A, H-89 (20 μm in DMSO) or KT5720 (1 μm in DMSO) does not affect baseline recordings (96 ± 5% and 95 ± 2%, respectively, at 55–60 min). B, H-89 inhibits LTD (91 ± 4%versus 65 ± 1% for vehicle control at 70–75 min: P < 0.0001; t test). C, KT5720 inhibits LTD (88 ± 3%versus 67 ± 2% for vehicle control at 70–75 min: P < 0.0001; t test). Open bars: 1 Hz/900 s stimulations; filled bars: drug applications.