A relationship between substance P receptor and retinal fibers in the rat suprachiasmatic nucleus

Brain Res. 1995 Nov 6;698(1-2):53-61. doi: 10.1016/0006-8993(95)00802-w.

Abstract

The suprachiasmatic nucleus (SCN) in the hypothalamus controls many of the circadian rhythms in mammalian species. In the present study, we investigated the location of substance P receptor (SPR)-containing neurons in the rat SCN, using a specific antibody against SPR, which corresponds to the NK-1 subtype of tachykinin receptors, and also examined the synaptic relationship between SPR-containing neurons and retinal fibers at the ultrastructural level. An SPR-immunoreactive meshwork of labeled somata and dendrites was identified in the SCN. The strongest SPR-immunoreactivity was observed in the dorsal and lateral parts of the SCN. Many labeled somata were identified there and their dendrites protruded ventrally from their somata. A few SPR-immunoreactive somata were observed also in the ventral part of the SCN and within the optic tract. In the SCN of eye-enucleated animals, degenerating retinal fibers were shown to terminate on SPR-immunoreactive dendrites forming asymmetrical axo-dendritic contacts.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Antibody Specificity
  • Immunohistochemistry
  • Microscopy, Electron
  • Nerve Fibers / chemistry*
  • Neurons / chemistry*
  • Rats
  • Rats, Wistar
  • Receptors, Neurokinin-1 / analysis*
  • Retina / chemistry*
  • Retina / ultrastructure
  • Suprachiasmatic Nucleus / chemistry*
  • Suprachiasmatic Nucleus / ultrastructure

Substances

  • Receptors, Neurokinin-1