Patients with Alzheimer’s disease (AD) have lower levels of the neuromodulator acetylcholine (ACh) in their brains. Donepezil, an AD drug, increases brain ACh levels and improves AD-associated learning deficits. Now, researchers have identified the intracellular signal cascade through which ACh regulates aversive learning, a major preliminary test for AD drugs. Researchers also found that donepezil activates this signal cascade to regulate aversive learning. The findings indicate the potential of the signaling cascade as drug targets.