Alpha7 nicotinic acetylcholine receptor-specific agonist DMXBA (GTS-21) attenuates Aβ accumulation through suppression of neuronal γ-secretase activity and promotion of microglial amyloid-β phagocytosis and ameliorates cognitive impairment in a mouse model of Alzheimer's disease.

We previously demonstrated that stimulation of nicotinic acetylcholine receptors (nAChRs) increases amyloid-β (Aβ) phagocytosis in rat microglia and is closely associated with the decrease of brain Aβ and amelioration of memory dysfunction in a transgenic mouse model of Alzheimer's disease (AD). Here, we examined the subtypes of nAChRs involved in these beneficial effects. In primary cultures of rat microglia, the α7 nAChR selective agonist 3-[(2,4-dimethoxy)benzylidene]-anabaseine dihydrochloride (DMXBA) promoted Aβ and fluorescent latex bead phagocytosis, whereas selective α7 nAChR antagonists suppressed the enhanced Aβ phagocytosis.