Galantamine-induced improvements in cognitive function are not related to alterations in alpha(4)beta (2) nicotinic receptors in early Alzheimer's disease as measured in vivo by 2-[18F]fluoro-A-85380 PET
| Autor: | Pradeep J. Nathan, Catherine L Smith, Gregory Raymond Savage, J Welch, Victor L. Villemagne, Michael Woodward, Christopher C. Rowe, Julia R. Ellis, Kenneth Young, Keith Wesnes, T. Saunder, Rachel S. Mulligan |
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| Rok vydání: | 2008 |
| Předmět: |
Male
Fluorine Radioisotopes Pyridines Neuropsychological Tests Receptors Nicotinic Verbal learning Cognition In vivo Alzheimer Disease medicine Galantamine Image Processing Computer-Assisted Reaction Time Humans Nootropic Agents Cholinesterase Aged Pharmacology biology business.industry medicine.disease Magnetic Resonance Imaging Nicotinic acetylcholine receptor Nicotinic agonist Positron-Emission Tomography Space Perception biology.protein Azetidines Female sense organs Alzheimer's disease Radiopharmaceuticals business Arousal Neuroscience Psychomotor Performance medicine.drug |
| Zdroj: | Psychopharmacology. 202(1-3) |
| ISSN: | 1432-2072 |
| Popis: | The nicotinic acetylcholine receptor (nAChR) system plays a regulatory role in a number of cognitive processes. Cholinesterase inhibitors (i.e., galantamine) that potentiate cholinergic neurotransmission improve cognitive function in Alzheimer's disease (AD); however, the relationship between these effects and associated changes in nAChRs are yet to be established in vivo.2-[18F]Fluoro-A-85380 (2-FA) binds to nAChRs and with positron emission tomography (PET) imaging provides a composite measure of receptor density and ligand affinity. This study aimed to: (1) quantify nAChRs in vivo in 15 drug-naïve patients with mild AD before and after chronic treatment with galantamine, using 2-FA and PET, and (2) examine the relationship between treatment-induced changes in nAChRs and improvements in cognitive function. Participants were nonsmokers and underwent extensive cognitive testing and a PET scan after injection of approximately 200 MBq of 2-FA on two occasions (before and after 12 weeks, galantamine treatment). A 3-day washout period preceded the second scan. Brain regional 2-FA binding was assessed through a simplified estimation of distribution volume (DV(S)).Performance on global measures of cognition significantly improved following galantamine treatment (p0.05). This improvement extended to specific cognitive measures of language and verbal learning. No significant differences in nAChR DV(S) before and after galantamine treatment were found. The treatment-induced improvement in cognition was not correlated with regional or global nAChR DV(S), suggesting that changes in nAChRs may not be responsible for the improvements in cognition following galantamine in patients with mild AD. |
| Databáze: | OpenAIRE |
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