Because previous studies have shown that volatile anesthetics have anticholinergic properties [18], we hypothesized that pretreatment with the acetylcholinesterase inhibitor donepezil, which has been approved by the Food and Drug Administration (FDA) for the treatment of Alzheimer's disease, may prevent isoflurane-induced spatial memory impairment in aged mice. The gene discussed is ACHE; the disease is early-onset autosomal dominant Alzheimer disease.