CYTOKINES AND THE NERVOUS-SYSTEM .1. EXPRESSION AND RECOGNITION

Cytokines are a heterogeneous group of polypeptide mediators that have been associated classically with activation of the immune system and inflammatory responses. An increasing number of related mediators is n ow included in this category and most of them have been shown to act o n a variety of tissues, including the PNS and CNS. Cytokines and their receptors are expressed in tissues of these nervous systems, and migh t derive from invading immune, or resident, cells. Trauma in periphera l tissues might also induce cytokine-mediated events in the CNS, via e ither the circulation or secondary induction within the brain. In this first of a two-part review, the general properties, expression and re cognition of these cytokines with respect to the nervous system are di scussed. .