Amygdaloid axons innervate melanin-concentrating hormone- and orexin-containing neurons in the mouse lateral hypothalamus.
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.
Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo, Japan.
Sawako
S
Nakamura
Toshiko
T
Tsumori
Shigefumi
S
Yokota
Tatsuro
T
Oka
Yukihiko
Y
Yasui
D000679:Amygdala / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure*; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D007028:Hypothalamic Hormones / Q000378:metabolism*; D007031:Hypothalamus / Q000166:cytology* / Q000378:metabolism; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008543:Melanins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission; D009434:Neural Pathways; D009479:Neuropeptides / Q000378:metabolism*; D000068797:Orexins; D010907:Pituitary Hormones / Q000378:metabolism*
D007028:Hypothalamic Hormones; D047908:Intracellular Signaling Peptides and Proteins; D008543:Melanins; D009479:Neuropeptides; D000068797:Orexins; D010907:Pituitary Hormones; C019463:melanin-concentrating hormone