Scientific Reports, 2019 · DOI: 10.1038/s41598-019-54072-7 · Published: December 19, 2019
The study investigates the relationship between cardiovascular responses (blood pressure and heart rate) and the activation of nociceptive afferents (nerve fibers that transmit pain signals) in rats. Electrical stimulation was applied to dorsal cutaneous nerves (DCNs) at different spinal levels and frequencies to activate different types of nerve fibers (A-fibers and C-fibers). The study found that different types of nerve fibers contribute to different cardiovascular responses, with A-fibers primarily affecting heart rate and C-fibers primarily affecting blood pressure.
The study suggests that pathological autonomic reflexes, such as autonomic dysreflexia after spinal cord injury, may show differential dependence on A-fiber and C-fiber sensory afferent inputs, providing insights into the mechanisms underlying this condition.
The findings could inform the development of targeted therapies for managing cardiovascular responses in conditions involving nociceptive input, by selectively modulating A-fiber and C-fiber activity.
The study highlights the importance of considering both blood pressure and heart rate when assessing cardiovascular responses to nociceptive input, potentially leading to more refined methods for pain measurement in animal models.