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. 1978 Feb;62(2):171–176. doi: 10.1111/j.1476-5381.1978.tb08442.x

The effects of amino acids and antagonists on the isolated hemisected spinal cord of the immature rat.

R H Evans
PMCID: PMC1667817  PMID: 623933

Abstract

1 Records of ventral and dorsal root polarity of the isolated hemisected spinal cord of the 3-9 day old rat showed that respective dose-dependent depolarizations of motoneurones (VR responses) and primary afferent terminals (DR responses) were produced by both acidic and neutral amino acids in the presence of procaine (1 mM) or tetrodotoxin (0.1 micron). 2 Of the four neutral amino acids, gamma-aminobutyrate (GABA), glycine, taurine, and beta-alanine, GABA was the most effective in producing DR responses and glycine the most effective in producing VR responses. Only taurine depressed the electrical activity recorded from ventral roots. 3 The DR responses produced by GABA, beta-alanine and taurine were all antagonized by bicuculline (5 micron) and picrotoxin (5 micron). Bicuculline was more selective than picrotoxin in antagonizing VR responses produced by GABA. 4 Strychnine (1 micron) antagonized VR responses produced by glycine beta-alanine and taurine without affecting responses produced by GABA. DR responses to the neutral amino acids were unaffected by strychnine.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Barker J. L., Nicoll R. A., Padjen A. Studies on convulsants in the isolated frog spinal cord. I. Antagonism of amino acid responses. J Physiol. 1975 Mar;245(3):521–536. doi: 10.1113/jphysiol.1975.sp010859. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Biscoe T. J., Evans R. H., Headley P. M., Martin M. R., Watkins J. C. Structure-activity relations of excitatory amino acids on frog and rat spinal neurones. Br J Pharmacol. 1976 Nov;58(3):373–382. doi: 10.1111/j.1476-5381.1976.tb07714.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Curtis D. R., Hösli L., Johnston G. A., Johnston I. H. The hyperpolarization of spinal motoneurones by glycine and related amino acids. Exp Brain Res. 1968;5(3):235–258. doi: 10.1007/BF00238666. [DOI] [PubMed] [Google Scholar]
  4. Curtis D. R., Johnston G. A. Amino acid transmitters in the mammalian central nervous system. Ergeb Physiol. 1974;69(0):97–188. doi: 10.1007/3-540-06498-2_3. [DOI] [PubMed] [Google Scholar]
  5. Dreifuss J. J., Kelly J. S., Krnjević K. Cortical inhibition and gamma-aminobutyric acid. Exp Brain Res. 1969;9(2):137–154. doi: 10.1007/BF00238327. [DOI] [PubMed] [Google Scholar]
  6. Evans R. H., Francis A. A., Watkins J. C. Bimodal action of glycine on frog spinal motoneurones. Brain Res. 1976 Dec 24;118(3):395–401. doi: 10.1016/0006-8993(76)90307-3. [DOI] [PubMed] [Google Scholar]
  7. Evans R. H., Francis A. A., Watkins J. C. Selective antagonism by Mg2+ of amino acid-induced depolarization of spinal neurones. Experientia. 1977 Apr 15;33(4):489–491. doi: 10.1007/BF01922227. [DOI] [PubMed] [Google Scholar]
  8. Evans R. H., Watkins J. C. Ventral root responses of the hemisected amphibian spinal cord to perfused amino acids in the presence of procaine. Br J Pharmacol. 1975 Dec;55(4):519–526. doi: 10.1111/j.1476-5381.1975.tb07427.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Hill R. G., Simmonds M. A., Straughan D. W. Proceedings: Presynaptic inhibition and the depressant actions of GABA and glycine in the feline cuneate nucleus: changes related to electrographic seizure activity. J Physiol. 1973 Oct;234(2):83P–84P. [PubMed] [Google Scholar]
  10. Konishi S., Otsuka M. Excitatory action of hypothalamic substance P on spinal motoneurones of newborn rats. Nature. 1974 Dec 20;252(5485):734–735. doi: 10.1038/252734a0. [DOI] [PubMed] [Google Scholar]
  11. Nicoll R. A., Padjen A., Barker J. L. Analysis of amino acid responses on frog motoneurones. Neuropharmacology. 1976 Jan;15(1):45–53. doi: 10.1016/0028-3908(76)90096-4. [DOI] [PubMed] [Google Scholar]
  12. Otsuka M., Konishi S. Electrophysiology of mammalian spinal cord in vitro. Nature. 1974 Dec 20;252(5485):733–734. doi: 10.1038/252733a0. [DOI] [PubMed] [Google Scholar]
  13. Otsuka M., Konishi S. Substance P and excitatory transmitter of primary sensory neurons. Cold Spring Harb Symp Quant Biol. 1976;40:135–143. doi: 10.1101/sqb.1976.040.01.015. [DOI] [PubMed] [Google Scholar]
  14. Tebecis A. K., Phillis J. W. The use of convulsants in studying possible functions of amino acids in the toad spinal cord. Comp Biochem Physiol. 1969 Mar;28(3):1303–1315. doi: 10.1016/0010-406x(69)90568-4. [DOI] [PubMed] [Google Scholar]
  15. Young A. B., Snyder S. H. Strychnine binding associated with glycine receptors of the central nervous system. Proc Natl Acad Sci U S A. 1973 Oct;70(10):2832–2836. doi: 10.1073/pnas.70.10.2832. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Zukin S. R., Young A. B., Snyder S. H. Gamma-aminobutyric acid binding to receptor sites in the rat central nervous system. Proc Natl Acad Sci U S A. 1974 Dec;71(12):4802–4807. doi: 10.1073/pnas.71.12.4802. [DOI] [PMC free article] [PubMed] [Google Scholar]

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