Fig. 4.

Effect of repetitive stimulation with negatively correlated postsynaptic spiking on suprathreshold connections.A, Results from an experiment similar to that described in Figure 3A, except that the synaptic activation was capable of initiating spiking of the postsynaptic neuron. The spike initiated by current pulse injection peaked at ∼10 msec before the onset of each EPSP during repetitive stimulation. Calibration: 100 pA, 10 msec for EPSCs; 40 mV, 10 msec for the EPSP. B, Summary of all experiments similar to that described inA. Data points represent mean ± SEM (n = 3). The mean percentage change in synaptic strength after induction was 31.9 ± 9.3% (±SEM). Significant potentiation was observed (p < 0.05,t test).