Coordinate regulation of Fos and Jun proteins in mouse brain by LiCl

EXPRESSION of the bZIP transcription factor c-Fos in the nucleus tractus so litarius (NTS) of the brain stem may allow for genomic encoding of an uncon ditioned stimulus (US) during taste aversion learning. Dimerization of c-Fo s with other bZIP proteins of the Jun family is necessary to enable transcr iptional efficacy at the AP-1 sequence of putative target gene promoter reg ions. The present study examined the regulation of Fos and Jun proteins by LiCl. Double immunofluorescence labelling revealed that LiCl causes a coord inate upregulation of c-Fos, FosB and JunB, and these proteins are colocali zed in a majority of cells examined in NTS, parabrachial nucleus (PBN), and central nucleus of the amygdala (CeA). This study demonstrates that a coor dinate signalling response occurs in relevant brain regions in response to LiCl. (C) 1999 Lippincott Williams & Wilkins.