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A thermoreceptor is a sensory receptor, or more accurately the receptive portion of a sensory neuron, that codes absolute and relative changes in temperature, primarily within the innocuous range. In the mammalian peripheral nervous system warmth receptors are thought to be unmyelinated C-fibres (low conduction velocity), while those responding to cold have thinly myelinated Aδ axons (faster conduction velocity). The adequate stimulus for a warm receptor is warming, which results in an increase in their action potential discharge rate. Cooling results in a decrease in warm receptor discharge rate. For cold receptors their firing rate increases during cooling and decreases during warming. Some cold receptors also respond with a brief action potential discharge to high temperatures, i.e. typically above 45°C, and this is known as a paradoxical response to heat. The mechanism responsible for this behavior has not been determined. however further research will be put forward.
A special form of thermoreceptor is found in some snakes, the viper pit organ and this specialized structure is sensitive to energy in the infrared part of the spectrum.
In mammals, temperature receptors innervate various tissues including the skin (as cutaneous receptors), cornea and bladder. Neurons from the pre-optic and hypothalamic regions of the brain that respond to small changes in temperature have also been described, providing information on core temperature. The hypothalamus is involved in thermoregulation, the thermoreceptors allowing feed-forward responses to a predicted change in core body temperature in response to changing environmental conditions.
Thermoreceptors have been classically described as having 'free' non-specialised endings; the mechanism of activation in response to temperature changes is not completely understood.
Cold-sensitive thermoreceptors give rise to the sensations of cooling, cold and freshness. In the cornea cold receptors are thought to respond with an increase in firing rate to cooling produced by evaporation of lacrimal fluid 'tears' and thereby to elicit a reflex blink.
Warm and cold receptors play a part in sensing innocuous environmental temperature. Temperatures likely to damage an organism are sensed by sub-categories of nociceptors that may respond to noxious cold, noxious heat or more than one noxious stimulus modality (i.e they are polymodal). The nerve endings of sensory neurons that respond preferentially to cooling are found in moderate density in the skin but also occur in relatively high spatial density in facial skin, cornea, tongue and strangely enough the bladder. The speculation is that lingual cold receptors deliver information that modulates the sense of taste, cold beer tastes pretty good, but cold gravy is not so tasty.
Mechanism of transduction
This area of research has recently received considerable attention with the identification of the Transient Receptor Potential (TRP) family of proteins. The transduction of temperature in cold recceptors is mediated in part by the TRPM8 channel. This channel passes a mixed inward cationic (predominantly carried by Ca2+ ions) current of a magnitude that is inversely proportional to temperature. The channel is sensitive over a temperature range spanning about 10-35°C. Another molecular component of cold transduction is the temperature dependence of so-called leak channels which pass an outward current carried by potassium ions. Some leak channels derive from the family of two-pore (2P) domain potassium channels. Amongst the various members of the 2P-domain channels, some close quite promptly at temperatures less than about 28°C (eg. TRAAK, TREK).
- Baumgartner, U., Cruccu, G., Iannetti, G. D., & Treede, R.-D. (2005). Editorial: Laser guns and hot plates: Pain Vol 116(1-2) Jul 2005, 1-3.
- Benedek, G., Obal, Jr., Jancso-Gabor, A., & Obal, F. (1980). Effects of elevated ambient temperatures on the sleep-waking activity of rats with impaired warm reception: Waking & Sleeping Vol 4(1) Jan-Mar 1980, 87-94.
- Bohm-Starke, N., Hilliges, M., Brodda-Jansen, G., Rylander, E., & Torebjork, E. (2001). Psychophysical evidence of nociceptor sensitization in vulvar vestibulitis syndrome: Pain Vol 94(2) Nov-Dec 2001, 177-183.
- Borovikova, L. V., Borovikov, D. V., Ermishkin, V. V., & Revenko, S. V. (1997). Tonic and stimulus-dependent inhibition of polymodal skin C-unit responses to thermal stimuli by lidocaine and N-propylajmaline in the cat: Sensory Systems Vol 11(2) Apr-Jun 1997, 72-80.
- Bove, M., Mansson, I., & Eliasson, I. (1998). Thermal oral-pharyngeal stimulation and elicitation of swallowing: Acta Oto-Laryngologica Vol 118(5) 1998, 728-731.
- Cahusac, P. M. B., Morris, R., & Hill, R. G. (1995). A pharmacological study of the modulation of neuronal and behavioural nociceptive responses in the rat trigeminal region: Brain Research Vol 700(1-2) Nov 1995, 70-82.
- Casey, K. L. (2006). Laser guns and hot plates revisited: Comment: Pain Vol 120(3) Feb 2006, 326-327.
- Chernigovskiy, V. N. (1967). Thermoreceptors and osmoreceptors. Washington, DC: American Psychological Association.
- Clark, W. C., & Mehl, L. (1973). Signal detection theory procedures are not equivalent when thermal stimuli are judged: Journal of Experimental Psychology Vol 97(2) Feb 1973, 148-153.
- Dawson, N. J., Dickenson, A. H., Hellon, R. F., & Woolf, C. J. (1981). Inhibitory controls on thermal neurones in the spinal trigeminal nucleus of cats and rats: Brain Research Vol 209(2) Mar 1981, 440-445.
- di Bella, L., Tarozzi, G., Rossi, M. T., & Scalera, G. (1981). Effect of liver temperature increase on food intake: Physiology & Behavior Vol 26(1) Jan 1981, 45-51.
- Du, J., Koltzenburg, M., & Carlton, S. M. (2001). Glutamate-induced excitation and sensitization of nociceptors in rat glabrous skin: Pain Vol 89(2-3) Jan 2001, 187-198.
- Dulloo, A. G. (2007). Suppressed thermogenesis as a cause for resistance to slimming and obesity rebound: Adaptation or illusion: International Journal of Obesity Vol 31(2) Feb 2007, 201-203.
- Eide, P. K., Jorum, E., & Stenehjem, A. E. (1996). Somatosensory findings in patients with spinal cord injury and central dysaesthesia pain: Journal of Neurology, Neurosurgery & Psychiatry Vol 60(4) Apr 1996, 411-415.
- Fillingim, R. B., Edwards, R. R., & Powell, T. (1999). The relationship of sex and clinical pain to experimental pain responses: Pain Vol 83(3) Dec 1999, 419-425.
- Fillingim, R. B., Edwards, R. R., & Powell, T. (2000). Sex-dependent effects of reported familial pain history on recent pain complaints and experimental pain responses: Pain Vol 86(1-2) May 2000, 87-94.
- Fruhstorfer, H. (1984). Thermal sensibility changes during ischemic nerve block: Pain Vol 20(4) Dec 1984, 355-361.
- Fruhstorfer, H., & Lindblom, U. (1983). Vascular participation in deep cold pain: Pain Vol 17(3) Nov 1983, 235-241.
- Gall, O., Villanueva, L., Bouhassira, D., & Le Bars, D. (2000). Spatial encoding properties of subnucleus reticularis dorsalis neurons in the rat medulla: Brain Research Vol 873(1) Aug 2000, 131-134.
- Gentle, M. J., & Tilston, V. L. (2000). Nociceptors in the legs of poultry: Implications for potential pain in preslaughter shackling: Animal Welfare Vol 9(3) 2000, 227-236.
- Georgopoulos, A. P. (1976). Functional properties of primary afferent units probably related to pain mechanisms in primate glabrous skin: Journal of Neurophysiology Vol 39(1) Jan 1976, 71-83.
- Granovsky, Y., Matre, D., Sokolik, A., Lorenz, J., & Casey, K. L. (2005). Thermoreceptive innervation of human glabrous and hairy skin: A contact heat evoked potential analysis: Pain Vol 115(3) Jun 2005, 238-247.
- Green, B. G. (1984). Thermal perception on lingual and labial skin: Perception & Psychophysics Vol 36(3) Sep 1984, 209-220.
- Hirata, H. (1983). Responses of cat trigeminal ganglion neurons to thermal stimulation of facial regions: Dissertation Abstracts International.
- Hori, T., & et al. (1982). Responses of preoptic thermosensitive neurons to mediobasal hypothalamic stimulation: Brain Research Bulletin Vol 8(6) Jun 1982, 677-683.
- Hori, T., Kiyohara, T., Oomura, Y., Nishino, H., & et al. (1987). Activity of thermosensitive neurons of monkey preoptic hypothalamus during thermoregulatory operant behavior: Brain Research Bulletin Vol 18(5) May 1987, 649-655.
- Hori, T., Kiyohara, T., Shibata, M., Oomura, Y., & et al. (1986). Responsiveness of monkey preoptic thermosensitive neurons to non-thermal emotional stimuli: Brain Research Bulletin Vol 17(1) Jul 1986, 75-82.
- Kobayashi, S., & Murakami, N. (1982). Thermosensitive neurons in slice preparations of rat medulla oblongata: Brain Research Bulletin Vol 8(6) Jun 1982, 721-726.
- LaMotte, R. H., & Thalhammer, J. G. (1982). Response properties of high-threshold cutaneous cold receptors in the primate: Brain Research Vol 244(2) Jul 1982, 279-287.
- Lavigne, G., Zucconi, M., Castronovo, C., Manzini, C., Marchettini, P., & Smirne, S. (2000). Sleep arousal response to experimental thermal stimulation during sleep in human subjects free of pain and sleep problems: Pain Vol 84(2-3) Feb 2000, 283-290.
- Lee, H., lida, T., Mizuno, A., Suzuki, M., & Caterina, M. J. (2005). Altered Thermal Selection Behavior in Mice Lacking Transient Receptor Potential Vanilloid 4: Journal of Neuroscience Vol 25(5) Feb 2005, 1304-1310.
- Lundy, R. F., & Contreras, R. J. (1995). Tongue adaptation temperature influences lingual nerve responses to thermal and menthol stimulation: Brain Research Vol 676(1) Apr 1995, 169-177.
- Major, G. C., Doucet, E., Trayhurn, P., Astrup, A., & Tremblay, A. (2007). Clinical significance of adaptive thermogenesis: International Journal of Obesity Vol 31(2) Feb 2007, 204-212.
- Marks, L. E. (1983). "Minor" Senses of "Major" Importance: PsycCRITIQUES Vol 28 (10), Oct, 1983.
- McKemy, D. D., Neuhausser, W. M., & Julius, D. (2002). Identification of a cold receptor reveals a general role for TRP channels in thermosensation: Nature Vol 416(6876) Mar 2002, 52-58.
- Meyer, R. A., & Campbell, J. N. (1981). Evidence for two distinct classes of unmyelinated nociceptive afferents in monkey: Brain Research Vol 224(1) Nov 1981, 149-152.
- Mitchell, D., & Hellon, R. F. (1974). Latencies in a thermosensitive pathway: Experientia Vol 30(10) 1974, 1159-1161.
- Montell, C. (2003). Thermosensation: Hot findings make TRPNs very cool: Current Biology Vol 13(12) Jun 2003, R476-R478.
- Nagy, J. I., Emson, P. C., & Iversen, L. L. (1981). A re-evaluation of the neurochemical and antinociceptive effects of intrathecal capsaicin in the rat: Brain Research Vol 211(2) May 1981, 497-502.
- Norwich, K. H. (2001). Determination of saltiness from the laws of thermodynamics: Estimating the gas constant from psychophysical experiments: Chemical Senses Vol 26(8) Oct 2001, 1015-1022.
- Novak, J. C., Lovell, J. A., Stuesse, S. L., Cruce, W. L. R., McBurney, D. L., & Crisp, T. (1999). Aging and neuropathic pain: Brain Research Vol 833(2) Jul 1999, 308-310.
- Ohara, S., & Lenz, F. A. (2003). Medial Lateral Extent of Thermal and Pain Sensations Evoked By Microstimulation in Somatic Sensory Nuclei of Human Thalamus: Journal of Neurophysiology Vol 90(4) Oct 2003, 2367-2377.
- Okazawa, M., Takao, K., Hori, A., Shiraki, T., Matsumura, K., & Kobayashi, S. (2002). Ionic basis of cold receptors acting as thermostats: Journal of Neuroscience Vol 22(10) May 2002, 3994-4001.
- Pasto, J. D. (1982). Thermal responses and thermoreceptor location in Procambarus acutus acutus (Girard): Dissertation Abstracts International.
- Patapoutian, A., Peier, A. M., Story, G. M., & Viswanath, V. (2003). ThermoTRP channels and beyond: Mechanisms of temperature sensation: Nature Reviews Neuroscience Vol 4(7) Jul 2003, 529-539.
- Roberts, W. W., & Martin, J. R. (1974). Peripheral thermoreceptor control of thermoregulatory responses of the rat: Journal of Comparative and Physiological Psychology Vol 87(6) Dec 1974, 1109-1118.
- Robinson, C. J., Torebjork, H. E., & LaMotte, R. H. (1983). Psychophysical detection and pain ratings of incremental thermal stimuli: A comparison with nociceptor responses in humans: Brain Research Vol 274(1) Sep 1983, 87-106.
- Saumet, J.-L., Chery-Croze, S., & Duclaux, R. (1985). Response of cat skin mechanothermal nociceptors to cold stimulation: Brain Research Bulletin Vol 15(5) Nov 1985, 529-532.
- Sumino, R., & Dubner, R. (1981). Response characteristics of specific thermoreceptive afferents innervating monkey facial skin and their relationship to human thermal sensitivity: Brain Research Reviews Vol 3(2) Oct 1981, 105-122.
- Towell, A. D., Purves, A. M., & Boyd, S. G. (1996). CO-sub(2) laser activation of nociceptive and non-nociceptive thermal afferents from hairy and glabrous skin: Pain Vol 66(1) Jul 1996, 79-86.
- Tsirul'nikov, E. M., Nemenov, M. I., & Andreeva, I. G. (1997). Laser irradiation in studies of skin sensitivity: Sensory Systems Vol 11(2) Apr-Jun 1997, 163-171.
- Yaitchnikov, I. K. (1972). The bioelectrical activity of the rabbit brain in response to local changes of temperature in the thermoreceptor area of the thermoregulatory center: Fiziologicheskii Zhurnal SSSR im I M Sechenova Vol 58(3) Mar 1972, 350-356.
- Zars, T. (2003). Hot and cold in Drosophila larvae: Trends in Neurosciences Vol 26(11) Nov 2003, 575-577.
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