Autoradiographic localization of 5-hydroxytryptamine1A, 5-hydroxytryptamine1B and 5-hydroxytryptamine1C/2 binding sites in the rat spinal cord

Neuroscience. 1993 Jul;55(1):235-52. doi: 10.1016/0306-4522(93)90469-v.


Autoradiographic techniques revealed that 5-hydroxytryptamine1A, 5-hydroxytryptamine1B and 5-hydroxytryptamine1C/2 binding sites are differentially distributed in the spinal cords of adult male rats. In the dorsal horn, 5-hydroxytryptamine1A sites were dense in all laminae; 5-hydroxytryptamine1B sites were more dense in laminae I, III and IV than in lamina II; while 5-hydroxytryptamine1C/2 sites were very sparse. The dorsal commissure gray matter also exhibited very dense 5-hydroxytryptamine1A and 5-hydroxytryptamine1B binding. In the intermediate and central gray matter, all three sites were moderately dense at autonomic levels, with exceptionally dense1C/2 binding restricted to the intermediolateral nucleus at rostral thoracic levels. In the ventral horn, 5-hydroxytryptamine1A and 5-hydroxytryptamine1B sites were very sparse (except for very dense 5-hydroxytryptamine1A sites located in the dorsolateral nucleus of the pudendal nerve), while 5-hydroxytryptamine1C/2 sites were relatively dense in motor nuclei. Surprisingly, 5-hydroxytryptamine1B sites were moderately dense in the dorsal column corticospinal tract. These studies will provide an anatomical perspective for interpretation of the complex role of 5-hydroxytryptamine in regulating spinal cord function.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / metabolism
  • Amphetamines / metabolism
  • Animals
  • Iodocyanopindolol
  • Male
  • Motor Neurons / chemistry
  • Pindolol / analogs & derivatives
  • Pindolol / metabolism
  • Rats
  • Rats, Sprague-Dawley / anatomy & histology
  • Receptors, Serotonin / analysis*
  • Receptors, Serotonin / classification
  • Receptors, Serotonin / metabolism
  • Serotonin / physiology*
  • Spinal Cord / chemistry*
  • Spinal Cord / ultrastructure


  • Amphetamines
  • Receptors, Serotonin
  • Serotonin
  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • Iodocyanopindolol
  • Pindolol
  • 4-iodo-2,5-dimethoxyphenylisopropylamine