Final answer:
Alzheimer's disease is characterized by a deficiency in the neurotransmitter acetylcholine, which is a central focus for therapeutic interventions aiming to manage the symptoms of the disease.
Step-by-step explanation:
Alzheimer's disease involves a deficiency in the neurotransmitter acetylcholine. This reduction in acetylcholine activity is often treated with drugs that aim to increase its levels by inhibiting the enzyme that breaks it down in the synaptic cleft. Despite the presence of lesions associated with neurofibrillary tangles and beta-amyloid plaques, the mnemonic dysfunction seen in Alzheimer's is significantly impacted by the decrease in acetylcholine transmission. Cognitive decline associated with Alzheimer's also implicates disrupted excitatory/inhibitory balance due to altered GABAergic and glutamate signaling, though acetylcholine deficiency remains a central therapeutic target.