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At least 19 recordsLinked to original sources
PubMed1979

[Vagal thermoreceptors in the gastro-intestinal area. Their role in the regulation of the digestive motility (author's transl)].

In anaesthetized cats, sensory vagal units were recorded in the nodose ganglion by means of extracellular glass microelectrodes. In the antrum and the duodenum we have found receptors tonically activated by warm (38-51 degrees C with an optimum at 46-49 degrees C) or cold (36-10 degrees C with an optimum at 12-10 degrees C) solutions. These receptors did not respond to mechanical stimuli (compression and distension of the viscera) and to chemical ones (perfusion with glucose and acid solutions). Thus they did not belong to polymodal type, but they must be considered as true thermoreceptors, specifically sensitive to warm or cold stimulations. The gastro-duodenal thermoreceptors were connected to non-medullated vagal fibres (conduction velocity: 0.8-1.4 m/s). On the other hand, the role of the gastro-duodenal vagal thermoreceptors in the regulation of the digestive motility was studied. By using several electromyographic recordings, it was possible to show that the cold and warm stimulations of the duodenum which elicited thermoreceptor responses, induced an inhibition of the electrical activity of the antrum. The changes persisted after bisplanchnectomy, but disappeared completely after bivagotomy. From these facts it was concluded that the vagal thermoreceptors were involved in the nervous regulations of the gastro-duodenal motility.

Animals↗
PubMed1990

[The frequency and sequence of the biopotentials of the cold thermoreceptors at different skin temperatures].

Electrical activity of the skin cold thermoreceptors was studied in the rabbit nasolabial area at a gradually decreasing temperature of the skin from 39.0 to 7.7 degrees C. The range of firing rate, the temperature of the maximal discharge, and the character of the discharge sequence at different skin temperature, were recorded for every thermoreceptor. The majority of the thermoreceptors were characterized by bursts of discharges (2-10 and more) at a certain skin temperature. The analysis of the data obtained revealed a wide variety of responses of the cold thermoreceptors to continuous drop of the skin temperature.

Animals↗
PubMed1985

[Characteristics of the reactions of thermoreceptors located in different layers of the skin].

Discharges of different skin cold--thermoreceptors in response to abrupt changes of the thermode temperature (20 degrees C to 42 degrees C and vice versa) divided the thermoreceptors into 5 groups: I and II groups of thermoreceptors with typical short--latency responses; III, IV and V groups with delayed responses; the latency increasing from I to V group with reverse pattern of intensity. The differences in responses seem to depend on different depth of thermoreceptors location in the skin.

Animals↗
PubMed1980

[Effect of the temperature of different skin layers on the spike activity of cold thermoreceptors].

Changing of skin surface temperature by 18 degrees (from 22 degrees to 40 degrees) induced about 4.5 degrees temperature oscillations at 2--3 mm depth with 5--7 min delay. Simultaneous recording of activity of the rabbit upper lip cold thermoreceptors revealed that in 9 thermoreceptors alteration of activity occurred synchronously with skin surface temperature changes. In 7 thermoreceptors changes of activity were related to deep skin layer temperature. Localization of thermoreceptors in different skin layers seems to enable the organism to assess direction and intensity of the warmth flow spreading through the skin.

Action Potentials↗
PubMed1994

COMPARISON BETWEEN THERMORECEPTOR AND MECHANORECEPTOR CURRENTS IN PARAMECIUM CAUDATUM

1. A voltage-clamped Paramecium produced an inward membrane current upon thermal or mechanical stimulation of its anterior region, whereas it produced an outward membrane current upon similar stimulation of its posterior region. 2. Anterior thermo- and mechanoreceptor currents decreased when the membrane potential was shifted in a positive direction, showing sign reversal at a positive membrane potential, whereas posterior thermo- and mechanoreceptor currents decreased when the membrane potential was shifted in a negative direction, showing sign reversal at a membrane potential more negative than the resting potential. 3. The reversal potential for both anterior receptor currents shifted in a positive direction when external [Ca2+] was increased, whereas those for both posterior receptor currents shifted in a positive direction when external [K+] was increased. 4. External [Mg2+], [Mn2+], [Na+], [Rb+] and [TEA+] had similar effects on the thermo- and mechanoreceptor currents. 5. Thermoreceptor currents decreased whereas mechanoreceptor currents increased as the ambient temperature was raised. 6. When a mechanical stimulus was applied to the membrane where a thermoreceptor current was being produced, an algebraic summation of these receptor currents occurred. 7. It is concluded that thermoreceptor currents are dependent on ion channels different from those responsible for the mechanoreceptor currents, although the ionic pores for the channels are similar to each other in various respects. 8. A possibility that a thermoreceptor mechanism exclusively shares a Ca2+ pore in the anterior membrane, or a K+ pore in the posterior membrane, with a mechanoreceptor mechanism is discussed.

Journal Article↗
PubMed2007

Central and peripheral thermoreceptors. Comparative analysis of the effects of prolonged adaptation to cold and noradrenaline.

This report presents results obtained from many years of study of the effects of prolonged adaptation to cold and noradrenaline on the spike activity of central hypothalamic and peripheral skin thermoreceptors. The involvement of the sympathetic nervous system in forming adaptive changes in the regulatory characteristics of temperature homeostasis and the significance of the various components of thermoreceptor activity to the formation of effector responses are discussed. The roles of different groups of thermoreceptors in forming temperature sensations are analyzed.

Action Potentials↗
PubMed2005

[Central and peripheral thermoreceptors. Comparative analysis of effects of the long-term adaptation to cold and noradrenaline].

The data obtained in our experiments concerning the effect of long-tern adaptation to cold and noradrenaline on impulse activity of the central hypothalamic and peripheral skin thermoreceptors, are reviewed. The problems of sympathetic system participator in cold adaptive modifications and importance of thermoreceptors in formation of cold-defense responses, as well as the role of different types of thermoreceptors in thermal sensation, are discussed.

Adaptation, Physiological↗
PubMed1980

[Relation between the temperature of different skin layers and changes in the firing of cold cutaneous thermoreceptors].

On sharp changes (from 20 to 42 degrees C and vice versa) of temperature of the thermode placed on the upper lip of anesthetized rabbit, the temperature under the epidermis at the depth of 0.1--0.2 mm changed at the rate of 2 degrees/sec by 17.6 degrees .C on the average. At the depth of 2--3 mm the temperature only changed by 4.5 degrees C at the rate of 0.015 degrees/sec. Simultaneous recording of single cold thermoreceptors revealed two types of responses to alteration of the thermode temperature: with rapid increase in the firing rate during cooling and sharp decrease during warming up (18 thermoreceptors); and with slow, gradual change of the firing rate (10 receptors). The data obtained suggest that the cold thermoreceptors are situated in different skin layers. This enables the organism to register the skin temperature gradient as well as the transdermal warmth flows.

Action Potentials↗
PubMed1993

[The effect of cooling using ice on the impulse activity of the skin cold thermoreceptors in the rabbit].

The temperature of the rabbit skin was reduced from 32.8 +/- 0.5 degrees C to 4.8 +/- 0.6 degrees C. The majority of the thermoreceptors responded to the cooling with an initial increase of the firing rate up to the maximum and its subsequent decrease up to its complete cessation. The lower temperature limits varied from 15 to 4 degrees C in different skin cold thermoreceptors. Some thermoreceptors retained high firing rate even at the temperature 6-8 degrees C. After removing the ice and warming up of the skin, the firing rate increased again up to the maximum and decreased subsequently to the minimum. Thermosensitive structures seem to exist in the skin transmitting the information on low values of the skin temperature to the centres of thermoregulation.

Animals↗
PubMed1992

[The modulation of the functional properties of the skin thermoreceptors].

The characteristic property of skin cold receptors is the presence of static and dynamic activity with their maximum at any skin temperature. Parallel with the common properties there are some differences in the temperature range of receptors' functioning, frequency of static and dynamic activity, concentration of sensitive receptors on the skin. Mechanisms of these differences are unknown. It is found that the character of skin cold receptors functioning can be changed in individual life of the organism. Some parameters of static and dynamic activity as well as concentration of cold receptors functioning change both with adaptation of the organism to cold and with a rise of the noradrenaline concentration in blood. The reason of adaptive modifications of skin thermoreceptors may be an increase of their sensitivity to noradrenaline observed with adaptation to cold. It can be supposed that the modulating influence of biological active substances is very important in forming activity and sensitivity of skin thermoreceptors.

Adaptation, Physiological↗
PubMed2000

Phase-space structure of a thermoreceptor.

We analyze the phase-space structure of a model for thermoreceptors in fish and mammals. As a function of the temperature we identify a period doubling scenario at low temperatures, a regime where an unstable stationary fixed point collides with the attractor and blocks the thermoreceptor, and a transition from period n+1 to period n as the temperature is further increased. The period reduction phenomenon is due to an autoresonance between fast and slow ion channels and shows the features typical for mode locking.

Action Potentials↗
PubMed1989

The distribution of thermoreceptors within the nasal cavity.

The distribution of thermoreceptors within the nasal vestibule (that part of the nasal cavities lined with skin) and nasal cavum (that part of the nasal cavities lined with respiratory epithelium) was studied in 20 subjects. The distribution was compared with that of the malar skin adjacent to the nose. No thermoreceptors were located in the nasal cavum but the nasal vestibule contained a dense distribution of cold receptors (3.5 receptors per cm2) and warm receptors (3.2 receptors per cm2). The corresponding density of receptors in the malar skin was 2.7 receptors per cm2 and 2.6 receptors per cm2. The difference in distribution density between the nasal vestibule and the malar skin was significant (P less than 0.05). The implications of these findings are discussed.

Adult↗
PubMed1997

Perception and gut reflexes induced by stimulation of gastrointestinal thermoreceptors in humans.

1. Experimental studies in animals suggest the existence of thermoreceptors in the gastrointestinal tract. Our aim was to investigate the distribution and specificity of upper gut thermoreceptors in humans. 2. In healthy subjects, thermal stimulation of the stomach (n = 8) and the small intestine (n = 6) was produced by means of a thermostat, which recirculates water at adjusted temperatures through an ultrathin intraluminal bag. Progressively warm (42, 47 and 52 degrees C) and cold (32, 22 and 12 degrees C) stimuli of 3 min duration were alternately applied at 13 min intervals. Perception was scored on a scale of 0-6 and gastric tone responses were measured with a barostat. 3. Thermal stimuli induced specific responses: cold stimuli induced abdominal cold sensation and a reflex contraction of the stomach, whereas warm stimuli induced warm sensation and a reflex gastric relaxation. 4. Thermal stimuli induced similar stimulus-related perception in the stomach and small intestine (temperatures between 12 and 49.5 +/- 0.5 degrees C were tolerated). 5. The reflex responses were site specific. Warm and cold stimulation of the stomach induced gastric reflexes (76 +/- 26 ml isobaric expansion at 47 degrees C, and 68 +/- 10 ml contraction at 12 degrees C; P < 0.05 for both). However, only warm, not cold, stimulation of the intestine induced enterogastric reflexes. 6. These results indicate that in humans, warm and cold receptors are distributed along the gastrointestinal tract and project afferent input both into perception and reflex circuits with specific topographic organization.

Adult↗
PubMed1983

[Localization of cold thermoreceptors in various layers of the skin].

Impulses from cold thermoreceptors were recorded during changes of the temperature in superficial and deep skin layers of the rabbit upper lip. The temperature of stimulating thermodes was sharply changed from 20 degrees C to 40 degrees C and back again in each of the thermodes. 7 out of 10 receptors revealed sharp alterations in the impulse flow following changes of the temperature in the surface thermode, whereas changes of temperature in the deep thermode (2-3 mm under the skin) induced slow alterations in the activity of the same receptor. 3 receptors responded only to changes in the deep thermode. The data suggest that thermoreceptors can be found in different skin layers and register the skin temperature gradient or the heat flows across the skin. This enables to propose a new regard on the mechanism of temperature homeostasis maintenance.

Animals↗
PubMed1978

[Role of vascular thermoreceptors in the mechanism of cold tremor inhibition by oxotremorine, seduxen and phentolamine].

Intravenous infusion of oxotremorine, seduxene, and phentolamine to cats not only decreased the cold-induced tremor, but also reduced the subcutaneous vein receptor impulses. Diminished activity of the vascular thermoreceptors served as an additional component in the mechanisms of the inhibitory effect of oxotremorine and seduxene on cold tremor. Reduction of the thermoreceptors activity after phentolamine administration is primary, and may be considered as the leading factor in the cold tremor inhibition.

Animals↗
PubMed1982

Electrophysiologic properties and role of the vagal thermoreceptors of lower esophagus and stomach of cat.

Vagal unitary discharges were elicited in anesthetized cats by thermal stimulation of the lower thoracic esophagus and stomach. Discharges were recorded from the nodose ganglion, using extracellular glass microelectrodes. Three types of receptors were distinguished according to the temperature ranges at which they discharged: the cold receptors (10 degrees-36 degrees C), the warm receptors (39 degrees-50 degrees C), and the mixed receptors (10 degrees-35 degrees C and 40 degrees-50 degrees C). All endings were connected to unmyelinated fibers (conduction velocities around 1 m/s). These receptors are stimulated neither by mechanical (strong distention, localized stroking of mucosa) nor by chemical (acid and glucose solutions) stimuli. Therefore they must be considered as true thermoreceptors. Stimulation of the esophageal and gastric thermoreceptors produced changes both in esophageal motility and in respiratory frequency. It was concluded that they are involved in coordination of digestive activity as well as in thermoregulation.

Animals↗
PubMed1998

[Modulating effect of peripheral thermoreceptors on human respiration].

Peripheral thermoreceptors substantially modulate respiratory parameters under normal and cooling conditions. Functional changes in peripheral thermoreceptors after cold adaptation promote alterations of the external respiratory system. Artificial modulation of the number of sensitive cold receptors by norepinephrine is shown by the pattern of a respiratory response to cooling. The pattern of respiration may be differently changed by affecting cold receptors of different sites. Thus, the possibility of initiating the same effector response does not mean that these sensors are equal in their responses. With a small number of effector organs in the body, the field of application of each effector is expanded due to the fact that they may be exposed to a variety of reception that differently modulating the function of an effector organ.

Adaptation, Physiological↗
PubMed1969

Cutaneous thermoreceptors in primates and sub-primates.

1. Cutaneous thermoreceptors were examined electrophysiologically in primates (monkey, baboon) and in sub-primates (dog and rat) by recording from single units dissected from peripheral nerves.2. Thermal stimuli were delivered from thermodes in contact with the skin.3. Primate ;cold' receptors had spot-like receptive fields and were found in both hairy and glabrous skin. The conduction velocities of the axons ranged from 0.6 to 15.3 m/sec.4. The discharge from the primate receptors characteristically appeared in bursts with intervals of silence within the range temperatures of 18-40 degrees C. Static and dynamic sensitivity curves were established, with maxima about 30 degrees C.5. Cold receptors in the lip of the dog had maximal sensitivity at 31-37 degrees C. The axons were myelinated with conduction velocities less than 20 m/sec.6. ;Warm' receptors, with maximal sensitivity at 40 degrees C and non-myelinated axons, were abundant in the scrotal nerve of the rat. The ;cold' receptors had maximal responses at 23-28 degrees C.7. The ;spurious' thermoreceptor behaviour of slowly adapting mechanoreceptors is described and the way in which they may distort integrated potential records from whole nerves is analysed.

Animals↗