NPY and epilepsy: Y2R is involved in the control of food intake and memory retention, mood disorders and epilepsy.[20] Its natural ligand is the 36 residue hormone neuropeptide Y (NPY) that forms an amphipathic C‐terminal α‐helix.[21] Upon binding to Y1R[22] and Y2R,[23] unwinding of the C‐terminal residues was detected allowing the agonist to reach deep into the binding pocket.