title: Fos activation in cultured tyrosine hydroxylase and oxytocin immunoreactive neurons.
abstract: Fos and other immediate early gene products are used as markers for neuronal activity. We identified Fos immunocytochemically after KCI-induced depolarization of cultured hypothalamic neurons. Five-day cultures were treated for 1 h with 50 mM KCI or media and fixed at 0, 0.5, 1, 2, and 4 h posttreatment. Sequential immunocytochemistry was performed to identify Fos immunoreactivity in tyrosine hydroxylase (TH)-immunoreactive (-ir) or oxytocin (OT)-ir neurons. Activated neurons [brown cells (TH-ir or OT-ir) with purple nuclei (Fos-ir)] were counted microscopically. KCI treatment resulted in an increased percentage of Fos-ir TH-ir and OT-ir neurons over control levels over the time course examined. Fos-ir peaked in TH-ir neurons at 0.5 to 1 h posttreatment, with levels returning to baseline at 4 h. Fos-ir in OT-ir neurons peaked at 2 h, and remained elevated at 4 h, showing prolonged activation. These results demonstrate that KCI-induced depolarization of cultured hypothalamic neurons increases Fos with a different time course in TH-ir vs. OT-ir neurons.
authors.affiliation: Department of Physiology and Pharmacology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157-1083.
authors.forename: L J
authors.initials: LJ
authors.lastname: Sim
authors.forename: M
authors.initials: M
authors.lastname: Morris
mesh_terms: D000818:Animals; D007031:Hypothalamus / Q000502:physiology; D007150:Immunohistochemistry; D009474:Neurons / Q000276:immunology* / Q000648:ultrastructure; D010121:Oxytocin / Q000378:metabolism*; D017680:Potassium Compounds / Q000494:pharmacology; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*
chemical_list: D017680:Potassium Compounds; D016760:Proto-Oncogene Proteins c-fos; D010121:Oxytocin; D014446:Tyrosine 3-Monooxygenase