Figure 4.

In vitro synaptic depression is not dependent on stimulus intensity but is dependent on stimulus duration. A, Magnitude and time course of recovery of in vitro cortical adaptation are independent of afferent stimulus intensity. Synaptic depression during the first minutes post-train does not differ between groups after 50 sec of train stimulation at varying stimulus intensities (n = 6 slices per intensity). B, Varying the duration of train stimulation significantly altered the magnitude of synaptic depression during the first minutes post-train between groups, with 10 sec insufficient to induce depression (n = 6 slices per duration). Asterisks signify significant differences between the 10 sec duration group and all other groups (p < 0.05). Bars indicate duration of trains stimulation.