Cingulate-mediated approaches to treating chronic pain

Area of Science:

• Neuroscience
• Pain Research

Background:

• The anterior midcingulate cortex (aMCC) has been a primary focus in acute pain research.
• Initially thought to encode pain intensity, this function is now attributed to other brain regions like the SII and insular cortices.

Purpose of the Study:

• To explore the evolving understanding of the anterior cingulate cortex (ACC) roles in pain processing.
• To investigate the ACC's involvement in attention, arousal, motor responses, pain modulation, and endogenous pain control.
• To examine the potential of the ACC, particularly its perigenual subdivision, for neurosurgical interventions in intractable pain.

Main Methods:

• Review of functional imaging studies on acute pain.
• Analysis of quantitative imaging data on opioid receptor density in the ACC.
• Consideration of neuroanatomical connections, including the ACC to the periaqueductal gray (PAG).

Main Results:

• The ACC is implicated in pain-related attention, arousal, motor withdrawal, and pain modulation.
• Opioid receptors are densely located in the ACC, suggesting a role in top-down pain control and placebo effects.
• The posterior cingulate cortex shows altered activity during pain, potentially modulating conscious pain experience.

Conclusions:

• The ACC's functions in pain extend beyond intensity encoding to include attentional and modulatory roles.
• The ACC's opioid receptor density and connectivity support its role in endogenous pain control and placebo effects.
• The ACC presents a potential target for future neurosurgical treatments for intractable pain.