INDUCTION OF FOS-LIKE IMMUNOREACTIVITY IN THE RAT-BRAIN FOLLOWING PASTEURELLA-MULTOCIDA ENDOTOXIN ADMINISTRATION

The functional neuroanatomy of the immune system link to the CNS was i nvestigated by assessing neuronal activity with Fos immunohistochemist rY following systemic lipopolysaccharide (LPS) administration. Two hou rs after LPS robust Fos-like immunoreactivity (Fos-IR) was observed in several nuclear groups in the brain including the paraventricular and supraoptic nuclei of the hypothalamus, central nucleus of the amygdal a, and nucleus of the solitary tract. A similar but diminished pattern of Fos-IR was present at 6 hours and was absent 24 hours after LPS ad ministration. Investigation of the functional neuroanatomy of the acut e phase reaction could prove to be critical in enhancing the ability o f individuals to combat insults such as tissue damage and inflammation .