[Pain modulating systems and manual medicine].

Pain can be modulated on several different levels of the nociceptive system. Starting with the primary nociceptive afferents, which can be sensitized and desensitized, a major part of the nociceptive control takes place on the spinal level, where the information is modulated through interneurons with excitatory and inhibitory neurotransmitters, before it is forwarded via projection neurons to the thalamus and different brain stem nuclei. Endogenous opioids play hereby an important role. The activity of the spinal neurons is, in turn, influenced by descending excitatory and inhibitory pathways from brainstem nuclei like the periaqueductal grey matter, the locus coeruleus and the rostral ventromedial medulla. Finally, these nuclei receive descending cortical information from prefrontal and limbic areas as well as the hypothalamus, which is accordingly associated with cognitive, emotional and autonomic functions of pain control. Virtually all therapeutic interventions for pain reduction, including therapeutic procedures in manual medicine, are based on the endogenous functions of these pain modulating systems.