Fig. 9.

Sensitivity of bursting to NMDA in a ventral quadrant preparation. A, DC-coupled tracings of bursting activity from left L5 ventral root in a ventral quadrant preparation (for details, see legend to Fig. 8) in strychnine and bicuculline solution (top) to which NMDA (5 μm) is then added (bottom). Right traces are shown with faster time base. Note increase in burst frequency in the presence of NMDA. B, Histograms of cycle period (in sec;left) or burst duration (right) in strychnine + bicuculline solution (open columns) or after addition of NMDA (hatched columns). Data are means of values observed during 5 min periods. **p < 0.0001.