Figure 6

Synaptic facilitation by forskolin is not impaired by an ERK inhibitor (U0126). PKA activation by forskolin (5 μM, 15 min) increased transmission at the PB-CeLC synapse in slices from normal animals and induced an NMDA receptor-mediated component in the presence of NBQX (20 μM) and bicuculline (30 μM). U0126 (1 μM, 15 min) had no effect but KT5720 (1 μM, 1 min) inhibited the forskolin-induced facilitation. (A) Monosynaptic EPSCs (average of 8–10 traces) recorded in an individual CeLC neuron held at -60 mV and +20 mV. (B) Time course of drug effects at -60 mV and +20 mV (n = 4). Each symbol shows averaged EPSC amplitudes (mean ± SE) normalized to predrug control values (set to 100%). * P < 0.05, ** P < 0.01 (compared to predrug values), + P < 0.05, ++ P < 0.01, +++ P < 0.001 (compared to forskolin without KT5720; repeated-measures ANOVA with Bonferroni post-tests).