Distribution of glucagon-like peptide-1 immunoreactivity in the hypothalamic paraventricular and supraoptic nuclei

J Chem Neuroanat. 2008 Dec;36(3-4):144-9. doi: 10.1016/j.jchemneu.2008.07.009. Epub 2008 Aug 19.

Abstract

Glucagon-like peptide-1 (GLP-1) plays a role in modulating neuroendocrine and autonomic function. The hypothalamic paraventricular nucleus (PVN) contains aggregations of GLP-1 fibers and expresses GLP-1 receptors, making it a likely site of action for GLP-1 signaling. The current study was designed to establish domains of GLP-1 action, focusing on axosomatic appositions on different neuroendocrine and autonomic cell populations in the PVN. The data indicate abundant GLP-1-immunoreactive terminal appositions on corticotropin-releasing hormone neurons in the medial parvocellular PVN. GLP-1 positive boutons can also be observed in apposition to oxytocinergic neurons and on retrogradely labeled pre-autonomic neurons projecting to the region of the nucleus of the solitary tract. In contrast, there were very few vasopressinergic neurons with GLP-1 appositions. Overall, the data indicate that the central GLP-1 system preferentially targets neurons in hypophysiotrophic zones of the PVN, consistent with excitatory actions of GLP-1 on adrenocorticotropin release. GLP-1 is also in position to influence oxytocin secretion and control outflow to brainstem cardiovascular relays.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adrenalectomy
  • Animals
  • Arginine Vasopressin / metabolism
  • Corticotropin-Releasing Hormone / metabolism
  • Glucagon-Like Peptide 1 / metabolism*
  • Image Processing, Computer-Assisted
  • Immunohistochemistry
  • Nerve Fibers / metabolism
  • Neurophysins / metabolism
  • Oxytocin / metabolism
  • Paraventricular Hypothalamic Nucleus / cytology
  • Paraventricular Hypothalamic Nucleus / metabolism*
  • Presynaptic Terminals / metabolism
  • Rats
  • Rats, Long-Evans
  • Rats, Sprague-Dawley
  • Supraoptic Nucleus / cytology
  • Supraoptic Nucleus / metabolism*

Substances

  • Neurophysins
  • Arginine Vasopressin
  • Oxytocin
  • Glucagon-Like Peptide 1
  • Corticotropin-Releasing Hormone