In AD model rats, degeneration of midbrain limbic dopamine neurons impairs the function of parvalbumin interneurons (La Barbera et al., 2022), leading to early hippocampal hyperexcitability and epilepsy-like activity (Spoleti et al., 2024), which contrasts with the role of acetylcholine in AD. This evidence concerns the gene PVALB and Alzheimer disease.