Cognitive decline associated with aging is caused by the loss of cholinergic nerve supply to the hippocampus of our brain. Since the hippocampus is the center of learning and memory, a reduction in its synaptic functions leads to cognitive disorders like Alzheimer's disease. To prevent cognitive diseases, it is critical to understand the role of the neurotransmitter acetylcholine in regulating synaptic functions. Scientists now demonstrate the molecular mechanisms underlying these functions.