Role of Neuropeptides in the Bidirectional Communication Between the Immune and Neuroendocrine Systems

Abstract

Vertebrates respond to infection and inflammation with a complex series of intercellular communication signals involving the immune, nervous, and endocrine systems. Recent investigations have shown that the immune system is subject to neural and endocrine control, and that it exerts in turn a reciprocal effect on the nervous system. In addition, the immune system is capable of producing neuropeptides, and the nervous system is able to secrete cytokines. This chapter summarizes the evidence for the production and function of neuropeptides in this regulatory relationship. The neuropeptides discussed here include corticotropin (ACTH), β-endorphin, vasoactive intestinal peptide (VIP), somatostatin (SOM), and substance P. Overall, a rapidly expanding body of evidence indicates that neuropeptides and cytokines are the common signal molecules that mediate bidirectional communication between the immune and neuroendocrine systems.