Figure 9.

Effects of local BAPTA applications in NVsnpr on subthreshold motoneuronal activity. (A) Schematic drawing of the brainstem slice preparation and the experimental conditions used. (B) Raster plots of detected PSPs in six MNs before and after the application of BAPTA in NVsnpr. Traces are aligned on the BAPTA application. (C) Effect of the BAPTA application on the amplitude (left) and frequency (right) of these PSPs. Data are mean ± SEM; *P < 0.05, paired Student’s t-test. (D) Example of a case where spontaneous PSPs recorded in the MN were of greater amplitude after BAPTA application in NVsnpr. (E) Example of a case where BAPTA application in NVsnpr induced rhythmic (right) clusters of PSPs (right inset) in the recorded MN. (F) BAPTA application in the dorsal NVsnpr elicited repetitive depolarizations caused by the summation of spontaneous PSPs (inset) in the recorded motoneuron. The raster plot above the raw trace shows a decrease of the inter-PSP intervals a few seconds before these large summation events. Abbreviations: NVsnpr, trigeminal main sensory nucleus; NVmt, trigeminal motor nucleus; PSPs, post-synaptic potentials.