Effects of acute nicotine administration on cognitive event-related potentials in tacrine-treated and non-treated patients with Alzheimer's disease.
Earlier studies of cognitive event-related brain potentials (ERPs) reporting diminished amplitudes and delayed latencies of the P300 potential in dementia of the Alzheimer type (DAT), together with independent findings of the P300- and performance-enhancing properties of nicotine in normal adults, stimulated this study to explore the single-dose effects of nicotine on auditory and visual P300s in DAT. Thirteen patients, 6 currently receiving treatment with the cholinesterase inhibitor tacrine (tetrahydroaminoacridine; THA) and the remaining being medication free, were administered 2 mg of nicotine polacrilex under double-blind, randomized, placebo-controlled conditions. Prior to nicotine administration, THA-treated patients exhibited shorter auditory P300 latencies than non-treated patients. Acutely administered nicotine failed to alter auditory P300, but increased the amplitudes of visual P300s in both DAT patient groups. Neither THA treatment nor single-dose nicotine altered behavioural performance in the visual and auditory task paradigms. The results are discussed in relation to nicotinic cholinergic, attentional and cognitive processes in DAT.
Knott
V
V
Department of Psychiatry, University of Ottawa/Royal Ottawa Hospital and Institute of Mental Health Research, Ottawa, Ontario, Canada. vknott@rohcg.on.ca
Mohr
E
E
Mahoney
C
C
Engeland
C
C
Ilivitsky
V
V
D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000188:drug therapy*; D003071:Cognition / Q000187:drug effects*; D004311:Double-Blind Method; D018913:Event-Related Potentials, P300 / Q000187:drug effects*; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D005074:Evoked Potentials, Visual / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000008:administration & dosage* / Q000494:pharmacology*; D018697:Nootropic Agents / Q000627:therapeutic use; D013619:Tacrine / Q000627:therapeutic use
D018697:Nootropic Agents; D013619:Tacrine; D009538:Nicotine