PSYCHONEUROIMMUNOLOGY

THE MIND-BODY CONNECTION

Breaking down the word:

• psycho—emotional behavior

• neuro—hypothalamic/pituitary axis

• immuno—immune system involvement

• -logy—study of

Anecdotal evidence of a brain-body connection:

• Sara• shaman• placebo

Review of electrochemical neurotransmission

role of neurotransmitters

putative neurotransmitters

peptides

Peptides is a “buzz” word for understanding psychoneuroimmunology (PNI)

“PSYCHO” PART

• higher cortical centers communicate with the emotional brain via the limbic system

• Papez Circuit (1937)—anatomical substrate for emotion

“NEURO” PART

• primary function of the hypothalamus is to control the pituitary

• this occurs in two ways—direct (posterior pituitary) and indirect (anterior pituitary)

Direct control occurs in the posterior pituitary via oxytocin (OXY) and arginine vasopressin (AVP)

both are chains of amino acids also called

peptides

Indirect control occurs in the anterior pituitary—messages stop at the median eminence and release releasing factors

examples: GH and GHRH; FSH and FSHRH;

they are also peptides (hormones in body)

“IMMUNO” PART

immune system (IS)

• one function of IS is recognition of self v non-self

• another function is maintenance of homeostasis—a delicate balance that is interrupted infrequently, but results in pathology when it is

Work of IS is carried out by T-cells and B-cells

T-cells (thymus) eliminate antigens by attacking them directly or by initiating a cascade of events that results in the release of lymphokines—”natural drug” of IS: structurally a peptide product of T-cells

B-cells (bursa of Fabricius) secrete antibodies that search out antigens and combine with them to form immunoglobulins

IMMUNE SYSTEM AND STRESS (DISEASE)

• 200 A.D.—Galen notes that melancholy women (yellow bile) were more likely to develop cancer than sanguine women (blood)

• 1920s—Cannon introduced fight or flight—nervous system arousal to stressful stimuli

• 1980s—Norman Cousins, an editor of a large east coast newspaper and astute lay person self-prescribed comedy films for reducing his own recovery time—Marx Brothers, Three Stooges, Candid Camera

IMMUNE SYSTEM AND CENTRAL NERVOUS SYSTEM

• Direct innervation of IS by CNS

bone marrow innervated by vagus nerve (X)

CNS structures project fibers to the thymus

spleen is innervated by CNS fibers

• Various peptides are found in gut tissue where immune actions may be initiated

• IS peptides affect thymocyte production and lymphocytes

• Weiderman (1987) proposed that peptides act as a “transducer” between experience and disease and hypothesized that every peptide found in the CNS will eventually be shown to have a peripheral role as well

• Candace Pert suggested that peptides play a significant role in the holistic approach to mind-disease paradigm

• Role of alternative medicines

• What do you think now?– about Sara– about shaman– about the placebo effect