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Brief Neuroscience of Trauma

  • Writer: Katherine Mackenzie
    Katherine Mackenzie
  • Feb 4
  • 4 min read

Updated: Apr 18

The brain is a complex organ with many interconnected regions, each playing a specific role our daily functioning.


Trauma can physically alter our neural connectivity and the way our brain develops. These types of neurological disruptions may exmplain some of the ongoing symptoms of PTSD and how they can impact someone's capacity to manage daily activities. Here's a breakdown of several significant brain regions:




Brainstem & Midbrain



The brain stem is in the lowest part of the brain and is made up of the midbrain, pons, and medulla oblongata.


It controls many vital functions, such as breathing, heart rate, and blood pressure, and the nerves and muscles used in seeing, hearing, walking, talking, and eating.



The midbrain is the topmost part of the brainstem, serving as a relay station for sensory and motor pathways, particularly for reflexes related to vision, hearing and alertness.


Below are a few of the most significant parts of the Brainstem and Midbrain region that are involved in our brain's response to trauma:





Superior Colliculus:

  • Location: Located in the midbrain. 

  • Function: Primarily involved in visual processing and eye movements, but also plays a role in orienting attention to potential threats. 

  • Role in trauma: It receives information from the retina and helps to direct gaze towards visually salient stimuli and may contribute to rapid detection and response to visually salient stimuli associated with danger. 





Locus Coeruleus:

  • Location: Situated in the brainstem. 

  • Function: Considered the "stress center" of the brain, producing norepinephrine, a neurotransmitter crucial for arousal, vigilance, and the "fight-or-flight" response. 

  • Role in trauma: High activation of the locus coeruleus during traumatic events can lead to increased anxiety, heightened alertness, and physical symptoms like rapid heart rate and sweating. 





Periaqueductal Gray (PAG):

  • Location: Located around the cerebral aqueduct in the midbrain. 

  • Function: Plays a key role in pain modulation, defensive behaviors, and autonomic nervous system regulation. 

  • Role in trauma: Crucial for pain processing and modulating defensive behaviors like fear and aggression that are involved the "fight-or-flight" response and potentially contributing to the development of chronic pain and anxiety following trauma. 



 Temporal Lobe





The temporal lobe is located on the sides of the head, near the temples and ears. It plays a crucial role in processing auditory information, understanding language, and managing emotions. It's also involved in recognizing faces, and forming both visual and verbal memories.




Below are the most significant parts of the Temporal Lobe region that are involved in our brain's response to trauma:




Amygdalae:

  • Location: Found within the temporal lobe (there is one in each cerebral hemisphere

  • Function: Primarily responsible for processing emotions, particularly fear and forming emotional memories. 

  • Role in trauma: This region, part of the limbic system, is essential for processing emotions, especially fear and pleasure. It plays a role in memory consolidation and social behavior and is crucial for storing traumatic memories and associating them with strong emotional responses. 





Hippocampi:

  • Location: Located in the medial temporal lobe (there is one in each cerebral hemisphere

  • Function: Important for forming new memories and spatial navigation. 

  • Role in trauma: It is considered a key part of the limbic system, the part of the brain involved in our behavioural and emotional responses in survival. Potential impairments in hippocampal function can contribute to memory disruptions and flashbacks associated with trauma. 





Prefrontal Cortex



The prefrontal cortex is the section of the frontal cortex that lies at the very front of the brain.


It is involved in many functions but is best known for its role in executive functioning.


These functions focus on controlling reflexive behaviours to enable longer-term actions such as planning, decision-making, problem-solving, self-control, and acting with long-term goals in mind.


Trauma can significantly impair executive functions leading to difficulties with emotional regulation, impaired judgment, and a reduced ability to cope with stress. 




Autonomic Nervous System




The Autonomic Nervous System is part of the peripheral nervous system and is responsible for controlling involuntary bodily functions like heart rate, breathing, and digestion.


It is regulated by the brain, particularly the hypothalamus. The autonomic nervous system can be highly activated during traumatic events, leading to physiological changes that support the "fight-or-flight" response. You can learn more about the impact of trauma on the nervous system here.




Key points to remember


  • These brain regions are interconnected and work together to process and respond to traumatic experiences. 


  • Trauma can lead to structural and functional changes in these brain areas, contributing to long-term effects like post-traumatic stress disorder (PTSD). 


  • Treatment approaches for trauma often target modulating the activity of these brain regions to promote healing and recovery. 




References:





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