Targeted inactivation of spinal α2 adrenoceptors promotes paradoxical anti-nociception

The study investigates how noradrenaline, a chemical messenger in the brain and spinal cord, affects pain. It specifically looks at α2 receptors, which are usually thought to reduce pain when activated. Surprisingly, the researchers found that blocking these α2 receptors in the spinal cord can also reduce pain. This was observed even when the spinal cord was damaged, and the effect was stronger when the drug was applied directly to the spinal cord. This suggests that the way we currently understand how noradrenaline controls pain in the spinal cord may need to be revised. The findings challenge the idea that activating spinal α2 receptors is always anti-nociceptive.

• 1
  Targeted blockade of spinal α2 adrenoceptors can reduce spinal nociceptive transmission in vivo.
• 2
  The anti-nociceptive effect persisted below a chronic spinal cord injury, indicating the effect is primarily spinal rather than supraspinal.
• 3
  The anti-nociceptive effect was observed throughout sensory-dominant, sensorimotor integrative, and motor-dominant regions of the spinal gray matter.