Propofol improves learning and memory function in aged AD Tg mice. A) Propofol (black circle) does not decrease escape latency as compared to saline (white circle) after the four week treatment (1st four week, 50 mg/kg propofol) in 18 month-old AD Tg mice. B) Propofol (black circle) does not decrease escape latency as compared to saline (white circle) after another four week treatment (2nd four week, 50 mg/kg) in 19 month-old AD Tg mice. C) Propofol (black circle) decreases escape latency as compared to saline (white circle) after another four week treatment (3rd four week, 50 mg/kg propofol) in 20 month-old AD Tg mice. D) Propofol (black circle) decreases escape latency as compared to saline (white circle) after another four week treatment (final four week, 50 mg/kg) in 21 month-old AD Tg mice. AD, Alzheimer's disease, Tg, transgenic. n = 10.