123I-5-IA-85380 SPECT imaging of nicotinic receptors in Alzheimer disease and mild cognitive impairment.

Unlabelled: Postmortem binding studies have established that the concentration of alpha(4)beta(2)-nicotinic acetylcholine receptors (alpha(4)beta(2)-nAChR) is reduced in advanced Alzheimer disease (AD). However, the status of this receptor in mild or prodromal AD has remained the subject of controversy.

Methods: We compared alpha(4)beta(2)-nAChR availability in 8 brain regions of living human subjects who had AD and mild cognitive impairment (MCI) with that in age-matched healthy control subjects by using the ligand (123)I-5-IA-85380 ((123)I-5-IA) and SPECT.