<prompt> Febrile response in CNS is mediated by?Bacterial toxinIL-1IL-6All  <response>: Ans. is a i.e., Bacterial toxin; b i.e., IL-1; c i.e., IL-6 Pyrogenes Pyrogenes are substances that cause fever. Pyrogens may be exogenous or endogenous Exogenous -- Bacterial toxins Endogenous -- IL-1, TNF-a, IL-6, Interferons, Ciliorys neurotropic factor These pyrogenes increase the level of PGE2 in the hypothalamus that elevates the thermoregulatory set point and causes fever. 