The significance of A‐δ and C fibres for the perception of synthetic heat

European Journal of Pain - Tập 7 - Trang 63-71 - 2003
Heinrich Fruhstorfer1, Eva-Liz Harju2,3, Ulf F Lindblom4
1Institute of Physiology, University of Marburg, Marburg/Lahn D-35033, Germany
2Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden
3Department of Psychology, Gösta Ekman Laboratory for Sensory Research, Stockholm University, Stockholm, Sweden
4Department of Clinical Neurosciences, Section of Neurology, Karolinska Institute, Stockholm, Sweden

Tóm tắt

AbstractSynthetic heat is a perception of strong, but not painful, heat arising when skin is stimulated by an alternating pattern of adjacent cold and warmth. This study examines the contribution of different classes of nerve fibres to this perception. In 40 subjects changes in synthetic heat and thermal perceptions were studied during a 30‐min ischaemic nerve block in one reaction time, and one threshold determination task. Synthetic heat stimuli were described as hot or warm, but not as painful, and were preceded by a transient cold. Reaction times for synthetic heat stimuli did not differ from those for cold stimuli. Thresholds for synthetic heat and thermal stimuli were similar. During A fibre nerve block the perception of synthetic heat lost the cold component whereas the frequency of hot and warm descriptors did not change. The perception of cold stimuli changed, such that pure cold was replaced by dysaesthetic descriptors. Reaction times and thresholds for thermal and synthetic heat stimuli increased equally during the nerve block. It is concluded that the perception of synthetic heat most likely arises from the fusion of signals dependent on unmyelinated low threshold cold and warm receptors. It is not dependent on A‐δ cold fibres, and a contribution of nociceptors is quite unlikely. The possibility of a psychological contribution at the perceptual level is discussed.

Tài liệu tham khảo

10.1093/mind/VII.25.141 10.2307/1413541 Berglund B, 1997, Progress in Pain Research and Management, 435 Berglund B, 1999, Fechner Day ‘99: The End of 20th Century Psychophysics, 130 10.2307/1415010 10.1111/j.1469-7793.2001.t01-1-00855.x 10.1113/jphysiol.1996.sp021789 10.1126/science.280.5364.747 10.1126/science.8023144 10.1038/384258a0 10.2307/1413971 Damasio A.R., 1999, The Feeling of What Happens: Body and Emotion in the Making of Consciousness 10.1152/jn.2000.83.6.3575 10.2307/1414421 10.1136/jnnp.51.9.1164 10.1037/h0036331 10.1016/B978-0-08-021208-1.50030-8 10.1016/0304-3959(84)90112-X 10.1007/BF00587919 10.1136/jnnp.39.11.1071 10.1007/BF00587918 10.3758/BF03199698 Gregory R.L., 1993, Odd Perceptions 10.2307/1414686 10.1136/jnnp.54.6.527 Harju E.‐L, 2000, Fechner Day 2000, 203 Heller M.A., 1991, The Psychology of Touch, 115 Hensel H, 1966, Touch, Heat and Pain, 275 Hensel H, 1981, Thermoreception and Temperature Regulation, Monographs of the Physiological Society No. 38 10.1113/jphysiol.1960.sp006522 10.1037/h0063331 Katz D, 1989, The world of touch, 1 10.1016/S0304-3959(00)00295-5 10.1016/0304-3959(75)90044-5 10.1126/science.288.5472.1835 10.1037/h0075191 10.1093/brain/122.2.239 Thunberg T, 1896, Förnimmelserna vid till samma ställe lokaliserad, samtidigt pågående köld‐ och värmeretning (the perceptions of simultaneous cold‐ and warm stimulations, localized to the same skin area), Uppsala Läkarfören Förh, 2, 489 10.1113/jphysiol.1995.sp020767 10.1152/jn.1984.51.2.325 10.1016/0304-3959(89)90218-2 Weber E.H., 1996, E.H. Weber on the Tactile Senses 10.1037/0033-2909.88.3.638 10.1093/brain/113.4.893 10.1093/brain/114.2.907 10.1093/brain/114.4.1819 10.1002/mus.880180714
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European Journal of Pain

Tập 7

63-71

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