Page 19 - Winter2008

help prevent excess tension, anxiety, burnout, the hypothalamus, an almond-sized gland-like portion of the brain that
and feelings of self-defeat and help support the communicates with the master gland, the pituitary. The hypothalamus
confrontation of challenges with the attitudes releases corticotropin-releasing hormone (CRH), which tells the pituitary
necessary for success. to release its own signal into the blood, which in turn tells the adrenal
gland to ramp up its production of cortisol. This system is called the hy-
CORTISOL: FLIGHT OR FIGHT pothalamus-pituitary-adrenal axis or the HPA axis. 20
We often hear that it is not stress itself that A number of lines of evidence suggest that the regulation of the
is bad, but our reaction to stress. If we confront fight-or-flight response by the hypothalamus is disturbed in anxiety and
our challenges and overcome them, they will depression. Mice that are genetically altered to make too much CRH
help promote our success, but if we fear them, or that are injected with CRH exhibit behaviors characteristic of these
run from them, and worry over them, we will two mental illnesses. Depressed adults and those who have experienced
mentally and emotionally fall apart. traumatic experiences earlier in life have elevated levels of CRH in their
One of the potential reactions to stress is the cerebrospinal fluid, and this generally normalizes if they are treated with
fight-or-flight response. The adrenals produce effective therapies. A drug that antagonizes CRH reduced depression and
the hormone cortisol, which raises blood sugar, anxiety in a placebo-controlled trial, although the drug also proved toxic
increases muscle tension and strength, and pre- to the liver. 20
pares us for the extreme reactions necessary to The endocannabinoids derived from arachidonic acid are central
defend our lives when our survival is threatened. regulators of the HPA axis. When researchers physically restrain rats for
This reaction is necessary in certain situations thirty minutes, their blood levels of corticosterone—the equivalent of
but needs to be regulated. If we react to the minor cortisol in the human—shoot up seven-fold. When they are given a drug
stresses in our daily lives with the fight-or-flight that raises the level of natural endocannabinoids in the brain, however,
response, we will be constantly anxious and will corticosterone only rises two- to three-fold. It is difficult for us to say for
21
eventually burn out or develop chronic condi- sure whether this suppression of the fight-or-flight response is good or bad,
tions like heart disease. because we do not know what the ideal blood levels of adrenal hormones
The fight-or-flight response is controlled by are for a given stressful situation. It would be more informative to look at

FIGURE 3.
THE ELEVATED ZERO MAZE

The elevated zero maze is shaped like a zero (an open circle) and is elevated off the ground. The rat has the choice be-
tween spending time in the open spaces or the closed spaces, thus facing the internal conflict between its fear of predators
and its desire to explore its environment. More time spent in the open spaces is taken to indicate a lower level of anxiety.

WINTER 2008 Wise Traditions 19