'Pain paradox' discovery provides route to new pain control drugs
The discovery could explain the repeated -- and costly -- failure over the last 20 years of clinical trials of potential pain-killing drugs that targeted the substance, known as 'Substance P'. Substance P is produced in both the central nervous system (CNS) -- the brain and spinal cord -- and in our peripheral nervous system (PNS) -- all the other nerves and nerve cells that send signals to the brain. The new research, by the Hebei Medical University in China and the University of Leeds in the UK, has found that, in the peripheral nervous system, Substance P makes nerve cells less responsive and excitable, thereby reducing sensations of pain. This is in direct contrast to its role in the central nervous system, where it triggers very different signals, exciting neurons and so promoting pain. Lead researcher Professor Nikita Gamper, from the University of Leeds, explains: "We were really surprised by the results -- Substance P is described in the literature as a mol...