Describe the descending pathways for the control of pain, and discuss the implications of this structural organization for the management of chronic pain.

Question

What will be an ideal response?

Answer 1

Descending control from the brain has a dramatic influence on our perception of pain. Many higher-level brain structures form connections with the PAG of the midbrain, which also receives ascending pain signals. The convergence of descending control and ascending pain information in the PAG provides an opportunity for the modification of incoming pain messages by higher-level cognitive processes. Electrical stimulation of the PAG generally produces a significant reduction in pain. In addition, the PAG contains large numbers of opioid receptors, which interact with opioids such as morphine. The pain relief achieved through the use of opioids probably occurs in large part due to the drugs' actions in the PAG. Researchers have suggested that chronic pain is more of a memory problem than a sensory problem, as if the brain has difficulty forgetting about the pain. Given what is known about descending pathways, chronic pain might be relieved with behavioral and/or cognitive therapy that would increase descending control and activity of the PAG.