Fig. 2.

Brief kainate exposure triggers large [Ca²⁺]_i rises in motor neurons. In Fura-2FF-loaded spinal cultures, [Ca²⁺]_i levels were monitored for 5 min before and 25 min after a 5 min exposure to kainate (100 μm + 10 μm MK-801;horizontalbar). Fields selected for imaging contained morphologically identified putative motor neurons (large soma size and extensive dendritic tree); after imaging their identity was verified by immunostaining for SMI-32.Traces represent the means ± SEM of 9 motor neurons and >150 other spinal neurons derived from six experiments.