Sulphorhodamine‐labelled cells in the neonatal rat spinal cord following chemically induced locomotor activity in vitro.
- 15 July 1994
- journal article
- Published by Wiley in The Journal of Physiology
- Vol. 478 (2), 265-273
- https://doi.org/10.1113/jphysiol.1994.sp020248
Abstract
1. Sulphorhodamine 101, a fluorescent dye and newly identified activity marker, was used to localize potential spinal locomotor networks in the neonatal rat spinal cord. 2. Preparations of the spinal cord with one entire hindlimb attached or the spinal cord in isolation were kept in vitro. Spinal locomotor activity was maintained chemically with NMDA (5-7.5 microM), in combination with 5-HT (7.5-20 microM), for 4-4.5 h in the presence of 0.0001-0.0005% sulphorhodamine 101. Matched non-locomoting controls were exposed to the dye in the absence of transmitters for a comparable time. Transverse sections of the lumbar spinal cord (L1-L6) were screened for rhodamine emission using an epifluorescence microscope. 3. In hindlimb-attached locomoting preparations with intact dorsal roots, labelled cells were found on the leg side in the dorsal horn (mainly laminae II-IV), in the intermediate grey (lamina VI-VII) and around the central canal (lamina X). Dorsal rhizotomy was performed on the leg side, to prevent synaptic activity due to afferent inflow. This largely reduced the number of labelled cells in the dorsal horn and in the lateral part of the intermediate grey matter. A further reduction of labelling in these areas was seen after complete isolation of the cord or when compared to the legless side, with the majority of labelled cells persisting in a bilateral cluster close to the central canal and in the medial intermediate grey. Few labelled cells were observed in non-locomoting preparations. The intensity of motoneuronal labelling was variable.(ABSTRACT TRUNCATED AT 250 WORDS)Keywords
This publication has 17 references indexed in Scilit:
- Induction of fos expression by activity in the spinal rhythm generator for scratchingBrain Research, 1992
- Development of spinal motor networks in the chick embryoJournal of Experimental Zoology, 1992
- Optical Analysis of Synaptic Vesicle Recycling at the Frog Neuromuscular JunctionScience, 1992
- Respiratory pattern generation in mammals: in vitro en bloc analysesCurrent Opinion in Neurobiology, 1991
- The neural network underlying locomotion in lamprey-synaptic and cellular mechanismsNeuron, 1991
- Modulation of Neural Networks for BehaviorAnnual Review of Neuroscience, 1991
- locomotor activity in a spinal cord-indlimb muscles preparation of the newborn rat studied in vitroNeuroscience Letters, 1987
- Multiple innervation of tonic endplates revealed by activity-dependent uptake of fluorescent probesNature, 1985
- The cytoarchitectonic organization of the spinal cord in the rat. I. The lower thoracic and lumbosacral cordJournal of Comparative Neurology, 1984
- Neural Basis of Rhythmic Behavior in AnimalsScience, 1980