Skip to main content
. Author manuscript; available in PMC: 2013 Aug 19.
Published in final edited form as: J Alzheimers Dis. 2009;17(3):681–697. doi: 10.3233/JAD-2009-1071

Figure 3. Caffeine lowers ISF Aβ levels.

Figure 3

(A) Brain ISF Aβx-40 levels were measured by in vivo microdialysis. Prior to treatment with caffeine, ISF Aβ levels fluctuated very little. A low dose (5 mg/kg) and a higher dose (30 mg/kg) of caffeine caused ISF Aβ levels to decrease significantly compared to basal levels. (B) Following a 5 mg/kg dose of caffeine i.p., ISF Aβx-40 levels decreased by 19% compared to basal levels (*p<0.05), while a 30 mg/kg administration decreased Aβ levels by 33% (**p<0.01, n=6 per group). The mean concentration of ISF Aβ represents an average of hours 2–3 after each dose of caffeine when Aβ levels had stabilized. (C) Tg2576 were pre-treated with vehicle or 30 mg/kg caffeine for 3 hours (n=6 per group), followed by administration of 100 nM Compound E, a γ-secretase inhibitor, via reverse microdialysis. In both groups, ISF Aβ levels decreased rapidly when APP cleavage was blocked. (D) The elimination half-life of ISF Aβx-40 was comparable in vehicle-treated and caffeine-treated mice, suggesting that caffeine does not affect ISF Aβ elimination, but likely impacts Aβ production instead.