Controllability Circuit
Established mechanism (Maier & Seligman 2016): The vmPFC detects the dimension of controllability. When stressors are controllable, the vmPFC sends excitatory glutamatergic projections to inhibitory GABAergic interneurons in the DRN, which suppress 5-HT neurons. This prevents the stress response cascade. When stressors are uncontrollable, the vmPFC fails to inhibit the DRN, and unchecked 5-HT release drives the behavioral consequences (passivity, anxiety, exaggerated fear).
Critical features
- Detection circuit involves bidirectional flow between dorsomedial striatum (DMS) and prelimbic cortex
- Action circuit consists of neurons projecting from PL to DRN
- Controllability detection is computationally specific -- identical formalism to instrumental contingency (conditional probability of outcome given response != conditional probability of outcome absent response)
- Prior experience with behavioral control provides PROACTIVE resilience -- vmPFC activation from prior controllable experience protects against later uncontrollable stress (Amat et al. 2006)
Architectural implication
The controllability provision actuator has a specific neural target. Providing structured experiences where the human detects action-consequence contingency activates the vmPFC-DRN pathway. This is the mechanism by which the stabilizer could restore capacity.
Source verification
Maier & Seligman 2016 ("Learned Helplessness at Fifty") -- verified. Figures 2, 4, and 5 schematically depict vmPFC-DRN interactions.