Psychological Physiology in Social Anxiety Disorder and
Shyness
Ruy Miranda
Social Anxiety Shyness Info
To understand the probable neurophysiological
action mechanism of medication and psychotherapy in Shyness and social
phobias, it is necessary to understand the neurons'
language. We will review now how the impulses go
from one nervous system cell, a neuron, to another.
The neurons are large cells with many projections
(dendrites) from the cellular body. These projections extend
from a few microns to sometimes as much as a meter.
Any function, such as thinking,
moving, sleeping, looking, or feeling, involves the integration
of an unknown number of neurons in specific brain areas,
as well as the nervous structures of the organisms outside the brain.
The neurons interconnect in complex chains. The message
travels through each neuron as electric impulses. All indications
point to the fact that the impulses are transmitted in the same way
in all the neurons, that is, as electric signals.
March of Impulses
The electric signals
are ions (atoms or group of atoms that received or lost
electrons) with positive and negative charges formed along
the neuron as a result of chemical and physico-chemical
reactions. These reactions terminate
in some place of the neuron membrane. Some particularities:
* A few ions stay in the interior of the neuron; others
stay outside.
* These ions move from the interior of the neuron to the
outside and from the outside to the interior of the neuron
through pores in the membrane.
* The ions with positive charge are potassium, sodium
and calcium ions. The largest are potassium ions.
* Chemical and physico-chemical reactions cause electric
currents in the neuron.
* These reactions end at some point of the neuron.
How is information passed on in the form of electric
signals to the next neuron?
The passage is through substances called neurotransmitters.
What a neurotransmitter
is – A neurotransmitter is a substance
that transmits a signal in the nervous system,
including the brain, from one neuron to another
or others. It is necessary because the
electric current does not cross the small space that exists
between two connected neurons. That substance
is stored in the neuron that produced
it in a region called pre-synapse. It
passes the electric impulse from one neuron to
the another in a region called synapse.
Synapse –
It is made up of structures of two connected neurons.
Each neuron has many structures for connections
at different points of the projections from the cell body
(dendrites), as well as at the end of a long
projection (called axon).
Let us imagine a segment of
such an electric current. A neuron, which we will call neuron
A, is situated in any position in a neuron chain. Neuron
A binds itself to neuron B, which binds itself to neuron
C and so on successively. To put this into
a scheme:
Neuron A – Synapse – Neuron B – Synapse –
Neuron C – etc.
In order for the electric impulse from neuron
A to go to neuron B, the intermediation of a substance
in the synapse is necessary because the reactions terminate
at some point of the membrane. That substance is a neurotransmitter.
The same thing occurs in the passage of the impulse from neuron
B to neuron C and so on. To put this into a scheme:
Neuron A – Neurotransmitter – Neuron B – Neurotransmitter
– Neuron C – etc.
Thus, the neurons are messengers
of positive and negative electric signals (the signals
of the ions). Neuron A— just as B and C and all the others
in a sequence—neither thinks nor makes decisions.
It is as "dumb" as the computer you are using, i. e., it only
transmits positive and negative electric signals. Let us put
it into a scheme:
Electric impulse in the neuron A – Neurotransmitter in the synapse
– Electric impulse in the neuron B – Neurotransmitter
in the synapse – Electric impulse in the neuron C – etc.
Particularities in the passage
of the impulse from one neuron to another – The
neuron membrane, as well as that of any other
cell, is made up of substances (molecules) organized
so as to leave spaces (pores) through which substances needed for cell survival and the exercise of special
functions come in and go out SELECTIVELY. These
molecules are different from those that originate the ions
and respective electrical charges in the neurons. On the other
hand, the pores are different in the vicinity of the
synapses. These are the reasons why the electric impulses
terminate in some place of the membrane, near the synapse.
The impulse in
neuron A that reaches the synapse regions discharges
or activates the neurotransmitter, which, in turn,
binds to certain structures (called receptors) of neuron
B's membrane. This connection triggers the
reactions in neuron B. So, we say that the neurotransmitter
bears a chemical signal.
Neuron B receives the chemical signal
and starts the chemical reactions that generate ions with positive and negative charges. These
reactions go in the direction of the synapse with neuron C.
And the process repeats itself.
You can see the alternation
of electric impulses and chemical signals. Let us put
it in a scheme:
Electric impulse in the neuron A – Chemical signal (neurotransmitter)
in the synapse – Electric impulse in the neuron B – Chemical
signal (neurotransmitter) in the synapse – Electric impulse
in the neuron C – etc.
Neurotransmitter Production
Neuron A produces a neurotransmitter
in a region close to the synapse with neuron B and
discharges it in the synapse. Neuron A, which
passes the stimulus on to neuron B, is known as the proximal
neuron, while neuron B is called distal.
Neuron B produces a neurotransmitter
in a region close to the synapse with neuron
C and discharge it in the synapse. Thus, neuron
B is proximal as regards neuron C and neuron
C is distal vis � vis neuron B. Neuron C will
be distal as regards neuron D and so forth and so on.
Thus, all the neurons produce neurotransmitters.
Besides passing a chemical signal, all of them
receive a chemical signal.
The structure of the distal neuron in
the synapse where the chemical signal comes in is called
receptor.
Neurotransmitter regulation – There is a regulation of the amount of neurotransmitter
in the synaptic space. It seems to be made in the proximal
neuron. In addition to producing the neurotransmitter in a region
close to the synapse, the proximal neuron injects more
neurotransmitters into the space or removes eventual excesses
and stores them. That regulation by the proximal neuron
would involve:
– production of the neurotransmitter;
– storage of the neurotransmitter close to the synapse;
– discharge of the neurotransmitter in the synaptic space;
– re-uptake of the neurotransmitter and re-storage.
In certain cases the neurotransmitter is
de-activated (changes its chemical structure) just after it passes
the stimulus to the distal neuron. When the proximal
neuron comes in contact with the following stimulus,
the neurotransmitter is re-activated.
Locations Liable to Have Flaws
One can deduct where problems may occur:
*disorder in the production of neurotransmitter in
the proximal neuron;
*the proximal neuron does not inject enough amounts of neurotransmitter
in the space, in spite of having them stored in its interior;
*the proximal neuron injects an excessive or insufficient amount of neurotransmitter
into the space;
*the proximal neuron does not adequately activate the neurotransmitter;
*the proximal neuron does not adequately remove the neurotransmitter
from the space;
*the synaptic space ends up with too much or too little neurotransmitter;
*the distal neuron displays chemical or physical-chemical alteration
in the structure situated in the membrane in the synapse region, called
receptor;
*alteration in the receptor "distorts" the electric
signal when it arrives as a chemical signal, through the neurotransmitter,
to the distal neuron.
It is impossible, with current instruments,
to know which defect occurs in any person. You can
see the long list of possible defects; and there are more which are not included here. However, whatever it may be, the exactness
of the signal transmitted by the neurotransmitter becomes compromised.
It is possible that the evolution of nanotechnology will provide
some information in the near future.
Neurons A, B, C, D, and all
the others have a greater number of synapses. Indeed, one single neuron can have thousands.
Example: 6,000 synapses. You can imagine the extremely complex
network of 100 billion computing units (neurons) inter-connected
by thousands of synapses.
If one or more of these defects
occur in a set of neurons exercising the same function, the
messages will be distorted. Examples: A defect in the
set of neurons involved with humor may lower humor (depression)
or raise it (elation, mania); another set involved with the
state of alertness may lower it (inattention) or raise it (excessive
attention, apprehension, anxiety and possibly Shyness and phobias).
It is expected that medications correct
those defects in Shyness and social anxieties. However,
as we don't know where the defect is, the action of
one medication can be good for a given person and ineffective
for another.
Neurotransmitters, Plasticity of the System, Psychotherapy
Neurotransmitters and Psychotherapy – To indicate psychotherapy for problems which may result
from chemical reactions may seem paradoxical.
Yet, psychological problems do affect neurotransmitters outside of the brain—and probably in it too. Example: The expectation preceding a school exam can alter the activity of the neurotransmitter that regulates the bladder's sphincter so that the student urinates several times . Likewise, perceiving a strange person as threatening and judging yourself unable to confront him (one of the so-called psychological problems) could affect the activity of neurotransmitters in some specific region. Changes
in these two beliefs ("the strange is threatening"
and "I am unable to confront him") could lead to some
changes in the activities of the neurotransmitters or in the related structures. Psychotherapy can promote
changes like that.
Plasticity of the System and Psychotherapy – On the other hand, the extensive neural
network has a property called plasticity. At the core,
plasticity is a constant change in the ways of the ion
currents. In the day-to-day activities, the synapses that inter-connect
the imagined neurons A,B,C and D in our example are not fixed.
On the contrary, they change constantly. Such change is necessary
to maintain the dynamic equilibrium (homeostasis) proper
to any living system. It is believed that the re-direction
of the electric currents underlies what we call learning and
memory, and that learning stimulates the formation of
new ways for the flows. And all psychotherapies
are, at the core, a learning process that must stimulate
such new ways.
It may be
now understandable why many professionals
think that it is better to combine psychotherapy and medication in Social Phobia/Anxiety and in severe Shyness.
Electric Flow and Genes
There is evidence that some psychological
problems have a genetic basis. Some cases of Shyness
and Social Anxiety are among them. The possible explanation for this fact can be in specific genes,
called "pacemaker current," concerned with the encoding
of ion channels (pores in the membrane). Mutations
in these ion channel genes might contribute to some disorders,
caused by a lower plasticity of the system.
For these cases, if the evidence comes to be confirmed, we depend
on the discovery of new families of medication.
In another article,
we will see how this information can help to understand how
the antidepressants act.