Chronic psychosocial stress regulates the expression of both GR and MR mRNA in the hippocampal formation of tree shrews

Citation
U. Meyer et al., Chronic psychosocial stress regulates the expression of both GR and MR mRNA in the hippocampal formation of tree shrews, HIPPOCAMPUS, 11(3), 2001, pp. 329-336
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
HIPPOCAMPUS
ISSN journal
1050-9631 → ACNP
Volume
11
Issue
3
Year of publication
2001
Pages
329 - 336
Database
ISI
SICI code
1050-9631(2001)11:3<329:CPSRTE>2.0.ZU;2-F
Abstract
A persistent hyperactivity of the hypothalamic-pituitary-adrenal axis and t hus elevated glucocorticoid levels are main neuroendocrine features of depr essive symptomatology in humans. The broad range of effects that are set of f by glucocorticoids is mediated by glucocorticoid receptors (GRs) and mine ralocorticoid receptors (MRs), which themselves are subject to autoregulati on. In order to investigate the impact of longlasting psychological stress on corticosteroid receptor mRNA expression in the hippocampal formation, we employed the psychosocial stress paradigm in male tree shrews (Tupaia bela ngeri). By in situ hybridization studies and semiquantitative evaluation of stress-induced changes of GR and MR mRNA expression at the single-cell lev el, brain tissue from subordinate animals which were exposed to 27 days (1 h/day) of social confrontation was compared to that of nonstressed animals. Four weeks of stress exposure resulted in a downregulation of CR mRNA in t he dentate gyrus and hippocampal subfields CA1 and CA3 of subordinate male tree shrews compared to controls. The MR mRNA content in these subfields of the anterior hippocampus was also clearly reduced. On the contrary, in a m ore posterior location on the longitudinal axis of the tree shrew hippocamp us, the MR message was increased in subfields CA1 and CA3 and in the dentat e gyrus. These results suggest a relevance of the stress-induced regulation of both corticosteroid receptor subtype mRNAs in a naturalistic challengin g situation. Moreover, the differential regulation of MR mRNA along the ros trocaudal axis of the hippocampus adds another feature to the heterogenous composition of this structure. Hippocampus 2001;11:329-336. (C) 2001 Wiley- Liss, Inc.