of limbic–autonomic circuit development of the amygdalaorbitofrontal tract. At
this time the primary stimulation required is loving skin-to-skin contact. These
tactile interactions are vital to optimal development and participate in shaping
ongoing synapse formation. Violations of the innate agenda for infant development
needs, such as separation from the mother, generates a protest-despair response
commonly referred to as “hyperarousal and dissociation”.
Hyperarousal— The hypermetabolic “protest” response is one of intense
activity to reunite with the mother. The sympathetic autonomic nervous system
is suddenly and significantly activated, increasing heart rate, blood pressure, tone
and vigilance; frantic distress is expressed in crying then screaming. This state of
autonomic ergotropic arousal produces excessive levels of stress hormones resulting
in a hypermetabolic brain state.
Dissociation—After hyperarousal the hypometabolic “despair” response
occurs involving numbing and detachment. Dissociation is similar if not identical
to the freeze response. This is an automatic parasympathetic regulatory strategy
that occurs in hopeless situations to foster survival by the risk of feigning death.
In this passive state of profound withdrawal, endogenous opiates are increased
to produce analgesia, immobility and inhibition of cries for help. The individual
passively disengages to conserve energies, temperature, heart rate and blood
pressure decreases, and there is a massive rise in stress hormones.
Intense relational stress exposes the nervous system of the infant to hyperarousal
and dissociation which then increase the risk for developing severe psychopathologies
and health problems later in life. Since both the sympathetic and parasympathetic
sides of the infant’s developing brain become hypertonal this leads to conflicting
biochemical alterations. The HPA axis and vagal tone increases dramatically and
toxic neuroendochrine chemistry develops with associated alterations in calcium
metabolism and apoptosis. Thus truncated and deficient wiring occurs which
shows up as neurosis, ineptitude for lasting relationship, and various other mental,
emotional and behavioral pathologies.
The hippocampus nerves are not myelinated at birth and gradually undergo
myelination during our social environment in the first few years of life, this
probably accounts for our lack of consistent conscious memory of infancy. Pain
and distress, whether it be from physical or from relational trauma, changes the
NMDA receptors allowing them to open more easily and stay open longer. This
in itself would be a factor in the excitability of hyperarousal and the shutdown and
atrophy of dissociation through over activation of NMDA receptors (glutamate
toxicity).
Research in the last few years has shown that new nerve cells may even develop
in areas of the adult brain, including the hippocampus, the area that is important
for making new memories. Recent evidence suggests that one factor leading to new
neuron growth maybe physical and mental activity. So the hippocampus nerves
can be enrichened by use, and can be impoverished by lack of use, trauma and
stress. Trauma affects our capacity for cortical control over the limbic system to regulate
bodily homeostasis.