Neurobiological Impacts of Trauma Flashcards

Which brain structure is primarily responsible for processing and storing fear memories associated with traumatic experiences?

Answer: Amygdala

The amygdala is the brain's fear-processing center and is hyperactivated during and after trauma, encoding emotionally charged memories with heightened intensity.

The hypothalamic-pituitary-adrenal (HPA) axis is primarily responsible for regulating which aspect of the trauma stress response?

Answer: Cortisol and stress hormone release

The HPA axis governs the release of cortisol and other glucocorticoids, which mobilize the body's resources during a stress response and can be dysregulated in chronic trauma exposure.

During an acute trauma response, which branch of the autonomic nervous system is first activated to initiate the fight-or-flight reaction?

Answer: Sympathetic nervous system

The sympathetic nervous system is rapidly activated during perceived threat, triggering release of catecholamines and mobilizing physiological resources for survival.

Which neurotransmitter is most directly associated with the hyperarousal and fight-or-flight response triggered by trauma exposure?

Answer: Norepinephrine

Norepinephrine (noradrenaline) is the primary catecholamine driving sympathetic activation during trauma, and its dysregulation is central to PTSD hyperarousal symptoms.

Research consistently shows that chronic trauma and prolonged cortisol elevation result in what structural change to the hippocampus?

Answer: Decreased volume due to glucocorticoid neurotoxicity

Elevated glucocorticoids from chronic stress cause dendritic atrophy and impaired neurogenesis in the hippocampus, resulting in measurable volume reduction observed in PTSD neuroimaging studies.

The 'freeze' or tonic immobility response to overwhelming trauma is primarily mediated by which nervous system mechanism?

Answer: Sympathetic activation co-occurring with parasympathetic activation

The freeze response involves simultaneous high sympathetic arousal (internal activation) combined with dorsal vagal parasympathetic braking, creating a state of immobility despite internal hyperactivation.

Decreased activity in the medial prefrontal cortex during trauma flashbacks primarily impairs which function?

Answer: Rational appraisal and emotional modulation of the amygdala

The medial prefrontal cortex normally inhibits amygdala reactivity; its decreased activity during flashbacks removes this regulatory brake, allowing fear responses to dominate without rational appraisal.