Acth

Corticosteroids

Adrenal gland

- Catecholamines

Enkephalins

Prolactin

Growth hormone

(3-Endorphin

Corticosteroids

- Catecholamines

Enkephalins

Figure 2 Some neuroendocrine pathways to the immune system. Many of the hormones released by the hypothalamus, pituitary and endocrine glands affect the activity of lymphocytes. In stress, hormones and neurotransmitters from the adrenal cortex (corticosteroids) and medulla (principally catecholamines and enkephalins) are especially important.

Figure 2 Some neuroendocrine pathways to the immune system. Many of the hormones released by the hypothalamus, pituitary and endocrine glands affect the activity of lymphocytes. In stress, hormones and neurotransmitters from the adrenal cortex (corticosteroids) and medulla (principally catecholamines and enkephalins) are especially important.

Mast cc9

Figure 3 Some immune system pathways to the nervous system. Various cytokines released by activated cells of the immune system modulate the activities of the autonomic and neuroendocrine systems. In addition, lymphocytes and other immune cells release some neurotransmitters and neurohormones.

Mast cc9

Figure 3 Some immune system pathways to the nervous system. Various cytokines released by activated cells of the immune system modulate the activities of the autonomic and neuroendocrine systems. In addition, lymphocytes and other immune cells release some neurotransmitters and neurohormones.

exert effects on the central nervous system and in some cases (notably IL-1 and IL-3) may act as intrinsic neuromodulators within the brain. However it is the neural effects of the cytokine IL-1 (and coordinate^- IL-6 and TNFa), released by macrophages during immune and inflammatory responses, which are the most well studied.

Activation of macrophages produces IL-1 and subsequently leads to altered electrical activity in the brain, and metabolism of the neurotransmitters norepinephrine, serotonin and dopamine in certain brain regions. These neural changes can also be produced by injected IL-1 and can be blocked by an IL-1 receptor antagonist. Does this mean then that immune-produced IL-1 acts directly on the brain? Certainly neurons in the preoptic nucleus have receptors for IL-1 (as well as IL-6 and TNFa) but because IL-1 is a relatively large, lipophobic protein it may have difficulty crossing the blood-brain barrier easily. An active transport mechanism could exist to carry IL-1 across the barrier, or alternatively, IL-1 might cross the vascular endothelium in regions of the brain, such as the preoptic nucleus of the hypothalamus, where the barrier is weak or absent. Another possibility is that IL-1 stimulates peripheral nerves, such as the vagus, to send afferent input to the brain This possibility was highlighted by recent findings that if the vagus nerve was cut just below the dia phragm, stress-induced, IL-l-mediated effects on the brain were considerably diminished.

How To Bolster Your Immune System

How To Bolster Your Immune System

All Natural Immune Boosters Proven To Fight Infection, Disease And More. Discover A Natural, Safe Effective Way To Boost Your Immune System Using Ingredients From Your Kitchen Cupboard. The only common sense, no holds barred guide to hit the market today no gimmicks, no pills, just old fashioned common sense remedies to cure colds, influenza, viral infections and more.

Get My Free Audio Book


Post a comment