Functions and mechanisms of interleukin 1 in the brain.

Interleukin 1 (IL-1), a cytokine with diverse actions, has been proposed as a mediator of both beneficial and detrimental responses to inflammation and injury. Many of the actions of IL-1, such as those on behaviour, neuroendocrine function, sleep, fever and metabolism, are mediated by the CNS, as described here by Nancy Rothwell. IL-1 can be synthesized and act locally within the brain to influence neuronal and glial function, and has been strongly implicated in normal brain development and responses to brain injury. A number of distinct sites and mechanisms of action have been proposed to explain these diverse effects of IL-1 in the brain, probably involving multiple receptor subtypes and complex interactions with neurotransmitters and neuropeptides.