Synaptic relationships between proopiomelanocortin- and ghrelin-containing neurons in the rat arcuate nucleus

• Published in: Regulatory peptides Vol. 145; no. 1; pp. 128 - 132
• Main Authors: Guan, Jian-Lian, Okuda, Hiromi, Takenoya, Fumiko, Kintaka, Yuri, Yagi, Michiko, Wang, Lihua, Seki, Mayumi, Hori, Yasunori, Kageyama, Haruaki, Shioda, Seiji
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Shannon Elsevier B.V 10-01-2008; Amsterdam Elsevier
• Subjects: Animals; Arcuate Nucleus of Hypothalamus - metabolism; Arcuate Nucleus of Hypothalamus - ultrastructure; Biological and medical sciences; Electron microscopy; Feeding regulation; Fundamental and applied biological sciences. Psychology; Ghrelin - metabolism; Hypothalamus; Immunocytochemistry; Male; Melanocyte stimulating hormone; Microscopy, Electron; Neurons - metabolism; Neurons - ultrastructure; Pro-Opiomelanocortin - metabolism; Rats; Rats, Wistar; Synapse; Synapses - metabolism; Synapses - ultrastructure; Vertebrates: endocrinology; Melanocyte stimulating hormone; Synapse; Feeding regulation; Hypothalamus; Electron microscopy; Immunocytochemistry; Feeding behavior; Rat; Arcuate nucleus; Rodentia; Central nervous system; Prohormone; Encephalon; Feeding; Pituitary hormone; Vertebrata; Mammalia; Neuron; Ghrelin; Animal; Proopiocortin
• ISSN: 0167-0115; 1873-1686
• DOI: 10.1016/j.regpep.2007.09.028

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.