Anxiety Disorders & 5HT Receptors
igoddard at erols.mom
Thu Mar 28 11:33:11 EST 2002
The following report cites a study that links adult anxiety
in mice to problems with serotonin receptors during infancy.
These findings might seem to only support a biological model
of psychiatry, which sees psychological problems as stemming
strictly from biological problems. However, the New Scientist
report quotes Dr Solomon Snyder, who makes a psychosocial link:
"He also thinks the finding might help explain the
impact of maternal neglect. 'Perhaps variations in
serotonin-sensitive neurons and serotonin receptors
in early life account for the importance of maternal
nurturing in preventing emotional disturbance in
adults,' Snyder says."
That sees the brain as it is, a complex intersocial computer.
While there may be chemical assaults or genetic aberrations,
it seems to me that the most common cause of neurological
states would stem from psychosocial interactions especially
during early years of neurological development. While Freud's
view that your Mother's treatment of you as a child is a major
aspect of your psychology has been widely rejected as the field
turns toward a biological model, we may find that he was right,
and moreover, that his view does not violate a biological model.
"What we are today comes from our thoughts of yesterday,
and our present thoughts build our life of tomorrow. Our
life is the creation of our mind." -- Buddha (Dhammapada)
Anxiety disorders may be seeded early
19:00 27 March 02
The roots of anxiety disorders may reach back to infancy, say US
scientists. They have found that mice that lack certain receptors in
the first days of their lives are unusually anxious in adulthood -
even if the receptors are later restored.
The neurotransmitter serotonin has long been associated with mood.
Recently, it has been found that mice lacking receptors for serotonin
are abnormally anxious, though no one was sure which receptors in
particular were responsible.
To track these down, Cornelius Gross at Columbia University in New
York and his colleagues created a line of mice that had receptors for
theneurotransmitter serotonin only in certain parts of the brain - the
hippocampus, the cortex and the amygdala. His group found that even
with only these serotonin receptors functioning, the mice behaved
The next step involved a neat trick of genetic engineering, in which
the researchers were able to turn the receptors on and off by
administering antibiotics. If they gave the mice doxycycline, the
receptors were soon deactivated. But when they turned them off in
adulthood, the animals continued to behave normally.
The breakthrough came when the team tested for a critical period
earlier in life. The researchers fed doxycycline to female mice while
pregnant, so that their pups' receptors were inactive during the
embryonic and early postnatal stage. By adulthood the offspring's
receptors were working again.
When tested as adults, these mice showed extreme signs of anxiety -
spending much more time hovering around the corners of their cages
and huddling inside enclosed spaces, and being too nervous to eat -
exactly as the knockout mice had behaved.
"This suggests that in a mouse there's a time when neurons are
actively finding their connections or pruning themselves," says Gross.
Serotonin might have an important role in establishing those
connections. During this critical period, the receptors have to be
stimulated and a cascade of events must be set in motion if the animal
is to behave normally.
Solomon Snyder, at Johns Hopkins University School of Medicine in
Baltimore, Maryland, calls the technique "ingenious" and hopes it will
be used to better understand other neurotransmitters and behaviours.
He also thinks the finding might help explain the impact of maternal
neglect. "Perhaps variations in serotonin-sensitive neurons and
serotonin receptors in early life account for the importance of
maternal nurturing in preventing emotional disturbance in adults,"
"Assuming that we can equate developmental stages in mice and humans,
these findings might be relevant to brain development and the genesis
of anxiety in people too," he adds.
"To lengthen thy life, lessen thy meals." Ben Franklin
More information about the Neur-sci