Induction of locomotion in spinal tadpoles by excitatory amino acids and their agonists.

Bath application of the excitatory amino acids L-aspartate and/or L-glutamate or their agonists N-methyl-D,L-aspartate and/or kainate elicited swimming movements in spinal tadpoles. Swimming cycles induced by the amino acids were in the frequency range of natural movements, and could be evoked after sectioning all dorsal roots in the exposed spinal segments. Locomotion was only elicited by L-aspartate or L-glutamate at low concentrations when the bath medium was rapidly circulated over the exposed surface of the spinal cord, and was of much shorter duration than the agonist-induced movements. These results indicate some differences between the actions of L-aspartate and L-glutamate and their agonists on the tadpole spinal cord.

[1]  A. C. Taylor,et al.  Stages in the normal development of Rana pipiens larvae , 1946, The Anatomical record.

[2]  J. Parlange,et al.  Water uptake, diameter change, and nonlinear diffusion in tree stems. , 1975, Plant physiology.

[3]  S. Grillner.  Locomotion in vertebrates: central mechanisms and reflex interaction. , 1975, Physiological reviews.

[4]  G. Fagg,et al.  The uptake and release of putative amino acid neurotransmitters , 1979, Neuroscience.

[5]  A. Roberts,et al.  Excitatory amino acid receptors in Xenopus embryo spinal cord and their role in the activation of swimming. , 1984, The Journal of physiology.

[6]  S. Grillner,et al.  The role of putative excitatory amino acid neurotransmitters in the initiation of locomotion in the lamprey spinal cord. II. The effects of amino acid uptake inhibitors , 1985, Brain Research.

[7]  A. McClellan,et al.  Pharmacological activation of locomotor patterns in larval and adult frog spinal cords , 1985, Brain Research.

[8]  S. Grillner,et al.  The role of putative excitatory amino acid neurotransmitters in the initiation of locomotion in the lamprey spinal cord. I. The effects of excitatory amino acid antagonists , 1985, Brain Research.

[9]  A. Roberts,et al.  Inhibitory neurones of a motor pattern generator in Xenopus revealed by antibodies to glycine , 1986, Nature.

[10]  E. Cherubini,et al.  A study of amino acid-activated currents recorded from frog motoneurones in vitro , 1987, Neuroscience Letters.

[11]  N. Kudo,et al.  N-Methyl-d,l-aspartate-induced locomotor activity in a spinal cord-indlimb muscles preparation of the newborn rat studied in vitro , 1987, Neuroscience Letters.

[12]  Michael J. O'Donovan,et al.  The effects of excitatory amino acids and their antagonists on the generation of motor activity in the isolated chick spinal cord. , 1987, Brain research.