title: Effect of acute imipramine administration on the pattern of forced swim-induced c-Fos expression in the mouse brain.
abstract: The forced swim test (FST) has been widely used for the preclinical evaluation of antidepressant drugs. Despite considerable differences in the protocol, equivalence of the FST for rats and mice has been rarely questioned. Previous research on the FST for rats revealed that repeated administration of antidepressant drugs attenuates the c-Fos response to swim stress in the hypothalamus and limbic regions. However, few studies have made similar investigations using the FST for mice. In the present study, we explored the mouse brain through immunohistochemistry staining for c-Fos after acute administration of imipramine or saline with or without a subsequent swim session. Imipramine enhanced the c-Fos density in regions of the central extended amygdala, while forced swim stress increased c-Fos expression in some hypothalamic (the ventrolateral preoptic nucleus and dorsomedial nucleus) and brain stem regions, which is consistent with previous reports. In contrast to previous literature with rats, swim stress brought a significant increase in c-Fos expression in the lateral septal nucleus and some other regions in the hypothalamus (the intermediate hypothalamic area, the paraventricular and arcuate nucleus) only in the imipramine-pretreated group, which has not been observed previously. In the arcuate nucleus, double immunostaining revealed that c-Fos was rarely co-expressed with proopiomelanocortin or tyrosine hydroxylase regardless of imipramine treatment. The present results suggest that the activation of several regions in the lateral septum and the hypothalamus underlies antidepressant-like effect in the mouse FST.
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Yanagida
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan. Electronic address: motomrak@npsych.med.kyushu-u.ac.jp.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Motomura
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Ohashi
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hiraoka
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Miura
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Kanba
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000008:administration & dosage*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D007099:Imipramine / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D013315:Stress, Psychological / Q000378:metabolism*; D013550:Swimming
chemical_list: D000928:Antidepressive Agents; D016760:Proto-Oncogene Proteins c-fos; D007099:Imipramine
keywords: Aggression area; Antidepressant; Arcuate nucleus