Synaptic relationships between proopiomelanocortin- and ghrelin-containing neurons in the rat arcuate nucleus.
Both proopiomelanocortin (POMC) and ghrelin peptides are implicated in the feeding regulation. The synaptic relationships between POMC- and ghrelin-containing neurons in the hypothalamic arcuate nucleus were studied using double-immunostaining methods at the light and electron microscope levels. Many POMC-like immunoreactive axon terminals were found to be apposed to ghrelin-like immunoreactive neurons and also to make synapses with ghrelin-like immunoreactive neuronal perikarya and dendritic processes. Most of the synapses were symmetrical in shape. A small number of synapses made by ghrelin-like immunoreactive axon terminals on POMC-like immunoreactive neurons were also identified. Both the POMC- and ghrelin-like immunoreactive neurons were found to contain large dense granular vesicles. These data suggest that the POMC-producing neurons are modulated via synaptic communication with ghrelin-containing neurons. Moreover, ghrelin-containing neurons may also have a feedback effect on POMC-containing neurons through direct synaptic contacts.
Guan
Jian-Lian
JL
Department of Anatomy, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
Okuda
Hiromi
H
Takenoya
Fumiko
F
Kintaka
Yuri
Y
Yagi
Michiko
M
Wang
Lihua
L
Seki
Mayumi
M
Hori
Yasunori
Y
Kageyama
Haruaki
H
Shioda
Seiji
S
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism* / Q000648:ultrastructure; D054439:Ghrelin / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D011333:Pro-Opiomelanocortin / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure
D054439:Ghrelin; D011333:Pro-Opiomelanocortin