Chronic back pain may be linked to the growth of nerve fibers.
Researchers from the Johns Hopkins University School of Medicine have found that chronic back pain associated with spinal degeneration may be linked to the growth of sensitive nerve fibers into damaged areas of the vertebrae, where they normally should not be. The results of the study were published in the journal Bone Research (BR).
In experiments on mice, the researchers demonstrated that with aging, lumbar instability, and other forms of spinal degeneration, the condition of the vertebral endplates—thin structures between bone tissue and intervertebral discs—deteriorates. These areas become more porous, and nerve endings associated with pain begin to infiltrate them. This abnormal nerve growth, according to the authors, may sustain chronic pain syndrome.
A key role in this process, it turns out, is played by the protein Slit3, which is produced by osteoblasts—cells that form bone tissue. Under the influence of parathyroid hormone (PTH), its level increased, while nerve fibers in the damaged areas decreased. Against this background, the structure of the vertebrae improved in the mice, and their sensitivity to pain decreased: the animals tolerated pressure better, withstood thermal stimuli longer, and were more active.
The authors emphasize that the results have only been obtained in animals so far; however, the work shows a new potential approach to treating back pain.
