Differential Induction of Long-Term Potentiation in the Horizontal versus Columnar Superficial Connections to Layer II Cells of the Entorhinal Cortex
Figure 7
LTP in the columnar associative (ascending)
pathway of superficial entorhinal cortex. The stimulation electrode was
positioned on the surface of layer III, just deep to the recording electrode. (a) Normalized scaled amplitude of peak
EPSCs evoked by test pulses in a layer II cell is plotted against time. Application
of HFS delivered at time zero led to an immediate and long-lasting increase in the
amplitude of EPSCs. This posttetanic potentiation lasted less than 5 minutes
before it reached a stable and potentiated level. The inset shows two traces reflecting
averaged EPSCs at baseline (pre-HFS) and at 30 minutes post-HFS. (b) Average normalized scaled amplitude
of peak EPSCs across 11 cells. The values at 30 and 50 minutes post-HFS ( and , resp.) were significantly
different from baseline ().
