Tuesday, November 13, 2007

tempted by the fruit of another.

Here is your biochemistry lesson of the day.

A human being is driving. A human being is in a car accident. This human being's hypothalamus, stimulated by the perception of outside events, begins to release CRH, a hormone which travels to the pituitary glands. At the pituitary gland, CRH binds to secondary sites, where adrenocorticotropic hormone (ACTH) is released. ACTH travels to the adrenal cortex, where is stimulates the adrenal glands to produce and secrete cortisol. Cortisol, also known as the "stress hormone", affects almost every tissue in the body.

Cortisol, once its released, will circulate through the whole body. It raises blood pressure, starts the breakdown of proteins and stored complex sugars (energy supplies) in the body, suppresses the immune system, decreases bone formation, and reduces seratonin levels in the brain.

Interestingly, cortisol also affects memory. A rush of cortisol would cause the brain to store quick short-term memories -- flashbulb memories. Too much cortisol impedes the brain's ability to lay down a new memory at all, and also makes it more difficult to access already stored long-term memories.

Cortisol, in women, also stimulates the release of oxytocin. Oxytocin, which has a minor counter-active effect on cortisol, also dictates how the mind will react to stress levels. Oxytocin is the same hormone released when women are giving birth; it creates a sense of calm, well-being, a desire to nuture, and positive feelings of attachment. Oxytocin is also released during an orgasm.

Not coincidentally, oxytocin also acts as an anesthetic for the mind. When released, it prevents storage of traumatic or painful memories.

So at both ends of the spectrum - during times of great stress and at times of pleasure, the human body tries to protect itself. (Turns out those ends are closer than we think.) It keeps us from remembering the reality of an event, which would, in retrospect, be recalled as less painful, less unfortunate, better. Memories through a hazy rearview mirror.

So when you remember:
a horrible car accident
birth
mindblowing sex

you may not be remembering it perhaps as it was, but as your body wants you to remember it.

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