Amygdaloid axons innervate melanin-concentrating hormone- and orexin-containing neurons in the mouse lateral hypothalamus

Brain Res. 2009 Jun 30:1278:66-74. doi: 10.1016/j.brainres.2009.04.049. Epub 2009 May 3.

Abstract

This study was performed to understand the anatomical substrates of amygdaloid modulation of feeding-related peptides-containing neurons in the lateral hypothalamic area (LHA). After biotinylated dextranamine (BDA) injection into the central amygdaloid nucleus (CeA) and immunostaining of melanin-concentrating hormone (MCH)- or orexin (ORX)-containing hypothalamic neurons in the mouse, the prominent overlap of the distribution field of the BDA-labeled fibers and that of the MCH-immunoreactive (ir) or ORX-ir neurons was found in the dorsolateral part of the LHA, and the labeled axon terminals made symmetrical synaptic contacts with somata and dendrites of the MCH-ir or ORX-ir neurons. It was further revealed that nearly all the BDA-labeled axon terminals in the dorsolateral part of LHA were immunoreactive for glutamic acid decarboxylase, an enzyme for conversion of glutamic acid to gamma-aminobutyric acid (GABA). The present data suggest that the CeA is involved in the regulation of feeding behavior by exerting its GABAergic inhibitory action upon the MCH- and ORX-containing LHA neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amygdala / cytology*
  • Amygdala / metabolism
  • Animals
  • Axons / metabolism
  • Axons / ultrastructure*
  • Feeding Behavior / physiology
  • Female
  • Hypothalamic Hormones / metabolism*
  • Hypothalamus / cytology*
  • Hypothalamus / metabolism
  • Immunohistochemistry
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Melanins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Electron, Transmission
  • Neural Pathways
  • Neuropeptides / metabolism*
  • Orexins
  • Pituitary Hormones / metabolism*

Substances

  • Hypothalamic Hormones
  • Intracellular Signaling Peptides and Proteins
  • Melanins
  • Neuropeptides
  • Orexins
  • Pituitary Hormones
  • melanin-concentrating hormone