Chemical specificity of endotoxin-induced c-fos expressing neurons in the rat hypothalamus

• Main Author: Jackson, Andora T. K.
• Language: en_US
• Published: 2007
• Online Access: http://hdl.handle.net/1993/2021

It has been shown that intravenous (i.v.) injection of lipopolysaccharide (LPS), a powerful endotoxin derived from the outer coat of gram-negative bacteria, results in a dose- and time-dependent expression of the proto-oncogene c-fos in the brain. In particular, the region of the paraventricular nucleus (PVN) in the hypothalamus shows significant c-fos expression upon LPS treatment (134). This thesis examined some of the characteristics of this c-fos induction. Various staining procedures were used to determine the possible chemical specificity of the neurons activated during the endotoxin immune challenge. To examine more closely the role of nitric oxide in LPS-induced c-fos expression in the PVN, central injections of L-NAME, a nitric oxide synthase inhibitor, were used. To investigate further the possible mediators of the LPS-induced c-fos response, the effects of central administration of prostaglandin E2 (PGE2), a potent mediator of the immune response to LPS, was examined. The role of ascending catecholamine tracts in the central expression of c-fos after i.v. LPS (immune stress) and footshock (psychological stress) were examined in order to determine the effects of these neural inputs in the central response to stress. (Abstract shortened by UMI.)