Life sciences, dACC, vACC, Anterior insula, OFC, Lateral habenula, VTA, DRN, Depression, Anxiety, Mood disorders, Addiction, Motivation, Impulsivity, Active avoidance, Amygdala, Ventral striatum, Affective cortico-striato-thalamo-cortical loop, Decision making, Value-based learning, Goal-directed control of behaviour, Well-being, Dopamine, Serotonin, Reward-processing circuit, Adversity-processing circuit, Inhibitory avoidance, Inhibitory self-control
We propose that dorsal anterior cingulate cortex (dACC) and anterior insula (AI) project to lateral habenula (LHb) and D2 loop of ventral striatum (VS). They form functional adversity processing circuit directed toward inhibitory avoidance and self-control. This circuit learns what is bad or harmful to us, evaluates and predicts risks - to stop us from selecting and going/moving for the bad or suboptimal choices that decrease our well-being and survival chances.
Proposed role of dACC is to generate a WARNING signal when things are going (or might end) bad or wrong, to prevent negative consequences: pain, harm, loss or failure. The AI signals about bad, low, noxious and aversive qualities, which might make us sick or cause discomfort. These cortical adversity processing regions activate directly and indirectly (via D2 loop of VS) the LHb, which then inhibits dopamine and serotonin release (and is reciprocally inhibited by VTA/SNc, DRN and MRN) to avoid choosing and doing things leading to harm or loss. Overstimulation of this circuit makes us feel worse, even down. We propose that dopamine attenuates output of the adversity processing circuit, thus decreasing inhibitory avoidance and self-control, while serotonin attenuates dACC, AI, clOFC, D1 loop of VS, LHb, amygdala and pain pathway.
Thus, by reciprocal inhibition, by causing dopamine and serotonin suppression - and by being suppressed by them, the adversity processing circuit competes with reward processing circuit for control of choice behavior and affective states. We propose stimulating effect of dopamine and calming inhibitory effect of serotonin on the active avoidance circuit involving amygdala, linked to threat processing, anger, fear, self-defense and violence. We described causes and roles of dopamine and serotonin signaling in health and in mental dysfunctions. We made new idea that ventral ACC activation signals well-being /that we are doing well/, and that vACC attenuates dACC and stimulates serotonergic dorsal raphe nucleus /DRN/, when we gain/reach safety, comfort, valuable resources (social or biological rewards), affection and achieve goals.