High Availability of the α7-Nicotinic Acetylcholine Receptor in Brains of Individuals with Mild Cognitive Impairment: A Pilot Study Using ¹⁸F-ASEM PET.

Abstract

Emerging evidence supports a hypothesized role for the α7-nicotinic acetylcholine receptor (α7-nAChR) in the pathophysiology of Alzheimer's disease. ¹⁸F-ASEM (3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-6-¹⁸F-fluorodibenzo[b,d]thiophene 5,5-dioxide) is a radioligand for estimating the availability of α7-nAChR in the brain in vivo with PET. <b>Methods:</b> In this cross-sectional study, 14 patients with mild cognitive impairment (MCI), a prodromal stage to dementia, and 17 cognitively intact, elderly controls completed ¹⁸F-ASEM PET. For each participant, binding in each region of interest was estimated using Logan graphical analysis with a metabolite-corrected arterial input function. <b>Results:</b> Higher ¹⁸F-ASEM binding was observed in MCI patients than in controls across all regions, supporting higher availability of α7-nAChR in MCI. ¹⁸F-ASEM binding was not associated with verbal memory in this small MCI sample. <b>Conclusion:</b> These data support use of ¹⁸F-ASEM PET to examine further the relationship between α7-nAChR availability and MCI.