alzheimer'sdisease alzheimerdisease autonomicnervoussystem chemotherapy cholinergic cholinergicagents cholinergicfibers cholinergicreceptors cholinesteraseinhibitors congresses drugeffects drugtherapy nervegrowthfactor neuromuscularjunction neuroregulators neurotransmitteragents parasympathomimetics physiology receptors synaptictransmission therapeuticuse wm220c5471991