Changes in Nicotinic and Muscarinic Cholinergic Receptors in Alzheimer‐Type Dementia

Abstract

Nicotinic and muscarinic cholinergic receptors were studied in autopsied brains from four histologically normal controls and five histopathologically verified cases of Alzheimer-type dementia (ATD), using ligand binding techniques. Nicotinic and muscarinic cholinergic receptors were assessed by (–)-[³H]nicotine and [³H]quinuclidinyl benzilate ([³H]QNB), respectively. Compared with the controls, (–)-[³H]nicotine binding sites in the ATD brain regions examined were significantly reduced in the putamen and the nucleus basalis of Meynert (NbM). [³H]QNB binding was significantly reduced in the hippocampus and NbM. These findings suggest that there are significant changes of nicotinic and muscarinic cholinergic receptors in selected regions of ATD brains.