Figure 2.

Exposure to the novel holeboard in the presence of test-pulse stimulation of CA1 afferents enables STD. SC-CA1 synaptic strength was not significantly altered after 10 min of holeboard exploration in vehicle-treated animals. Vehicle was applied 30 min prior to exposure to the holeboard (signified by arrow). Test pulses delivered during holeboard exploration detected STD at SC-CA1 synapses during the first 5 min of exploration. In the absence of test-pulse stimulation, an STD occurred following spatial exploration. Insets: Analog traces representing SC-CA1 field potentials during 1) baseline, 2) holeboard exploration, and 3) 4 h after holeboard exploration. Calibration: vertical bar, 1 mV; horizontal bar, 3 ms.