Underlying alzheimer's disease is a deterioration in neurons that produce:

Deterioration in neurons that produce acetylcholine is an underlying Alzheimer's disease. Acetylcholine is an organic chemical that functions as a neurotransmitter at neuromuscular junctions, at synapses, in the ganglia of the visceral motor system, and at a variety of sites within the central nervous system in the brain and body of many types of animals, including humans. A neurotransmitter is a substance released by synaptic terminals for the purpose of transmitting information from one nerve cell to another.

Dopamine

Alzheimer's Disease is characterized by an impediment in the dopamine regulation function in the brain. Dopamine is a neurotransmitter that is involved in many functions including: memory, mood, cognition and behavior. In Alzheimer's Disease a lack of dopamine production in the brain causes symptoms such as: memory loss and impaired cognitive functioning.