Release of Amino Acids from the Spinal Cord in Vitro and in Vivo

  • Robert W. P. Cutler
Part of the Advances in Experimental Medicine and Biology book series (AEMB)


In the last decade, considerable evidence has supported the initial suggestion by Aprison and Werman2 that glycine is a likely inhibitory transmitter in the mammalian spinal cord. The concentration of glycine becomes progressively higher in more caudal areas of the nervous system and it is particularly high, on the order of 5 µmoles/gram, in regions of spinal cord known to contain inhibitory interneurons. The concentration falls after partial spinal cord ischemia in a manner proportional to the loss of interneurons. 12 The action of glycine is antagonized by strychnine, which is known to block postsynaptic inhibitory mechanisms.5 There is reason to believe that other amino acids may have roles as neurotransmitters in the spinal cord, based on less complete evidence than that for glycine. For example, GABA has been proposed as a presynaptic inhibitory transmitter at primary afferent terminals. It is found in high concentrations in the dorsal horn, and local ischemia of this region leads to a marked fall in concentration.23 Deafferentation of the spinal cord by dorsal root section leads to a reduction in glutamic acid decarboxylase activity in the dorsal lateral region of cord, together with a fall in GABA content and a reduction of [3H] GABA uptake.14


Spinal Cord Sciatic Nerve Label Amino Acid Spinal Cord Slice Amino Acid Release 
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Copyright information

© Plenum Press, New York 1976

Authors and Affiliations

  • Robert W. P. Cutler
    • 1
  1. 1.Department of NeurologyStanford University Medical CenterStanfordUSA

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