Figure 5
CDK4 inhibitor impairs mGlu-LTD in the hippocampal CA1 region. (A, B) DHPG-induced LTD. Slices were treated with 100 μM DHPG for 5 min (arrow). The effect is prominent in control slices (n = 11 slices), but impaired in CDK4 inhibitor reincubated slices (n = 12 slices) at both P8-15 and P21-35. The effects of the CDK4 inhibitor at slices from adolescent animals were not as robust as slices from neonatal animals on this form of LTD. (C, D) PP-LFS-induced LTD. The protocol consisted in pairs of stimuli with a 50 ms interstimulus interval, delivered at 1Hz for 15 min (1800 pulses total) in the presence of DL-AP-5 (100 μM). CDK4 inhibitor also inhibited this form of LTD. (E, F) Pooled data show that CDK4 was not required for NMDA receptor-dependent LTD induced by LFS (900 pulses at 1 Hz).