Behavioural, electrocortical spectrum power and body temperature changes after microinfusion of some lymphokines in the rat brain.

Interleukin-1, interleukin-2 and interleukin-3 injected into the third cerebral ventricle produce typical behavioural sedation and/or sleep and ECoG synchronization in rats. Much smaller doses were required to produce similar behavioural and ECoG spectrum power effects after infusion of interleukins into the locus coeruleus. Interleukin-1 and interleukin-3 induced pyrogenic effects while interleukin-2 produced no pyrogenic actions. These effects were blocked by specific anti-interleukin receptors monoclonal antibodies. In addition, naloxone was able to antagonize the central effects of IL-2 but it did not affect the typical changes induced by IL-1. These results are consistent with the hypothesis that the behavioural, body temperature and ECoG changes of these lymphokines are mediated by specific receptors.