Selective expression of Narp, a secreted neuronal pentraxin, in orexin neurons

J Neurochem. 2002 Sep;82(6):1561-5. doi: 10.1046/j.1471-4159.2002.01141.x.


Recent studies have provided compelling evidence demonstrating that orexin (also known as hypocretin) neurons play a central role in the pathophysiology of narcolepsy. However, targeted deletion of orexin does not fully mimic the functional deficits induced by selective ablation of these neurons; implying that other secreted signaling molecules expressed in these neurons mediate key aspects of their function. In this study, we demonstrate that orexin neurons display robust expression of neuronal activity-regulated pentraxin (Narp), a secreted neuronal pentraxin, implicated in regulating clustering of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors. Furthermore, we have found that hypothalamic melanin-concentrating hormone (MCH) neurons, which form a peptidergic pathway thought to oppose the effects of the orexin system, express another neuronal pentraxin, NP1. Thus, these findings suggest that these pathways utilize neuronal pentraxins, in addition to neuropeptides, as synaptic signaling molecules.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • C-Reactive Protein / biosynthesis*
  • Carrier Proteins / biosynthesis*
  • Hypothalamic Hormones / biosynthesis
  • Hypothalamus / cytology
  • Hypothalamus / metabolism
  • Immunohistochemistry
  • In Situ Hybridization
  • Intracellular Signaling Peptides and Proteins*
  • Male
  • Melanins / biosynthesis
  • Nerve Tissue Proteins / biosynthesis*
  • Neurons / cytology
  • Neurons / metabolism*
  • Neuropeptides / biosynthesis*
  • Orexins
  • Pituitary Hormones / biosynthesis
  • Rats
  • Rats, Sprague-Dawley


  • Carrier Proteins
  • Hypothalamic Hormones
  • Intracellular Signaling Peptides and Proteins
  • Melanins
  • Nerve Tissue Proteins
  • Neuropeptides
  • Orexins
  • Pituitary Hormones
  • neuronal pentraxin
  • melanin-concentrating hormone
  • C-Reactive Protein