c-Fos immunoreactivity in selected brain regions of rats after heat exposure and pyrogen administration.
We determined c-Fos immunoreactivity (Fos-IR) in selected hypothalamic nuclei, the organum vasculosum of the laminae terminals (OVLT) and somatosensory cortex of rats after hyperthermia induced by exogenous heat exposure, Gram-negative or Gram-positive pyrogen administration. The magnitude of Fos-IR was similar in thermoregulatory hypothalamic nuclei of rats after heat exposure or lipopolysaccharide (LPS) injection, despite the different origins of the hyperthermias. Heat-induced hyperthermia was associated with increased Fos-IR in the somatosensory cortex. LPS, but not heat exposure or injection of killed Staphylococcus aureus cells activated OVLT neurons. The OVLT may thus not be a port of entry for humoral mediators of Gram-positive bacterial fevers.
du Plessis
Irné
I
Brain Function Research Unit, School of Physiology, University of the Witwatersrand Medical School of Physiology, 7 York Road, Parktown 2193, South Africa. swarti@physiology.wits.ac.za
Mitchell
Duncan
D
Niesler
Carola
C
Laburn
Helen P
HP
D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D002452:Cell Count / Q000379:methods; D006358:Hot Temperature; D007150:Immunohistochemistry / Q000379:methods; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000008:administration & dosage*; D008297:Male; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D011749:Pyrogens / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D008070:Lipopolysaccharides; D016760:Proto-Oncogene Proteins c-fos; D011749:Pyrogens