Adem, Abdu, Agneta Nordberg, Gösta Bucht and Bengt Winblad: Extraneural cholinergic markers in Alzheimer's and Parkinson's disease. Prog. Neuro-Psychopharmacol. & Biol. Psychiat. 1986, 10 (3–5): 247–257. 1. 1. Muscarinic and nicotinic binding sites were analysed in lymphocytes from patients with Alzheimer's disease, Multi-infarct dementia, Parkinson's disease and age- matched controls. 2. 2. A significant decrease in the number of both muscarinic and nicotinic binding sites was obtained in lymphocytes from Alzheimer patients while in Parkinson patients a significant decrease was found only in the nicotinic binding sites. 3. 3. Using butyrylthiocholine as substrate, no change was observed in cholinesterase activity in plasma from Alzheimer patients, whereas a significant decrease in plasma cholinesterase activity was found in Parkinson patients.