Abstract: A cybernetic view on wind-up
March 28, 2006
Med Hypotheses. 2006 Mar 21; [Epub ahead of print]
Farajidavar A, Gharibzadeh S, Towhidkhah F, Saeb S.
Neuromuscular Systems Laboratory, Faculty of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Somayyeh, Hafez, Tehran 15875 4413, Iran.
Wind-up is described traditionally as a frequency dependent increase in the excitability of spinal cord neurons, evoked by electrical stimulation of afferent C-fibers. Different kinds of wind-up have been reported, but wind-up of Abeta fibers in hyperalgesic states has gained little attention.
In this paper, we present a cybernetic view on Abeta fiber wind-up and consider the involved molecular mechanisms as feedback and feedforward processes. Furthermore, our previous hypothesis, the sprouting phenomenon, is included in this view.
Considering the proposed model, wind-up in hyperalgesic states might leave out in three different ways: (1) blocking the NMDA receptors by increasing extracellular Mg(2+), 2) blocking the receptors and channels that contribute to Ca(2+) inward current, and 3) blocking the Abeta fibers by local anesthetics. It seems that wind-up may be inhibited more effectively by using these three blocking mechanisms simultaneously, because in this case, the feedback process (main controller), the feedforward process (trigger), and Abeta stimulation (trigger) would be inhibited concurrently.
Wind up may aggravate the pain in clinical hyperalgesic situations such as post-surgical states, some neuropathic pains, fibromyalgia syndrome, and post-herpetic neuralgia. Surely, clinical studies are needed to validate the effectiveness of our abovementioned suggestions in relieving such clinical pains.
PMID: 16563645 [PubMed - as supplied by publisher]