Figure 2.

(a) Applying 10 paired pre- and postsynaptic stimulations leads to significant potentiation of the synapse. (b) Intermixing 10 unpaired, postsynaptic stimulations only cancels the potentiation. (c) Applying 10 unpaired stimulations after 10 paired also cancels potentiation. (d) Delaying the unpaired stimulations by 15 or 50 min preserves the potentiation of the 10 paired trials. The presynaptic stimulation is shown as a curve to represent the excitatory postsynaptic potential that arrives in the postsynaptic neuron, the postsynaptic stimulation as a vertical bar to represent an action potential. Adapted from Bauer et al. [17]; epsp, excitatory postsynaptic potential.