title: Age-related changes in c-fos mRNA induction after open-field exposure in the rat brain.
abstract: In the present study, functional activation of brain regions was measured by the induction of c-fos and c-jun mRNA following exposure to a novel open field. Fischer 344 rats at 5 months, 14 months, and 21 months were exposed to a square open field for 20 min. Rats were then immediately sacrificed and their brains were examined for c-fos and c-jun mRNA using in situ hybridization. Control rats were sacrificed directly from their home cage. Results showed no significant age-related changes in locomotor activity. Autoradiogram analyses showed that open-field exposure induced c-fos mRNA throughout the brain, while c-jun mRNA was induced in a few brain regions. Aged rats showed a lower elevation of c-fos mRNA in the prelimbic cortex compared to 5-month rats. In addition, grain analyses revealed age-related decreases in c-fos mRNA induction in the medial prefrontal cortex, caudate, and ventral lateral septum. These findings indicate age-related changes in the induction of c-fos mRNA in certain brain regions following exploration of a novel environment.
authors.affiliation: Department of Cell Biology, Neurobiology and Anatomy, Loyola University Chicago, Stritch School of Medicine, Maywood, IL 60153, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Nagahara
authors.forename: R J
authors.initials: RJ
authors.lastname: Handa
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000033:anatomy & histology; D001923:Brain Chemistry / Q000502:physiology*; D004777:Environment; D007091:Image Processing, Computer-Assisted; D017403:In Situ Hybridization; D008297:Male; D009043:Motor Activity / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger