A new study from researchers at the University of Texas Arlington (TX, USA) has demonstrated that electrical stimulation of midbrain structures leads to reduced nociceptive signaling in the spinal cord of rats, indicating a possible new direction for the treatment of chronic pain.
Current treatment options for chronic pain center on opioid prescription. However, concern over the rates of opioid addiction and overdose has led to an increased demand for new treatment options. This new study, published in Experimental Brain Research recently, investigated electrical stimulation of midbrain structures involved in pain regulatory pathways as an alternative treatment option for chronic pain.
The team stimulated the ventral tegmental area (VTA), which has previously been implicated in reward pathways and nociceptive modulation. They used a custom-designed wireless device to demonstrate that VTA stimulation reduced pain sensation.
“Until this study, the VTA of the brain was studied more for its key role in positive reinforcement, reward and drug abuse,” commented group leader Yuan Bo Peng (University of Texas Arlington). “We have now confirmed that stimulation of this area of the brain can also be an analgesic tool.”
VTA stimulation was also observed to block pain at the spinal cord level. Stimulation was demonstrated to significantly inhibit dorsal horn neuronal activity in response to nociceptive stimulation, indicating that VTA stimulation may exert its analgesic effects via descending modulatory pain pathways.
Additionally, the process triggered the release of dopamine, which researchers suggest could reduce the emotional distress associated with chronic pain.
There is hope that deep brain stimulation could become a more common treatment option for chronic pain, with the major benefit over opioid prescription drugs being the alleviation of pain without the side effects associated with medication.
“This is the first study to use a wireless electrical device to alleviate pain by directly stimulating the VTA of the brain,” added Peng. “While still under laboratory testing, this new method does provide hope that in the future we will be able to alleviate chronic pain without the side effects of medications.”
Sources: University of Texas press release; Li A-L, Sibi J, Yang X, Chiao J-C, Peng Y. Stimulation of the ventral tegmental area increased nociceptive thresholds and decreased spinal dorsal horn neuronal activity in rat. Experimental Brain Research. DOI: 10.1007/s00221-016-4558-z (2016).