Aktivierung axoaxonischer Synapsen durch Salven in afferenten C-Fasern: Manfred Zimmermanns Falsifizierung der Gate-Control-Theorie

[Physiology of pain]

Pain research is based broadly on physiological disciplines and its development follows the methodological progress of the era, from classical psychophysiology to electrophysiological investigations at peripheral and central nociceptive systems, single cells and ion channels to modern imaging of nociceptive processing. Physiological pain research in Germany has long been part of an interdisciplinary research network extending beyond all political boundaries, and this situation has continued since molecular techniques started to dominate all biomedical research. Current scientific questions, such as intracellular nociceptive signal mechanisms, interactions with other physiological systems including the immune system, or the genetic basis of epidemic and chronic pain diseases can only be solved interdisciplinary and with international collaboration.

Effects of menthol and cold on histamine-induced itch and skin reactions in man

The effects of cooling and topical application of menthol on histamine-induced itch, wheal and flare reactions of the left lower arm were investigated in a threefold cross-over design with 15 healthy male volunteers. Lowering skin temperature by cooling from 32.8 +/- 0.3 degrees C to 29.7 +/- 0.5 degrees C reduced itch intensity from 260 +/- 47 units to 55 +/- 12 units (visual analogue scale) and flare diameters from 39.0 +/- 2.0 mm to 30.2 +/- 1.8 mm; wheal reactions were not affected. A similar reduction in itch was found under menthol (42 +/- 14 units) although skin temperature was not decreased. These findings suggest a central inhibitory effect of cold sensitive A-delta fibre activation on itch.