Excessive pain due to brain central sensitization has been called a “software malfunction”. Part of that appears to be of Dopa/GABA circuits.
Arthritis Rheumatol. 2014 Jan;66(1):203-12.
Disrupted brain circuitry for pain-related reward/punishment in fibromyalgia.
Loggia ML, Berna C, Kim J, Cahalan CM, Gollub RL, Wasan AD, Harris RE, Edwards
RR, Napadow V.
http://www.ncbi.nlm.nih.gov/pubmed/24449585
- Used Fibromyalgia subjects
- Inflated blood pressure cuff for pain
- monitored MRI
- normally would see anticipation of pain and anticipation of relief in brain function
- “activity in the ventral tegmental area during periods of pain and periods of anticipation (of both pain and relief) was dramatically reduced or abolished.”
- CONCLUSION:”FM patients exhibit disrupted brain responses to reward/punishment. The ventral tegmental area is a source of reward-linked dopaminergic/γ-aminobutyric acid-releasing (GABAergic) neurotransmission in the brain, and our observations are compatible with reports of altered dopaminergic/GABAergic neurotransmission in FM. Reduced reward/punishment signaling in FM may be related to the augmented central processing of pain and reduced efficacy of opioid treatments in these patients.”
Comment – recent MRI imaging has found continual activation of nucleus acumens (pleasure centre) in chronic pain (Apkarian). I imagine it makes pleasure center inoperable and becomes part of the software malfunction in chronic pain…