Nicotine and sensory memory in Alzheimer's disease: An event-related potential study

The auditory mismatch negati\ it (MMN) event-related brain potential (ERP) reflects the storage of information in acoustic sensors memory. Thirteen patients with probable Alzheimer's disease (AD), 6 receiving treatment with the cholinesterase inhibitor (ChEI) tacrine (tetrahydroaminoacridine, THA) and 7 receiving, no treatment. ere administered 2 mg of nicotine polacrilex and placebo, MMNs were recorded with 1- and 3- interstimulus intervals pre- and postplacebo/nicotine administration. In nontreated patients, amplitudes were decreased front pre- to postplacebo recordings hut remained stable in THA-treated patients Comparison of pre- and postnicotine MMNs found amplitude increases with nicotine in nontreated but not THA-treated patients. MMN latencies were shortened by nicotine in both treatment groups. These exploratory findings, suggest that nicotine-improved strength of acoustic sensory memory traces and speed of acoustic sensory discrimination in AD are differentially affected by chronic ChEI treatment. (C) 2001 Elsevier Science (USA).