AMPK activation inhibits L-LTP expression.

<p>A) AMPK activation inhibits LTP induced by HFS. 10 mM 2DG (n = 10) reduces L-LTP to 10% of control (n = 20) (p = 0.034). 5 µM metformin (n = 8) reduces L-LTP to 40% of control (p = 0.028). B) AMPK activation inhibits LTP induced by TBS. 10 mM 2DG reduces L-LTP (p = 0.022, n = 7) to 30% of control (n = 13), 5 µM metformin reduces L-LTP (p = 0.042, n = 12) to 51% of control. 1 mM AICAR reduces L-LTP (p = 0.0025, n = 8) to 11% of control C) 2DG, metformin and AICAR do not have an effect on basic synaptic transmission. Top: input-output relationships for Schaeffer collateral stimulation and fEPSP slope measured in the presence of ACSF (n = 27), 10 mM 2DG (n = 14), 5 µM metformin (n = 17) or 1 mM AICAR (n = 8). Bottom: Paired Pulse Facilitation is not affected by the presence of 10 mM 2DG (n = 11), 5 µM metformin (n = 17) or 1 mM AICAR (n = 8) compared to ACSF alone (n = 14). Results are plotted as the ratio of fEPSP slopes (2^nd stimulus/1^st stimulus X100) as a function of interpulse interval (0–300 msec). *p = 0.0002. A and B) Inset: representative fEPSP traces shown were taken 4 minutes prior and 180 minutes after stimulation. Error bars show s.e.m.