Neurobiology of chronic pain and comorbid mental health disorders - From single cells to networks to behaviour

Chronic pain is a complex multidimensional sensory and emotional/affective experience with multifaceted behavioral manifestations. From our preclinical work on the anterior cingulate cortex (ACC), a brain region important for pain processing, I will motivate the following conclusions:

1. There are no pain-specific neurons in the ACC. Pain is rather encoded on the population level.
2. Chronic pain leads to a disturbance of the ACC network, which then misinterprets sensory stimuli as nociceptive.
3. This misinterpretation can be normalized by common analgesic drugs, yet analgesia represents a new brain state.
4. Approach-avoidance behavior, which is comorbid in chronic pain depends on neuronal plasticity at synapses from the amygdala to the ACC.
5. A new technical approach for the tracking of behavior reveals specific neuronal dynamics during pain epochs. These findings shed new light on the circuit mechanisms of chronic pain and the effects of analgesia in the neocortex.