Substance P innervation of the rat and cat thalamus. II. Cells of origin in the spinal cord

G. Battaglia, A. Rustioni

Research output: Contribution to journalArticle

Abstract

Evidence in the preceding paper suggests that fibers and terminals immunopositive for substance P (SP) in somatosensory thalamic nuclei are part of the spinothalamic tract (STT). In this paper, more direct evidence on this point is provided by immunocytochemistry for SP on the cervical spinal cord, alone or combined with the retrograde transport of colloidal gold-labeled wheat germ agglutinin conjugated to enzymatically inactive horseradish peroxidase (WGAapoHRP-Au). In cats and rats pretreated with colchicine and/or anterolateral chordotomy (to increase SP content in cell bodies), many small to large cell bodies are SP-immunopositive especially in laminae I and V, but also in more ventral laminae of the upper cervical cord. SP neurons are also present in the dorsolateral funiculus (in the lateral spinal nucleus, LSN, in rats) but not in the lateral cervical nucleus or in the internal basilar nucleus. In both species there is a considerable degree of overlap in the distribution of SP-positive neurons and that of STT neurons. SP immunocytochemistry in rats after WGAapoHRP-Au injection in the somatosensory thalamus reveals SP-positive STT neurons in LSN, in lamina I and in lamina V, and, to a lesser extent, in more ventral laminae. These results demonstrate that SP is a marker and/or neuromediator for some STT neurons. Together with the evidence discussed in the preceding paper, the results also suggest that SP-positive neurons may be involved in the transmission of nociceptive input.

Original languageEnglish
Pages (from-to)473-486
Number of pages14
JournalJournal of Comparative Neurology
Volume315
Issue number4
Publication statusPublished - 1992

    Fingerprint

Keywords

  • ascending spinal pathways
  • dorsal horn neurons
  • somatosensory thalamus
  • spinothalamic tract
  • WGAapoHRP-Au

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this