The chronic pain condition can present in various forms and follow different patterns. For example, in one of the most common, diabetic neuropathy, nerve damage occurs in an ascending pattern. Pain and numbness often are felt symmetrically in both feet followed by a gradual progression up both legs.
The new discovery surrounds the activity of a part of the brain called the anterior cingulate cortex (ACC), thought to be the region most consistently involved in pain processing.
Senior author Philippe Séguéla, a professor in the department of neurology and neurosurgery, and colleagues discovered new information about a type of channel that controls the transmission of pain signals to the ACC.
From lab tests on rats, they found that blocking these channels - called hyperpolarization-activated cyclic nucleotide-gated (HCN) channels - reduced over-stimulation of the ACC and dramatically decreased feelings of pain.
"Our study has revealed one important mechanism linking chronic pain to abnormal activity of the ACC and it provides a cellular and molecular explanation for the overstimulation of neurons in the prefrontal cortex," says Prof. Séguéla. "This gives us new perspectives on therapeutic strategies that could target the HCN channels to help relieve chronic pain."
More recently, using brain scans of the prefrontal regions of the brain, researchers have also discovered that emotional, psychological and cognitive factors can influence pain perception in neuropathic pain.