Fig. 1.

Cannabinoids prevent the induction of ATP-induced LTP in CA1 region of hippocampus. a ATP-induced long-term potentiation (130.1 ± 3.8%, n = 10). Time course plot represents averaged amplitudes of fEPSPs recorded in CA1 neurons in response to test stimuli delivered to Schaffer collaterals/commissural afferents at 0.05 Hz. Horizontal bar represents application protocol: ATP (10 μM, here and below). Inset: Examples of field fEPSP in control (1) and after LTP induction (2). b fEPSP amplitude declines in the continuous presence of WIN55,212-2 (WIN-2, below), 100nM (solid spheres); WIN-2 disables induction of ATP-induced LTP (n = 4, open circles). c Short application of WIN-2 (100 nM) did not affect fEPSP amplitude. d ATP does not induce LTP after short application of 100 nM of WIN-2