Understanding the brain- Neurobiology of Everyday life

1. UNDERSTANDING THE BRAIN-
NEUROBIOLOGY OF EVERYDAY LIFE
FINAL PEER GRADED ASSIGNMENT
PTSD

2. WHAT IS PTSD?
• While studying about Post Traumatic Stress Disorder, it’s
important to understand that PTSD is considered to be a
psychological injury rather than a mental illness.
• Neuroanatomical studies have identified changes in major brain
structures of those with PTSD — the amygdala, the prefrontal
cortex and hippocampus – showing that there are significant
physical changes within the brain as a result of trauma.

3. The People
• Observing the interviews of certain people who suffer from
PTSD, it has come to my notice that that they mentioned
having good and bad days, but also they said that they were
anxious all the time.
• It could be seen in their expressions that they were fighting
the anxiety, the fear at that particular moment too. Most of
them were soldiers or police officers who now are completely
devastated and it’s hard for these people to open up because
that means revisiting the entire experience.
• They mentioned living in constant fear and hence, checking if
everything is safe over and over again.

4. SYMPTOMS-
• The main symptoms of PTSD are:
• Re-living the traumatic event- through distressing, unwanted memories, vivid nightmares
and/or flashbacks. This can also include feeling very upset or heart palpitations or being
unable to breathe when reminded of the traumatic event.
• Avoiding reminders of the traumatic event- including activities, places, people, thoughts or
feelings that bring back memories of the trauma.
• Feeling wound-up- This might mean having trouble sleeping or concentrating, feeling angry
or irritable, taking risks, being easily startled, and/or being constantly on the lookout for
danger
• Negative thoughts and feelings- such as fear, anger, guilt, or feeling flat or numb a lot of the
time. A person might blame themselves or others for what happened during or after the
traumatic event, feel cut-off from friends and family, or lose interest in day-to-day activities.
• It is not unusual for people with PTSD to experience other mental health problems as well,
like depression or anxiety. Some people may develop a habit of drug abuse as a way of
coping.

5. Effect Of Trauma on Hippocampus
• Under normal conditions, when a memory is built, the hippocampus blends
together all the elements of a memory from all the sensory areas. Initially, short-
term memories are stored in the hippocampus, but when they are no longer
required as ‘conscious memories’, the hippocampus processes these into other
parts of the brain (to create longer term memories).
• As mentioned above however, the
hippocampus tends to reduce in volume
in those with PTSD and so the recording and formation
of new memories and retrieval of older memories in
response to specific environmental stimuli can become
distorted.
• The hippocampus is also responsible for distinguishing between
past and present memories, and so those with PTSD can lose the
ability to discriminate between past and present experiences (resulting in extreme
flashbacks and reliving their trauma).

6. Effect of Trauma on the Ventromedial Prefrontal
Cortex
• The ventromedial prefrontal cortex region of the brain
generally regulates negative emotions (such as fear).
• Due to this region shrinking in
• those with PTSD, the ability
to regulate
• these emotions is reduced – causing fear,
anxiety, and extreme stress responses even when faced with
things not connected – or only remotely connected – to their
original trauma.

7. Effect of Trauma on the Amygdala
• Trauma has been shown to increase activity in the amygdala region.
• This region of the brain helps us process emotions, and is
also linked to fear responses. It uses the hippocampus to analyze
situations from the past to
ascertain answers to questions
such as ‘Is this safe?’, and most significantly in PTSD ‘Do I need
to start up the stress responses and trigger hormones?’. As you
may imagine, if this region of the
brain is hyperactive, and is connecting with an already ‘broken’
hippocampus, the effects it will
have on our emotional regulation will be a distorted view of a situation.
• Studies have shown that PTSD sufferers exhibit hyperactivity in the amygdala in response to
stimuli that are connected to their trauma – however, the amygdala is so hyperactive in some
patients that they exhibit fear and stress responses even when they are ‘simply shown
photographs of people exhibiting fear’. This hyper-exhibition and constant state of feeling
fear and stress is what make people suffering from PTSD this vulnerable.

8. Effect of Trauma on Cortisol Levels
• The biologic alterations observed in PTSD do not uniformly resemble those associated with other
types of stress. For example, cortisol levels have been lower than normal in some studies of
patients with PTSD, however corticotropin-releasing factor in cerebrospinal fluid appear to be
increased.
• This pattern differs from the patterns associated with brief and sustained periods of stress and with
major depression, which are typically associated with increased levels of both cortisol and
corticotropin-releasing factor.
• These psychological and biologic data supports the hypothesis that the development of PTSD is
facilitated by a failure to contain the biologic stress response at the time of the trauma, resulting in
a cascade of alterations that lead to PTSD.
• Furthermore, it has been shown that patients with chronic PTSD have even more increased
circulating levels of norepinephrine and reactivity of adrenergic receptors. These alterations, in
addition with the findings that thyroid hormone levels are generally increased in patients with
PTSD, also explain some of the somatic or physical symptoms of the PTSD.
• Understanding how PTSD alters brain chemistry is critical to empathizing with the symptoms of
PTSD, devising treatment methods, and to providing the answers as to why some people develop
PTSD from trauma, and others do not.
•

9. Thoughts About The Course-
• Since a mere small age, I have been interested in knowing how the human
brain and body works and why.
• This course was very detailed and answered many of the “whys” I had.
• Professor Mason is an amazing teacher who knows her subject very well
and made the course interactive by sharing personal stories and examples!
• To know about the intricacies of neurobiology was really intriguing and I
might seriously consider a career in this domain.
• This has inspired me to research more about neurobiological disorders as
well and maybe even work on them.