Opioid Peptide Production by the Immune System

Abstract

The nervous, endocrine, and immune systems are intimately connected through mutually acting regulatory systems. The immune system is highly specialized in its recognition of and reaction to specific antigens from internal as well as external sources. The brain is specialized in recognition and response to internal and external emotional and physical stimuli. Both systems have their own characteristic responses to these stimuli. However, the response patterns of the two systems are partly overlapping, that is, they both produce mediators such as cytokines and neuropeptides that can act as communication pathways for the two systems. Moreover, the immune system expresses receptors or binding sites for every neurotransmitter or hormone tested so far, thereby enabling the immune system to recognize and to respond to neuroendocrine signals (Blalock & Smith, 1985).