BU224 hydrochloride is a selective and high affinity imidazoline I 2 receptor ligand, with a K i of 2.1 nM. BU224 hydrochloride is sometimes used as an I 2 receptor antagonist. BU224 hydrochloride exerts neuroprotective effects, with anti-inflammatory and anti-apoptotic properties. BU224 hydrochloride improves memory in 5XFAD mice, enlarging dendritic spines and reducing Aβ-induced changes in NMDARs. BU224 hydrochloride can be used for Alzheimer's disease research.