[Functional brain mapping of pain perception]

Area of Science:

• Neuroscience
• Pain Research
• Functional Neuroimaging

Background:

• Early pain research focused on the somatosensory cortex, thalamus, and anterior cingulate cortex.
• Functional imaging studies have shifted focus to other brain regions involved in pain perception.

Purpose of the Study:

• To review the contribution of functional imaging to understanding human nociception.
• To highlight key brain areas involved in pain processing and pain relief.

Main Methods:

• Review of functional imaging studies (e.g., fMRI, PET) and intracerebral recordings.
• Analysis of brain activation patterns during painful and non-painful stimuli.
• Investigation of brain responses during pain relief.

Main Results:

• The insular and SII cortices (operculo-insular cortex) are consistently activated during pain and correlate with pain intensity.
• Electrical stimulation of the operculo-insular cortex elicits pain.
• These areas show abnormal recruitment in neuropathic pain, suggesting plasticity.
• Medial prefrontal and rostral cingulate areas are associated with pain control and relief.

Conclusions:

• The operculo-insular cortex is a critical hub for sensory and intensity aspects of pain processing.
• Plastic changes in pain-processing areas may occur in neuropathic pain.
• Specific medial brain regions are involved in modulating pain perception and facilitating pain relief, potentially via endogenous opioid pathways.