According to a recent study, researchers suggest that the body’s increased expression of pituitary adenylate cyclase activating polypeptide (PACAP)—a peptide neurotransmitter the body releases in response to stress—is also increased in response to neuropathic pain, and contributes to the pain symptoms.
In the study, researchers from the University of Vermont examined the expression of PACAP along the spino-parabra-chiomygdaloid tract, one of the nervous system’s pathways to the brain. This pathway travels from the spinal cord to the amygdala, which is considered the brain’s home base for emotional behavior.
Using models for chronic pain and anxiety, as well as models that can trace PACAP neurocircuits, the team members were able to observe where the stress and chronic pain pathways intersected, explains a media release from the University of Vermont.
“Chronic pain and anxiety-related disorders frequently go hand-in-hand,” says senior author Victor May, PhD, professor of neurological sciences at the University of Vermont (UVM), in the release.
The scientists note in the release that, while they saw an increase in anxiety-related behaviors in models of chronic pain, the anxious behavior and pain hypersensitivity were significantly reduced when a PACAP receptor antagonist—designed to block the response—was applied.
“By targeting this regulator and pathway, we have opportunities to block both chronic pain and anxiety disorders,” says May, in the release.
“This would be a completely different approach to using benzodiazepine and opioids—it’s another tool in the arsenal to battle chronic pain and stress-related behavioral disorders,” he adds.
The study was published recently in Biological Psychiatry.
[Source(s): University of Vermont, Science Daily]