This disorder is a clear example of how experiences and the memory of them result in behavioral alterations. Memory repression, and PTSD show two ways a memory can be integrated into a person's life either fully and vividly or seemingly not at all. The implications of this are that our experiences control us, we don't control them. New neurons are being synthesized and new synapses are forming continuously. The connections are influenced by past, present and suspected future experiences.
Various neurochemicals have different effects on neurons.
It was found that the storage of information in the brain is modulated by endogenous hormone systems or that the surrounding chemicals influence the new connections being made. Traumatic experiences are high stress situations and particular chemicals are released to cause the fear and the anxiety that the victim experiences. In fact, people with PTSD tend to have abnormal levels of key hormones involved in stress response, in particular, cortisol present at lower levels and both norepinephrine and epinephrine are present at higher levels. Evidence suggests that the control point for this is the amygdala, more specifically the region of the basolateral nucleus. The magnitude of how an experience is remembered is effected by the emotional state of the individual.