Orexinergic innervation of POMC-containing neurons in the rat arcuate nucleus

Neuroreport. 2001 Mar 5;12(3):547-51. doi: 10.1097/00001756-200103050-00023.


A pre-embedding double immunostaining technique was used to study the synaptic relationships between orexin-like immunoreactive axon terminals and preopiomelanocortin (POMC)-like immunoreactive neurons in the rat arcuate nucleus. Most of the synapses were axo-dendritic, while some axo-somatic synapses were also found. Both the axo-somatic and axodendritic synapses were symmetrical. In some cases the presynaptic orexin-like immunoreactive axon terminals contained a few large dense-cored vesicles. The results suggest that the orexinergic axon terminals in the arcuate nucleus may play an important role in the regulation of food intake via synapses through POMC neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arcuate Nucleus of Hypothalamus / chemistry
  • Arcuate Nucleus of Hypothalamus / cytology*
  • Carrier Proteins / analysis*
  • Eating / physiology
  • Intracellular Signaling Peptides and Proteins*
  • Male
  • Microscopy, Immunoelectron
  • Neurons / chemistry*
  • Neurons / ultrastructure
  • Neuropeptides / analysis*
  • Orexins
  • Pro-Opiomelanocortin / analysis*
  • Rats
  • Rats, Wistar
  • Synapses / chemistry
  • Synapses / ultrastructure


  • Carrier Proteins
  • Intracellular Signaling Peptides and Proteins
  • Neuropeptides
  • Orexins
  • Pro-Opiomelanocortin