2: Neurobiology of trauma responses

2: Neurobiology of Trauma Responses

When something traumatic happens, it’s not just an emotional experience – your brain and body undergo significant biological changes. Understanding this "neurobiology" helps explain why trauma feels so overwhelming and why reactions like fear or panic can feel automatic.

Imagine your brain has a built-in alarm system, primarily centered in a tiny, almond-shaped region called the amygdala. Its job is lightning-fast: scan everything for danger. During trauma, the amygdala goes into overdrive, shouting "THREAT!" the moment it senses anything resembling the original danger (a sound, smell, or situation). This triggers your body’s survival response – fight, flight, freeze, or fawn – before you’ve even had a conscious thought.

Meanwhile, another key area, the hippocampus, struggles. Normally, the hippocampus acts like a librarian, filing memories with context (time, place, details). Under extreme stress, this function gets disrupted. Trauma memories might be stored as fragmented sensory flashes (images, sounds, smells) without the full story or a sense of being "in the past." This is why a trigger can suddenly make the trauma feel like it’s happening right now – the memory isn’t properly filed away as a completed event.

The prefrontal cortex, your brain’s rational "thinking center" (responsible for planning, reasoning, and calming emotions), often gets temporarily sidelined during trauma. When the amygdala screams, the prefrontal cortex gets less energy and can’t effectively say, "Wait, this is just a reminder, the actual danger is over." This "hijacking" makes it incredibly hard to think clearly or feel safe when triggered.

Fuelling these brain changes is the HPA axis (Hypothalamic-Pituitary-Adrenal axis). This is your body’s central stress response system. When the amygdala detects threat, it signals the hypothalamus, which tells the pituitary gland, which then instructs the adrenal glands to pump out stress hormones like cortisol and adrenaline. These hormones surge through your body, causing physical reactions: heart pounding, muscles tensing, breathing speeding up – preparing you for survival action. After trauma, this system can become hypersensitive, reacting intensely to minor stressors and taking longer to calm down, leading to constant feelings of being on edge.