The Effects of Stress And The Brain
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Transcript of The Effects of Stress And The Brain
Understanding the Impact of Stress on Brain Development and Learning
Merriam-Webster define stress as:
A physical, chemical or emotional factor that causes bodily or mental tension
Acute stress is general short-term with a clearly defined beginning and end
Chronic stress is long-term and prolonged stress with no clear ending
Both acute and chronic stress trigger the physiological stress response
Triggering of the sympathetic nervous system which prepares the body to deal with perceived threat by: ◦ Increase of heart rate and blood pressure
◦ Increase of cortisol – “stress” hormone which has anti-inflammatory and immunosuppressive properties
◦ Decline of parasympathetic activity which regulates “automatic” bodily functions and maintains homestasis
◦ Shorter form of the serotonin transporter is associated with vulnerability to increased response to stress by developing depressive illness and alcoholism
◦ An allele of the monoamine oxidase A gene result in more vulnerability to abuse in childhood, increased risk of becoming an abuser & show antisocial behaviors.
Early abuse can result in life long emotional reactivity and stress hormone reactivity –both associated with cognitive decline and shorter lifespan in animal studies
Stress reduction in infants can be influenced by maternal bonding through a variety of factors◦ Physical proximity
◦ Modeling
Early patterns “hard-wire” the stress response –critical period during 1st nine months
Males most typically mirror the fight or flight response
Females engage fight or flight AND befriend
There is an inverted relationship between learning and levels of cortisol
During acute stress, higher levels of cortisol result in: ◦ Enhanced immunity
◦ Enhanced memory
During chronic or prolonged stress, the increased levels of cortisol result in:
◦ lower immune response
◦ Impaired cognitive functioning
The Hippocampus is the brain structure primarily responsible for learning and memory
The Hippocampus is highly sensitive and malleable
Cortisol decreases and retracts the dendritic growth in the hippocampal area
Within the Hippocampus, is the dentate gyrus, a structure which seems to play a role in the memory of sequences of events
It has high plasticity and is constantly producing new neurons, even throughout adult life.
Certain types of stress suppress neurogenesis and cell survival in the dentate gyrus
Cortisol inhibits long-term potentiation – cell sensitivity in communication
Adolescent brain is more receptive to long-term potentiation without interference
Repeated or chronic stress causes dendritic shortening in the medial prefrontal cortex
The results in impairment in attention set shifting
Both acute and chronic stress produce dendritic growth in neurons in the amygdala.
The results of include: ◦ Increases anxiety
◦ Increased aggression
In animal research, chronic stress causes atrophy of neurons in the hippocampus and prefrontal cortex
and
Hypertrophy of neurons in the amygdala
Results: ◦ Decreased learning and memory
◦ Increased anxiety and aggression
The results from animal studies are mirrored in humans through a loss of hippocampal volume and an increase in amygdala volume in MRI studies
PET scans also demonstrate altered patterns of activity in the related brain areas during stress
Learn stress management – variety of techniques
Problem-focused –changing the stressor
Emotion focused –changes our response to the stressor
Physical
Cognitive
Emotional
Behavioral
Physical Techniques:
Exercise Meditation
Relaxation
Cognitive Techniques:
Social Comparisons Re-Evaluation
Distraction
Emotional Techniques:
Social Support Release
Laughter
Behavioral Techniques:
Helping Others
Optimism is associated with lower cortisol production and higher heart rate variability (showing higher parasympathetic activity)
Optimistic people are, on average, healthier and live longer than pessimistic people
Optimistic people have higher levels of life satisfaction
Poor self-esteem has debilitating effects: ◦ Increased levels of cortisol
◦ Inability to regulate cortisol levels under stress
◦ 12-13% loss of hippocampal volume
Improve sleep quality and quantity
Have a good social support system
Maintain a positive outlook on life
Maintain a healthy diet
Avoid smoking
Regularly exercise – moderate activity
Build positive self-esteem
Learn successful stress management
McEwen, B.S. Protective and damaging effects of stress mediators: central role of the brain. New England Journal of Medicine. 1998, 338: 171-179
Q & ARobin Donaldson,