Transcript The Hijacked Brain - Vermont Law School

The Hijacked Brain
Addiction and the Brain
Bob Wolford
Vermont Law School
November 13, 2015
Fun facts about Neurons
Here are some interesting statistics* about neurons in humans and other
animals (remember that these are averages because there is a lot of
variability in the nervous system!):
 Average number of neurons in the human brain = 100 billion
 Average number of neurons in the octopus brain = 300 million
 Rate of neuron growth during fetal development in utero = 250,000
neurons/minute
 Diameter of a neuron = 4 to 100 microns
 Length of giraffe primary afferent axon (from neck to toe) = 15 feet
 Velocity of signal transmitted through a neuron = 1.2 to 250 miles/hour
 There are as many neurons in the human brain as stars in the Milky Way
 The number of ways information travels in the human brain is greater than the
number of stars in the universe
 What if we lined up all the neurons in our body? How long would that
line stretch?
 Let's assume that one neuron is about 10 microns long. Remember, this
is just an example, because neurons come in all different sizes. So, if
we line up 100 billion neurons which are 10 microns long...
100,000,000,000
neurons x 10 microns
= 1,000 km or about
600 miles!
A Different State of the Brain
Addiction…
IS
…irrational and at times the behavior of people struggling with
addictions seems mystifying, even to themselves…
Are the changes in the addicted brain purely the consequence
of drug use or is the brain of the habitual user somehow
susceptible before drug use begins?
What does the research tell us?
Dopamine is a neurotransmitter. It is a chemical
messenger that helps in the transmission of signals
in the brain and other vital areas. Dopamine is found
in humans as well as animals, including both
vertebrates and invertebrates
Pre-frontal Cortex and Limbic
System
Pre-Frontal Cortex
 This vital region of the brain regulates thought in terms of
both short-term and long-term decision making. It allows
humans to plan ahead and create strategies, and also to
adjust actions or reactions in changing situations.
Additionally, the PFC helps to focus thoughts, which enables
people to pay attention, learn, and concentrate on goals. This
area is also the part of the brain that allows humans to
consider several different yet related lines of thinking when
learning or evaluating complex concepts or tasks. The
prefrontal cortex houses active working memory.
PFC - continued
 Unfortunately, the PFC is one of the brain regions most
susceptible to injury. When the pathways between the
prefrontal cortex and the rest of the brain are damaged or
altered, serious personality changes can result. This is
logical, since the PFC regulates so many behavior and
thought-processing pathways, but can be debilitating and
difficult for the injured individual as well as his family and
social circle. A person who had been reserved and
contemplative can become reckless and impulsive after such
an injury. Likewise, a formerly outgoing person can become
quiet and withdrawn.
PFC - continued
 A damaged PFC can negatively impact a person's ability to
assess situations or perform tasks, particularly those of a
moral or ethical nature. Since social judgements are made in
this brain area, these people can also be rendered unable to
discern appropriate behavior or suffer from emotional
distress, such as irrational fears, anxiety, euphoria, and
irritability. Some studies have found weak interconnections
between the PFC and the rest of the brain among criminals,
sociopaths, drug addicts, and schizophrenics, which may be
further evidence of the importance of this part of the brain in
individual behavior and decision-making.
The limbic system is the portion of the brain that deals with
three key functions: emotions, memories and arousal (or
stimulation). This system is composed of several parts, which
are found above the brainstem and within the cerebrum. The
limbic system connects parts of the brain that deal with high
and low functions.
Stressed Brain
Environmental factors
Epigenetics
Like silt deposited on the cogs of a finely tuned machine after
the seawater of a tsunami recedes, our experiences, and those
of our forebears, are never gone, even if they have been
forgotten. They become a part of us, a molecular residue
holding fast to our genetic scaffolding. The DNA remains the
same, but psychological and behavioral tendencies are
inherited. You might have inherited not just your grandmother’s
knobby knees, but also her predisposition toward depression
caused by the neglect she suffered as a newborn.
Epigenetics, cont’d
Or not. If your grandmother was adopted by nurturing parents,
you might be enjoying the boost she received thanks to their
love and support. The mechanisms of behavioral epigenetics
underlie not only deficits and weaknesses but strengths and
resiliencies, too. And for those unlucky enough to descend
from miserable or withholding grandparents, emerging drug
treatments could reset not just mood, but the epigenetic
changes themselves. Like grandmother’s vintage dress, you
could wear it or have it altered. The genome has long been
known as the blueprint of life, but the epigenome is life’s Etch A
Sketch: Shake it hard enough, and you can wipe clean the
family curse
Hope = Neuroplasticity
 As time goes by, science provides more and more evidence
that our brains are malleable and continually changing in
response to our lifestyle, physiology, and environment.
 This concept is called neuroplasticity, or brain plasticity—
meaning, we are literally reforming our brains with each
passing day. It used to be thought that our brains were static,
except during some critical developmental periods, but today,
we know this isn’t true.
 Our brains possess the remarkable ability to reorganize
pathways, create new connections and, in some cases, even
create new neurons throughout our entire lifetime.
Neuroplasticity, cont’d
The Sea Gypsies, or Moken, are a seafaring people who
spend a great deal of their time in boats off the coast of
Myanmar and Thailand, have unusual underwater vision -twice as good as Europeans. This has enabled Mokens to
gather shellfish at great depths without the aid of scuba gear.
How do the Moken do this? They constrict their pupils by 22
percent. How do they learn to do this? Is it genetic?
Neuroscientists argue that anyone can learn this trick. Simply
put, the brain orders the body to adapt to suite its needs.
Treatment implications
 Medications
 Vaccines
 Cognitive-behavioral therapies
 Ongoing recovery support
Thousands of candles can be lighted from a single candle, and
the life of the candle will not be shortened. Hope never
decreases by being shared.
Buddha paraphrased