When neutral proteins are produced, mild ASD will occur due to
inadequate production of synaptic adhesion proteins (neuroligin,
neurexin, MDGA1 and MDGA2) needed for normal mood, speech and behavior.
When a toxic protein results it would destroy the target sites, and
impaIr their functions.
On rare occasions, a mutant synaptic
adhesion protein may have an enhancing protein may lead to a
super-functioning ASD patient. Synaptic protein abnormalities have been
associate with autism and schizophrenia. In order to easily recognize an
abnormal pattern of child development, one needs to have a sense of
what is normal.
After having two normal kids a mom might get a
sense of what is normal in child development. But a new mom will need
help knowing what to expect. She needs to know that at birth, a newborn
baby will have a grabbing and reaching behavior or the startle reflex.
The newborn is also able to initiate facial grimace, as well as cry and
cling for attachment.
As early as 1 week a newborn can distinguish
mom's smell from dad's smell. A normal newborn, in the first couple of
months is attracted to bright, colorful, moving objects, and can
distinguish voice sound from ordinary noise. Prior to the 8th week, the
baby exhibits reflex (endogenous) smile. But by week 8, the baby
responds to faces with a smile (exogenous or social smile). By week 12,
the smile becomes selective for familiar faces only (preferential social
smile). The newborn quickly learns to draw attention to personal needs
by crying aloud.
The loud cry usually builds up from unhappy face
to grunting to sobbing to cry outburst with tear stream. As the child
grows older he/she learns to kick off bed covers in protest and roll
into ready to crawl position with head lifted up and eyes scanning for
parents. In general the manifestations of autism are related to the
child's tendency to be disinterested in the environment, to be
inflexible with habits and mannerisms, and to be emotionally numb. Two
early sign of inflexibility often overlooked in a newborn are the
selective feeding on only one breast and selective sleeping in only one
position.
The autistic newborn may also only fall asleep when the
room is pitch dark or clutching a specific part of his/her body. Some
may insist on having their thumb in their mouth before they can fall
asleep. One of the earliest obvious suggestions that something may be
wrong is the absence social smile between three to four months after
birth.
There may also be absence of eye contacts or tracking eye
movements. It becomes more obvious that something is wrong between ages 6
and 12, when a child fails to develop normal emotional, speech and play
patterns, and makes only repetitive sounds and hand movements.
Synaptic
failures between primary cortical sensory areas (visual, auditory, and
somatosennsory) and association cortex, prevents learning and memory
formation that occurs through the association of particular emotions
with specific stimuli, place and objects. Normally, the smiley face of a
mom breastfeeding her baby stimulates increased dopamine release in the
pleasure center (nucleus accumbens), and causes the baby to return a
smile whenever a physiologic need is met.
The pleasure of social
interaction by itself may directly create a positive memory in a normal
child through the hippocampus without nuerotransmitter surge in nucleus
accombens. The script recorded in the hypocampus is played over and over
by the autistic kid for every emotional situation, until there occurs a
strong intrusive override by way of teaching.
This accounts for
the repetitive and non-interactive, domineering style of communication
exhibited by autistic individuals. A negative emotion creates a
diminished desire for the stimulus, by reducing the level of dopamine,
which normally causes a craving for the stimulus. This association of
negative emotion with withdrawal occurs in the amygdala, the limbic
nucleus for harm avoidance.
Dopamine reduction is produced by a
surge of serotonin into the synapses, which creates the feeling of
satisfaction and switches off the stimulus. Two other neurotransmitters,
mGluR2 and mGluR3, inhibit the opening of dopamine receptors, thereby
further reducing its craving effect and increasing the harm avoidance
response. The craving response and harm avoidance response are modulated
by the ventromedial prefrontal cortical association area, which is the
center for problem solving reward with a strong kink to the limbic
system.
