The Brain Stress Systems I: The Implicit Level of Brain Operations

Abstract

In this chapter we continue our exploration of the neurobiology of functional somatic symptoms by considering the role of the brain. The brain plays a key role in regulation, in coordinating the stress response, and in helping the child adapt to the circumstances of living over time. Every component of the body stress system-the HPA axis, autonomic nervous system, and immune-inflammatory system-is regulated by the brain or connected to it, or communicating with it, in some way. When a child is exposed to stress that is chronic, uncontrollable, unpredictable, cumulative, recurrent, or overwhelming, it leads to activation of brain systems that are involved in managing stress and in stress-related adaptations. Because these regions interact with and modulate motor-, sensory-, pain-, and fatigue-processing regions, the sustained activation of the brain stress systems changes patterns of neural activation and connectivity across and between these systems, and sets up the necessary conditions for generating functional 11 The Brain Stress Systems I: The Implicit Level of Brain Operations