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Parenting with the Brain in Mind
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DRUGS AND THE BRAIN
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MODULE
TEN
PART
1
by John Joseph
Drugs and the Brain
What’s this about?
Welcome to the first of six articles that
examine how drugs affect the brain and the
quality of young people’s lives. I’ve tried to
provide you, and your children with objective,
honest and accurate information. Many
parents find it difficult to discuss drugs with
their kids because they don’t understand
much about the drugs, particularly the
modern variety. Secondly, because they fear
that talking about drugs will highlight that
lack of understanding. As a consequence,
most young people learn about drugs from
other young people, or those who have a
vested interest in dealing with them. So, the
aim of the next six articles is to inform and
educate, not to moralise or frighten. We reexamine how chemicals in the brain operate
at the microscopic level and we detail the
actions of drugs at those points. You’ll learn
more about drugs in these articles than most
users will ever know!
Drugs destroy lives and communities, undermine
sustainable human development and generate crime.
Drugs affect all sectors of society in all countries;
in particular, drug abuse affects the freedom and
development of young people, the world’s most
valuable asset.
United Nations Political Declaration on Global Drug
Control (1998)
What are drugs?
Just mention the word, drugs, and a whole array of
images race through the mind. From the relief of the
surgeon’s knife or a ritualistic ceremony to the stoned
junkie and the fist wielding drunk. Drugs have been
with humans for a long, long time.
Definition
I define drugs as ingested substances
that place a person in a state outside of his or
her normal range of operations.
Under my definition, is love a drug? No. Love is not
a substance ingested nor is love a response to a
substance ingested. Under my definition, is caffeine
a drug? Yes. Caffeine is an ingested substance that
at low to medium doses increases alertness and the
capacity to concentrate.
To place a person outside his or her normal range
of operation, the substance must interact with the
central nervous system (CNS).
The brain, the hub of the CNS, has ingenious methods
for keeping its excitatory and inhibitory states
under control. At its most basic level, when neurons
are in their excitatory state they are 'firing' to
carry electrical and chemical messages which fulfill
designated functions. However, when neurons are in
their inhibitory state, they are actively supressed so
that they do not 'fire'. This natural state of affairs
is fundamental to normal brain function. It prevents
chaotic states arising and allows focus of attention.
Drugs, especially drugs of abuse, affect both the
excitatory and inhibitory states. In overly excited
states, particular areas of the brain race out of
control. In overly inhibited states, functions may
be temporarily lost, including thinking processes, a
range of emotional states, sleep and wake cycles,
responses to pain, and even breathing.
Neuroscientists have found that almost all drugs of
abuse can produce pleasure by activating (putting
into excitatory states) specific groups of neurons
collectively termed the brain reward system. The
system is typically in an excitatory state when we
satisfy our appetite to eat and typically changes
to an inhibitory state when we overeat. In other
words, the brain's reward system becomes active
with actions that are associated with survival such as eating, drinking, exercising and procreating.
When we fulfil these functions, the brain responds
with a cascade of neurotransmitters that provide
pleasurable feelings. Because many drugs of abuse
inappropriately excite the reward system, users want
to repeat the experience and therefore the drug use.
(Source: Society for Neuroscience).
According to neuroscientist, Antonio Damasio,
feelings of pain and pleasure or some quality in
between are the bedrocks of our minds. Drug users
aim to stimulate the feelings of pleasure. But,
things can go terribly wrong. Some users report
‘downers.’ Others have died in drug induced inhibitory
brain states. There are no drugs of abuse meant
to activate feelings of sorrow, depression or to
cause death. These feelings are typically, rebound
effects from the high states or, in the case of death,
quantities of the substance have been ingested that
generate lethal excitatory or inhibitory states.
However, the effects of drugs cannot be fully
explained by activation of the brain reward system. (I
will examine this further in the next article).
Why do kids take drugs?
The appeal of drugs is that they change the way
you feel and the way you perceive your world. Kids
take drugs for any number of reasons. Some of the
most widely reported are: to feel good; to loosen up
and be free of inhibitions; to stay up all night; be
accepted by a peer group; forget worries; have fun
and feel amazingly happy; enjoy music and dancing
more; experiment and feel the thrill; escape feelings
of isolation; be rebellious; chill out; get sleep; feel
confident.
Feelings, not logic, drive the impulse to do drugs.
How do drugs work?
To answer that question we need to re-examine how
neurons work. Basically, neurons are like most cells
in the human body. They are held together by a cell
membrane, a living coating of lipids (fats) and protein.
What makes them different is that they have long
“tentacles” growing out in different directions.
Neurons look a little like uprooted trees turned upside
down. The branches growing out of the central cell
body are known as dendrites. A special branch, called
the axon, extends down to connect to other neurons
much like the trunk of a tree. Whereas trees tend to
absorb water from the roots and release gases into
the air through their leaves, neurons work in reverse.
They get their signals from their dendrites (leaves)
Drugs and the Brain
of serotonin on serotonin neurons and regulating
moods. Cocaine is an example of a re-uptake drug
of abuse because it suppresses the re-uptake of
dopamine, one of the reward system’s major pleasure
chemicals. Longer exposure to dopamine causes the
drug's 'high'.
Neurotransmitters are of major importance in
determining emotions, feelings, thinking, moods, and
mood disorders.
Scientists have identified about 50 neurotransmitters
so far but there may be around 200 – 300 of them
and an associated 200 – 300 receptors, including
subtypes. Neurotransmitters are responsible for
activating networks of neurons throughout the
brain.
Their levels fluctuate according to our diet, patterns
of exercise, patterns of thought, states of wellness
and, pertinent to this series of articles, the substances
we ingest.
Summary
and pass them on through their axon terminals
(roots). The human brain has billions of them. They
are both the store of information and the method of
transmission through the brain.
to flow to other neurons, across thousands of
synapses at once, thereby contributing to their firing
thresholds. This all happens in thousandths of a
second.
Typically, the terminals of one neuron connect
with the dendrites of many other neurons. They
don’t actually touch each other - they leave a
tiny gap, known as a synapse. It is here where
neurotransmitters (chemical messengers) flow from
terminals on the axons of the sending neuron to
receptor points on the receiving neuron, usually
on the dendrites. These messengers don’t flow
constantly, they “explode” out of the sending neuron
during a “firing” event. A neuron fires when it
reaches its “firing threshold" - much like blowing up
a balloon. Every balloon is slightly different, but when
the limit of the balloon’s rubber has been exceeded,
the balloon will explode.
What do Neurotransmitters do?
The arrival of the neuron pulse down the axon to
the terminals triggers a release of neurotransmitters
from storage sites called vesicles into the synapse.
Neurotransmitter molecules then bind, in a lock- and
key- type arrangement, to receptors on the receiving
neuron. The act of binding is like a switch or a tap;
either contributing to the receiving neuron’s firing
threshold or inhibiting it. Once the neurotransmitters
have completed their jobs they must be cleared away,
otherwise the neuron (or muscle) they interconnect
with would constantly remain under their influence
and further signaling would be impossible.
Neurons receive different types of signals from
other neurons on a regular basis. Excitatory signals
send the neuron a little closer to its firing threshold.
Inhibitory signals raise the firing threshold, meaning
that more excitatory signals will be required to make
the neuron fire. In our balloon analogy, excitatory
signals are like more air being pumped in, whereas
inhibitory signals are like making the balloon’s rubber
thicker. The signals create a chemical imbalance in
the neuron, which builds up in the dendrites. When
the threshold is reached, this imbalance causes a
chemical chain reaction to rapidly spread or “pulse”
down the axon to the terminals. The arrival of this
pulse in the terminals causes neurotransmitters
Neurotransmitters are cleared away by one of three
processes. Some are broken down by enzymes and
removed through the blood stream (hence their
presence may be detected in blood or urine samples).
Others diffuse away to regions of the brain where
there are no receptors to bind with while others are
transported back to their vesicles for release again
(called re-uptake).
Serotonin is a neurotransmitter which is produced by
the brain. One of its roles is to regulate moods.Some
types of medicinal drugs, such as the antidepressant
Prozac, act as a serotonin re-uptake inhibitor - that
is, it prevents the serotonin from being cleared away
from the synapse - thereby prolonging the effect
The least
I need to know
Straight talk about drugs beats moralising
and threats. Your kids’ exposure to drugs is
probably greater than you think because kids
learn about them by talking to other kids.
Intervene. Become knowledgeable so you can
talk-the-talk and provide the advice your kids
seek. Always keep in your mind, your kids
learn about drugs such as nicotine, alcohol,
pills and the like by observing what you do.
Be the role model you want your kids to
become.
References
(Items marked * are available from Mind Webs).
Log on to www.mindwebs.com.au
or call Cathy Joseph for a catalogue
(08) 8358 6993.
Dennis Trewin (Australian Bureau of Statistics)
Illicit Drug Use, Sources of Australian Drugs
www.abs.gov.au
*Antonio Damasio, Looking for Spinoza
*Miriam
Miriam Stoppard
Stoppard, Australian Drugs Info File
Society for Neuroscience, Brain Facts, A Primer
on the Brain and Nervous at www.sfn.org
Next Issue
– Module
10, Drugs and the Brain
Part 2