Proinflammatory citokines role in regulation of normal and affected cerebral function represent a frontier that rapidly develop in neuroscience. Cytokines are molecules that are synthesized not only by the immune system, but also by cells in the central nervous system, including neurons, glia, and brain vascular cells. In the brain, cytokines can be neuroprotective or they can contribute to neurodegeneration. The role of cytokines in the regulation of normal and abnormal brain function represents a rapidly growing frontier in neuroscience. Cytokines are pleiotropic and redundant, and they can modulate the effects of neurotransmitters and neuropeptides; thus, in order to understand the effects of brain cytokines on apoptosis and toxicity, it is necessary to study the temporal and spatial expression of complex networks of cytokines, growth factors, neuropeptides, and neurotransmitters. This effort is currently in progress in many centers. Modulation of cytokine function in the central nervous system represents a new therapeutic strategy for neurodegeneration.