Dynamic properties of unitary EPSPs. A, Examples of unitary connections for corticospinal-to-corticospinal (left), corticostriatal-to-corticostriatal (middle), and corticostriatal-to-corticostriatal (right). SPI, corticospinal; STR, corticostriatal. Examples are plotted individually (top four traces), and together (bottom) with normalization to the first EPSP peak and baseline (upper and lower dashed lines). Horizontal scale bar, 100 ms. B, EPSP decay time constant (τ), for the first EPSP. C, Examples of responses indicating EPSP peaks and troughs (minimum voltage before next EPSP). Bottom, Overlay of traces, normalized to first EPSP. D, Peak amplitudes of the EPSPs in the train, normalized to the amplitude of the first EPSP. Asterisks (*) indicate significant differences between corticospinal-to-corticospinal and corticostriatal-to-corticospinal connections (Tukey's post hoc comparisons, confidence level α = 0.95 with one-way ANOVA). E, Trough amplitudes, normalized to the amplitude of the first EPSP. Asterisk (*) indicates significant differences between corticospinal-to-corticospinal and both other connections (corticostriatal-to-corticospinal and corticostriatal-to-corticostriatal), and crosses (+) indicate significant differences between corticostriatal-to-corticostriatal and corticostriatal-to-corticospinal connections (Tukey post hoc comparisons, confidence level α = 0.95 with one-way ANOVA). F, Trough-subtracted peak EPSP amplitudes, normalized to the amplitude of the first EPSP. Cross (+) indicates significant differences between corticospinal-to-corticospinal and both other connections (corticostriatal-to-corticospinal and corticostriatal-to-corticostriatal), and asterisks (*) indicate significant differences between corticospinal-to-corticospinal and corticostriatal-to-corticostriatal connections (Tukey's post hoc comparisons, confidence level α = 0.95 with one-way ANOVA).