Electrical activity was recorded from motoneurons in adult mouse cervical spinal cord (C4-8) slices. Motoneurons showed almost no response to ionophoretic application of N-methyl-D-aspartic acid (NMDA) in both control and Mg(2+)-free media, but very sensitive to kainate (KA) and amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA). Bath perfusion of KA, AMPA or glucose/O(2) free Krebs-Ringer solution, but not bath perfusion of NMDA, caused membrane depolarization within 3 min and beading of the dendrite trees after more than 10 min perfusion. Our results indicate that adult motoneurons have few or no NMDA receptors.
Copyright 2002 Elsevier Science B.V.