Sunday, June 13, 2010

Does stress affect memory?


PHYSIOLOGY TUTORIAL
Does stress affect memory?
The primary area of the brain that deals with stress is its limbic system. Because of its enormous influence on emotions and memory, the limbic system is often referred to as the emotional brain.
During times of stress, the body responds by releasing hormones that trigger physical changes. Chronic stress can have negative effects on our well being, leading to higher blood pressure, increased abdominal fat and decreased bone density.
Exposure to stress can damage hippocampus. The damage results from a kind of chain reactions or feedbackloop.The cycle begin when adrenal glands release steroid hormones called glucocorticoids into the bloodstream. The hippocampus has a high density of receptors for glucocorticoids and in normal circumstances it helps regulate the production of stress hormones. However hippocampus is particularly sensitive to these hormones. Studies have shown that hippocampal neurons of rodents die when they are exposed to glucocorticoids for months and the neuronal dendrites atrophy when they are exposed for few weeks of stress. As a result of the damage stress hormones continue to be secreted at increased levels, resulting in even more damage to the hippocampus
Because exposure to stress can damage the hippocampus and because hippocampus is an important brain structure associated with declarative memories for facts, researchers have been particularly interested in how stress affects our ability to remember new information.
Stress management is the solution, not stress elimination
Bear in mind that an appropriate stress response is healthy and necessary part of life. one of the things it does is to release NE ,the excitatory neurotransmitter.NE is needed to create new memories, it improves mood, problems feel like more challenges, which encourage creative thinking that stimulates our brain to grow new neuronal connections .
Sympathetic system turns on fight and flight response. In contrast the parasympathetic system promotes relaxation response. The challenge in this day and age is not to let the sympathetic system stay chronically aroused. This may require knowledge of techniques that work to activate our relaxation response.
Lifestyle, personality, and even genetic makeup influence our emotional and physiological responses to stress. But we can modify those responses by making changes in how we act, think, relate, move, and relax.
P.S –Refer, Stress and destress posted by Dr.R.vinodha in vinodha’s blog on Sep 2, 2007.

2 comments:

Sabarinath said...

thanks for the information mam.does prolonged intake of corticosteroids affect memory?

Dr.Vinodha said...

Dr.Sabarinath,
I appreciate your enthusiasm. Researches suggest that long-term corticosteroid therapy is associated with difficulty in concentration, diminished verbal memory, and impairment of long-term memory. The renowned brain researcher Robert M.Sapolsky has shown that sustained stress can damage the hippocampus. Excessive cortisol is associated with difficulty to think or retrieve long term memories.
However the understanding mechanisms are unclear.