P-Rex is required for a late phase of stimulus-evoked cerebellar LTP.

A) LTP induced by stimulation of parallel fibres at 1 Hz for 5 min in WT mice. Data are mean normalized amplitude (upper panel) and normalized paired pulse ratio (lower panel) ± s.e.m. for 9 cells. B) LTP induced by stimulation of parallel fibres at 1 Hz for 5 min in P-Rex dKO mice is not sustained. Data are mean normalized amplitude (upper panel) and normalized paired pulse ratio (lower panel) ± s.e.m. for 9 cells. Single sample t test was used to test for a significant increase in mean amplitude of five consecutive pulses at 10 min and 30 min post 1 Hz tetanus; p values were as indicated. Traces show average of 5 consecutive EPSCs evoked by paired pulse stimulation (50 ms interval, at arrows) before (left trace), 10 min after (middle trace) and 30 min after (right trace) 1 Hz stimulation, from a representative cell. Grey traces reproduce EPSC before 1 Hz for comparison.