Fever: Hypothalamic Responses During Inflammation Modulate Immune Response

HYPOTHALAMIC CONTROL OF LYMPHOID TISSUE IN IMMUNE RESPONSE

A critical part of fighting off any infection is the activation of an appropriate immune response. During a sickness response, prostaglandin E2 acts on neurons in the medulla, amygdala, and hypothalamus, which results in an increase in the secretion of corticotropin-releasing hormone (CRH) into the pituitary portal circulation, elevated adrenocorticotropic hormone (ACTH) secretion by the pituitary gland, and increased levels of circulating adrenal corticosteroids. Cortisol then causes demargination of white blood cells that are adherent to the endothelium of blood vessels, elevating the circulating white blood cell count. Lymphocytes in a variety of tissues also respond directly to ACTH, and to a number of other circulating hormones.

There is also direct sympathetic innervation of the lymphoid tissues. This input, which is also under hypothalamic control, may control the production and trafficking of specific lymphocyte subsets.

Only gold members can continue reading. Log In or Register to continue