CB1 signaling does not influence evoked glutamatergic responses. A, Ventral root (VR) recording showing the alternation of dorsal root (DR) and VLF stimulation. Ventral root recordings expanded from VLF stimulations before and after an episode of SNA are shown below. B, Plot of the amplitudes of VLF-evoked glutamatergic responses in motoneurons, as measured from the ventral root. The responses modulate in an episode-dependent manner, dropping after an episode (vertical lines) and recovering in the IEI. Application of AM 251 or AM 404 had no effect on these responses. C, Dorsal root-evoked responses are not modulated by SNA, and are unaffected following bath application of AM 251 or AM 404. D, Summary of data showing the applied drugs had no effect on VLF- and dorsal root-evoked responses. Twenty dorsal root-evoked values were averaged per preparation in the presence of the drug (20 min after addition of drug) and normalized to last 20 values before drug. VLF-evoked values from two IEIs in the presence of the drug (20 min after addition of drug) were averaged and normalized to the average value of the responses in the last two IEIs before the drug.