title: Vasopressin neuron activation and Fos expression by stimulation of the caudal ventrolateral medulla.
abstract: The present study demonstrates that projections ascending from the caudal ventrolateral medulla have direct effects on the expression of the immediate early gene c-fos and of the arginine-vasopressin gene in neurosecretory cells of the hypothalamic supraoptic nucleus. Intense Fos-like immunoreactivity (Fos-LI) was observed in many magnocellular neurons of the supraoptic nucleus after electrical stimulation of the caudal ventrolateral medulla. In sham-operated rats, Fos-LI was absent or present in very few magnocellular neurons in the supraoptic nucleus. Fos-LI was visible in neurons expressing arginine-vasopressin, and was seen rarely in oxytocin neurons by double-immunostaining method. This study showed that 76% of all Fos-positive cells were arginine-vasopressin immunoreactive, whereas only 4% of them showed oxytocin immunoreactivity in the supraoptic nucleus. With in situ hybridization, a high level of arginine-vasopressin mRNA was noted in the supraoptic nucleus 3 h after stimulation of the caudal ventrolateral medulla; the expression was highest 6 h after the stimulation compared with the same region in sham-operated animals. These findings suggest that noradrenaline, released from the axon terminals originating from the caudal ventrolateral medulla, may participate in the regulation of gene transcription of arginine-vasopressin in response to physiological stimuli.
authors.affiliation: Department of Anatomy, Showa University School of Medicine, Tokyo, Japan. shioda@med.showa-u.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Shioda
authors.forename: M
authors.initials: M
authors.lastname: Iwase
authors.forename: I
authors.initials: I
authors.lastname: Homma
authors.forename: S
authors.initials: S
authors.lastname: Nakajo
authors.forename: K
authors.initials: K
authors.lastname: Nakaya
authors.forename: Y
authors.initials: Y
authors.lastname: Nakai
mesh_terms: D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001127:Arginine Vasopressin / Q000096:biosynthesis*; D001370:Axonal Transport; D004558:Electric Stimulation; D005786:Gene Expression Regulation / Q000502:physiology*; D016762:Genes, fos; D017403:In Situ Hybridization; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010835:Phytohemagglutinins; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D013495:Supraoptic Nucleus / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D010835:Phytohemagglutinins; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; C100156:leukoagglutinins, plants; D001127:Arginine Vasopressin