Anatomical distribution and ultrastructural organization of the GABAergic system in the rat spinal cord. An immunocytochemical study using anti-GABA antibodies

Neuroscience. 1987 Mar;20(3):1001-9. doi: 10.1016/0306-4522(87)90258-2.


gamma-Aminobutyric acid (GABA)-containing elements have been studied by light and electron microscopy in the rat spinal cord, using immunocytochemistry with anti-GABA antibodies. Light microscopy showed immunoreactive somata localized principally in laminae I-III, and occasionally in the deeper laminae of the dorsal horn and in the ventral horn. Small somata were also observed around the central canal. Punctate GABA-immunoreactive profiles were particularly concentrated in laminae I-III, and moderately abundant in the deeper laminae and in the ventral horn where they were observed surrounding the unlabelled motoneurons. At the ultrastructural level, the punctate profiles corresponded to GABA-containing axonal varicosities or small dendrites. GABA-immunoreactive varicosities were presynaptic to labelled or unlabelled dendrites and cell bodies. Some unlabelled terminals presynaptic to unlabelled dendrites received symmetrical synaptic contacts from GABA-immunoreactive terminals. These results confirm data obtained with L-glutamate decarboxylase immunocytochemistry, and support the role of GABA in pre- and postsynaptic inhibition in the spinal cord, respectively via axoaxonal and axosomatic or axodendritic synapses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies
  • Histocytochemistry
  • Immunoenzyme Techniques
  • Male
  • Microscopy, Electron
  • Rats
  • Rats, Inbred Strains
  • Spinal Cord / analysis*
  • Spinal Cord / ultrastructure
  • Synapses / analysis
  • Synapses / ultrastructure
  • gamma-Aminobutyric Acid / analysis*
  • gamma-Aminobutyric Acid / immunology


  • Antibodies
  • gamma-Aminobutyric Acid