Thursday, April 15, 2010

Emotional Trauma in Review - Part 2

C - The Neurobiology of Stress
According to Herman (1992), “[t]he ordinary response to danger is a complex, integrated system of reactions, encompassing both body and mind. Threat initially arouses the sympathetic nervous system, causing the person in danger to feel an adrenalin rush and go into a state of alert. [Adrenalin] also concentrates a person’s attention on the immediate situation. In addition, threat may alter ordinary perceptions: people in danger are often able to disregard hunger, fatigue, or pain. Finally, threat evokes intense feelings of fear and anger. These changes in arousal, attention, perception, and emotion are normal, adaptive [stress] reactions. They mobilize the threatened person for strenuous action either in battle or in flight.”
In what follows I mean to update our understanding of the physiological stress which undergirds our acute adaptive responses to danger, and which becomes severely disrupted in the process of prolonged emotional trauma, a dysregulation which itself triggers stress, thus compounding the physiological and psychological burden, the suffering.

Different stressors require different responses
From: Joels, M. & Baram, T.Z. (2009).

The ability to change neuronal activity (and hence behavior and cognition) both rapidly and enduringly in response to threatening challenges is crucial for survival and has thus resulted in a highly coordinated, complex and evolutionarily conserved stress-response system.
Because different challenges require distinct responses (for example, social decisions or flight) that involve different sets of neuronal populations acting in concert or sequentially, the brain has evolved a system that can produce such diverse alterations in neuronal activity.
This system consists of the stress mediators shown above, which not only occupy characteristic niches of time, space and function, but also are exquisitely coordinated at multiple levels to create an orchestrated stress-response symphony.
This ‘stress neuro-symphony’ provides the capacity to generate precise, focused alterations in neuronal activity in response to stress signals. These alterations can range spatially from individual synapses up to the whole individual, and temporally from milliseconds to days.

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