Monday, February 05, 2007

Stress and its pernicious effects on our lives...

I was reading an excellent book by Joseph LeDoux (Synaptic Self – How our brains become who we are) and came across a remarkably succinct definition of stress and stress related damage on our brains and thought that I should draw a diagram to better understand it. I posted it here so that we could later refer to some of the flows involved (I plan to write a follow up post on some of the latest discoveries regarding stress). Please click on the image for a detailed view.
What is fascinating is that a behavior (stress response) that was evolved and fine tuned by our ancestors for use in one-off occasions to protect ourselves from impending attacks of wild beasts is now being experienced by all of us on a regular basis because of the pace of lives that we live out (the effects of this on our brains is far removed than what evolution had planned).

Well, there is clear evidence that the stress related changes in our bodies could directly effect our capacity to remember things and to a larger extent, have long term destructive effects on some of the most important structures within our brains. I hope you find this diagram useful. It is not as dense as it looks…

Some relevant definitions:
Hormone: Is a chemical messenger from one cell (or group of cells) to another. Hormones are produced by nearly every organ system and tissue type in an animal body. Hormone molecules are secreted (released) directly into the bloodstream.
Amygdala: It is a set of subcortical mass of neuronal cells that is important for perceiving in others and having in oneself emotional or affective behaviors and feelings (e.g. fear, anger). It got its name from its shape - like an 'almond'.
Peptides: Family of short molecules formed from the linking, in a defined order, of various amino acids (similar to proteins). Used for signalling among a host of other functions. Hormones are made of protein/peptides.
Hippocampus: Part of the brain located inside the temporal lobe (humans and other mammals have two hippocampi, one in each side of the brain). It plays a major part in memory and spatial navigation. The name derives from its curved shape in coronal sections of the brain, which resembles a seahorse (Greek: hippos = horse, kampi = curve).

2 comments:

Sunflower Optimism said...

Very interesting, Sunil. I had previously read about the cortisol and stress. I also read that cortisol is produced by the fat around the middle - so the more obese, the more cortisol one produces.

I think cortisol also affects inflammation - I remember reading that cortisol has an effect on RA. I can tell you for sure that stress definitely affects RA!

I didn't know about the deleterious affects of too much cortisol and the permanent damage that may cause. Good post, glad I took the time to go through it - thanks for going through the trouble to put it all together.

Sunil said...

Cortisol produced by the adrenal glands is considered necessary for controlling inflammatory processes in the body. Sometimes due to excessive stress, the adrenal glands are utilized to a point where the cortisol released is marshalled to produce bodily reactions to the ensuing stress leaving little cortisol to fight inflammation : thus leading to increased rheumatoid arthritis... - my little theory

Thanks for taking the time to skim through that flow chart - glad it made some sense...