Psychoneuroimmunology Flashcards
CNS connection to the immune system, direct and indirect?
direct: neuronal
indirect: neuroendocrine
direct is the innervation of primary (thymus, bone marrow) and secondary lymphoid organs (spleen) as well as the adrenal medulla
indirect is the CNS communicates hormonally with the immune system
What stimulates the bone marrow?
Noradrenergic fibers
What stimulates the thymus?
noradrenergic
cholinergic(ACh)
Peptidergic fibers (neuropeptides)
What stimulates the spleen?
noradrenergic
What stimulates the lymph nodes?
noradrenergic
Peptidergic
What does cortisol do?
anti-inflammatory reduces: cytokine production T and B cell reactivity NK cell activity
EPI, NE, GABA, ACH, Serotonin stimulate what, to synthesize and release what? What does this stimulate? What does this do?
- PVN of hypothalamus to synthesize and release CRH into the portal blood
- stimulates the release of ACTC into peripheral circulation
- ACTH causes the release of cortisol from the adrenal gland into circulation
What is the adrenal medulla innervated by? What activates the adrenal medulla
sympathetic nerve fibers (with ganglia in the hypothalamus)
-hypothalamus activates splanchnic nerves which in turn trigger chromaffin cells of the adrenal medulla to secrete catecholamines
What do epinephrine and norepinephrine do?
Act as neurotransmitters in the CNS and are released into circulation by adrenal medulla
- increase leukocyte mobilization
- –>increase in NK cell activity
Where do endorphins originate what do they do”
Originate from POMC (synthesized in pituitary after CRH stimulation) but can also be synthesized in immune competent cells
- play an important role in analgesia and euphoria
- increase T cell reactivity and NK cell activity
Where are enkephalins produced, what do they do?
-produced in the brain, pituitary, and adrenal gland (simultaneously with epinephrine and norepinephrine)
- play a role in analgesia
- can bind to the same opioid receptors as endorphins
*Endorphins act more like hormones while enkephalins act more like neurotransmitters
–increase T cell reactivity and NK cell activity
What are the types of stress?
- acute controllable emotional or mental stress
- chronic uncontrollable negative stress
An example of acute controllable stress is parachute jumping, what cells do you see immediately increase?
-Increase in number of circulating leukocytes-particularly NK cells
- HR
- cortisol-goes up more slowly and stays up
- epinephrine
- norepinephrine
- circulating mononuclear cells (T, Helper T, CD8, Monocytes, NK cells0
- increase in NK cell activity
These short lasting stress related immune modulations is associated with what?
increased catecholamine levels
-fight or flight
What happens if you administer epinephrine or norepinephrine?
-increase the number of circulating NK cells
What happens to the number of mononuclear cell populations after 1 hr?
- populations decreased because the cells have localized to the regional lymph nodes
- that way they can respond quickly to antigenic challenges
- effect is mimicked by the administration of catecholamines and cortisol
- leukocyte levels return to normal
What is redistribution to the lymph a consequence of?
- hormonal modification of adhesion molecules on the surface of the leukocytes ( increased expression of CD 11a)
- activation of cognate adhesion molecules on the surface of endothelial cells ICAM1
What usually happens once the immune system is mobilized and ready?
Cortisol switches energy to muscles for flight or fight
How do low cortisol concentrations affect the DHT response?
enhance it
HOw do high concentrations of cortisol effect the DTH response?
depresses it
How does chronic cortisol effect the DTH response?
decrease it
OVerall does acute stress enhance and chronic stress depress cell mediated immunity?
yes
What levels so you see decreased in chronic stress?
- decreased cytokine production (IL-1)
- decreased antibody production
How does chronic stress effect the flu?
- decreased cytokine response to influenza vaccine(IL-2)
- increased numbers of colds and flu