Spinal cord stimulation modulates supraspinal centers of the descending antinociceptive system in rats with unilateral spinal nerve injury

Spinal cord stimulation (SCS) is a common method for managing chronic pain. This study investigates how SCS affects the brain's pain control pathways, specifically the serotonergic and noradrenergic systems. The researchers examined the dorsal raphe nucleus (DRN) and locus coeruleus (LC), key areas in these pathways, in rats with nerve damage. They looked at the activity of neurons and the production of neurotransmitters involved in pain relief. The study found that SCS activates the serotonergic pathway, potentially reducing pain. The noradrenergic pathway may also contribute, but its role appears to be less significant.

• 1
  SCS increased the number of serotonergic neurons and activated them in the DRN, suggesting a key role for this area in SCS-induced pain relief.
• 2
  While SCS did not activate noradrenergic neurons in the LC, it did restore the balance of DβH expression, an enzyme involved in norepinephrine production, suggesting a modulatory effect.
• 3
  SCS-induced pain relief appears to be primarily mediated by the activation of brain centers in the descending antinociceptive system, rather than by increased local production of serotonin or norepinephrine in the spinal cord.