Figure 5.

Presynaptic cytoskeletal changes are required for LPP-LTP. A, Whole-cell, voltage-clamp recordings from CA1 pyramidal cells using electrodes containing Lat-A (400 nM) or veh. Baseline EPSCs were obtained at 3/min for 10 min and then repetitive stimulation applied with membrane potential held at 0 mV. Intracellular Lat-A infusion markedly reduced field CA1 LTP (p < 0.026, n ≥ 6/group). B, Whole-cell recordings show that intracellular Lat-A infusion into DG granule cells had no effect on LTP elicited by LPP stimulation (n = 7/group). C, Field EPSP recordings of LPP responses show that extracellular Lat-A perfusion (500 nm, at horizontal bar) disrupted the stabilization of LPP-LTP (fEPSP recordings; p = 0.0002, n = 8/group).