Figure 4.

Inhibition of Cdk5 activity in hippocampal CA1 neurons results in reduced LTP- and NMDA-evoked currents. (A–C) Tetanic trains induced LTP in the absence, but not in the presence, of 5 μM roscovitine (20 min preincubation). Representative responses in A and B were recorded before and 40 min after high-frequency stimulation. The data points in C are means ± SEM. (D) The inward current evoked by the local application of NMDA was reduced by roscovitine [compare Right with Left (control)]. (E) Normalized peak currents (I Peak) in the presence of roscovitine (5 μM) compared with those in the absence of roscovitine during the application of NMDA. The responses to NMDA decreased in the presence of roscovitine (n = 6), compared with neurons in the absence of roscovitine (n = 6).