ABSTRACT
This chapter shows that the activation of the immune system induces profound alterations in the central nervous system (CNS) and in several neurotransmitters at this level, as well as modifications in food and water intake, locomotion, sexual behavior, social interactions and sleep. It summarizes the available evidence of the reciprocal interactions between immune-active molecules and neurotransmitters in the CNS and discusses the possible relevance of these interactions in the regulation of the sleep/wake cycle. Muramyl peptides (MPs) are the monomeric building blocks of bacterial cell wall peptidoglycans and are released by mammalian macrophages during the digestion of bacterial cell walls. MPs are well-known somnogenic substances; the administration of MPs tailored from bacterial cell walls induces slow-wave sleep and fever. Many studies suggest an interaction of cytokines with the different glutamate receptors. This may be important in brain injury and neurodegeneration.
