Neuroendocrinmmunology

Reichlin, Seymour. (1993, October). Neuroendocrineimmune interactions. The New England Journal of Medicine, 329, 12461253.

Reichlin (1993) summarizes the varied aspects of neuroendocrinimmunology. The term, "neuroendocrinimmunology" is defined as "the study of neuroendocrine influences on the function of immunocompetent cells". The subject also includes the elucidation of how immunocompetent cells alternatively influence the nervous and endocrine systems. Taken together these interactions are of great physiologic consequence.

It has long been known that the mechanisms responsible for biologic homeostasis are modulated by both the nervous and endocrine systems. More recently, it has been discovered that these two systems interact with the immune system. Furthermore, this interaction occurs in both directions. Neuroimmunology is the study of immune reactions which involve the central nervous system (CNS). Neuroimmunomodulation, in contrast, relates to effects which the nervous system has on the immune response.

Reichlin begins his paper by elaborating on each of these two topics (1246). He describes how the brain itself can be involved in immune responses. Various cell types including monocytes, lymphocytes, macrophages, microglia, endothelial cells, and smoothmuscle cells may become involved. All of these cellular components of the immune system secrete inflammatory mediators. One of the most important of these mediators is a group of peptide hormones

in. As noted, one means by which the CNS modulates the immune system is through the hypothalamus. The secretion of hypothalamic hormones is controlled by suprahypothalamic stimuli. Such stimuli may include environmental signals, sleep rhythms, and stress. Upon secretion, these hormones' actions are then mediated through their target glands. Yet another way in which the CNS influences immune responses involves the sympathetic nervous system and the adrenal medulla. Both secrete catecholamines. Catecholamines such as epinephrine can have several effects on immunity including leukocytosis, lymphopenia, and the inhibition of naturalkillercells (1248). As Reichlin's paper explains, these interactions are often due to the fact that the nervous, endocrine, and immune systems, all share regulatory peptides (1246). One example of this involves lymphocytes. These cells are known to contain proopiomelanocortin mRNA. Proopiomelanocortinderived peptides include CNS compounds such as corticotropin and the endorphins. In addition, regulatory peptides such as the cytokines may also play an important role in local neuroimmunomodulatory responses to inflammation (12481249). They do this primarily by providing a negative feedba

Category: Science - N