Direct projections from the medial preoptic area to spinally-projecting neurons in Barrington's nucleus: an electron microscope study in the rat

Neurosci Lett. 1999 Aug 27;271(3):175-8. doi: 10.1016/s0304-3940(99)00562-5.


Direct projections from the medial preoptic area (MPO) to the pontine micturition center neurons directly projecting to the lumbosacral spinal cord were revealed electron microscopically in the rat by a double labeling method. Biotinylated dextran amine (BDA) was injected into the MPO and horseradish peroxidase (HRP) was injected into the lumbosacral cord segments. At light microscopic level, BDA-labeled presumptive axon terminals completely overlapped with HRP-labeled neurons in Barrington's nucleus. Electron microscopic observation showed that some BDA-labeled axon terminals made synaptic contacts with dendrites of HRP-labeled neurons in Barrington's nucleus. The present results indicated that the MPO may be involved in the modulation of the pontine micturition reflex in the rat.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biotin / analogs & derivatives
  • Dextrans
  • Fluorescent Dyes
  • Horseradish Peroxidase
  • Microscopy, Immunoelectron
  • Neural Pathways
  • Neurons / ultrastructure
  • Pons / cytology*
  • Preoptic Area / cytology*
  • Presynaptic Terminals / ultrastructure
  • Rats
  • Rats, Wistar
  • Spinal Cord / cytology*
  • Urination


  • Dextrans
  • Fluorescent Dyes
  • biotinylated dextran amine
  • Biotin
  • Horseradish Peroxidase