memory function. The results are consistent with clinical studies indicating that reduction in nicotinic receptor efficiency affects attention and speed, but not memory. Both normal age-related changes in receptor function and incipient pathology may have contributed to the results. (C) 2009 Elsevier Ireland Ltd. All rights reserved.