The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
Jens Schouenborg - One of the best experts on this subject based on the ideXlab platform.
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On the Cutaneous Receptors contributing to withdrawal reflex pathways in the decerebrate spinal rat.
Experimental brain research, 1998Co-Authors: Han-rong Weng, Jens SchouenborgAbstract:Previous studies indicate that the withdrawal reflex system in the rat has a “modular” organization, each reflex pathway performing a specific sensorimotor transformation. Here, we wished to clarify which Cutaneous Receptors contribute to this system and to determine whether there are differences in this respect between reflex pathways of different muscles. Withdrawal reflexes of the peroneus longus, extensor digitorum longus, and semitendinosus muscles were recorded with EMG techniques during high reflex excitability in decerebrate spinal rats (n=26). While maintained innocuous pressure on glabrous skin could elicit a sustained reflex activity in all muscles studied, vibration of glabrous skin (10–300 Hz) always failed to evoke a reflex response, suggesting that slowly adapting, but not rapidly adapting, low-threshold mechanoreceptive fibers from this type of skin contribute to withdrawal reflex pathways. Thermal stimulation in the innocuous range, i.e., cooling from 32 to 17°C, or warming the skin from 32 to 41°C, always failed to produce reflex responses, indicating that neither cold nor warm Receptors contribute to withdrawal reflex pathways. When either cooling or warming the skin to the noxious temperatures of 1°C or above 45°C, respectively, a reflex discharge was often evoked in the muscles studied. Intradermal administration of histamine, a potent pruritogenic substance, produced very weak, or no, reflex response. In contrast, mustard oil produced vigorous reflex responses in all muscles studied. These findings suggest that some chemonociceptors contribute only weakly, or not at all, to withdrawal reflex pathways. The present data suggest that a selective set of Cutaneous Receptors contribute to withdrawal reflex pathways and that different withdrawal reflex pathways receive input from essentially the same Cutaneous Receptor types.
Han-rong Weng - One of the best experts on this subject based on the ideXlab platform.
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On the Cutaneous Receptors contributing to withdrawal reflex pathways in the decerebrate spinal rat.
Experimental brain research, 1998Co-Authors: Han-rong Weng, Jens SchouenborgAbstract:Previous studies indicate that the withdrawal reflex system in the rat has a “modular” organization, each reflex pathway performing a specific sensorimotor transformation. Here, we wished to clarify which Cutaneous Receptors contribute to this system and to determine whether there are differences in this respect between reflex pathways of different muscles. Withdrawal reflexes of the peroneus longus, extensor digitorum longus, and semitendinosus muscles were recorded with EMG techniques during high reflex excitability in decerebrate spinal rats (n=26). While maintained innocuous pressure on glabrous skin could elicit a sustained reflex activity in all muscles studied, vibration of glabrous skin (10–300 Hz) always failed to evoke a reflex response, suggesting that slowly adapting, but not rapidly adapting, low-threshold mechanoreceptive fibers from this type of skin contribute to withdrawal reflex pathways. Thermal stimulation in the innocuous range, i.e., cooling from 32 to 17°C, or warming the skin from 32 to 41°C, always failed to produce reflex responses, indicating that neither cold nor warm Receptors contribute to withdrawal reflex pathways. When either cooling or warming the skin to the noxious temperatures of 1°C or above 45°C, respectively, a reflex discharge was often evoked in the muscles studied. Intradermal administration of histamine, a potent pruritogenic substance, produced very weak, or no, reflex response. In contrast, mustard oil produced vigorous reflex responses in all muscles studied. These findings suggest that some chemonociceptors contribute only weakly, or not at all, to withdrawal reflex pathways. The present data suggest that a selective set of Cutaneous Receptors contribute to withdrawal reflex pathways and that different withdrawal reflex pathways receive input from essentially the same Cutaneous Receptor types.
S.j.w. Lisney - One of the best experts on this subject based on the ideXlab platform.
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The relationship between unmyelinated afferent type and neurogenic plasma extravasation in normal and reinnervated rat skin.
Neuroscience, 1992Co-Authors: L.a.m. Bharali, S.j.w. LisneyAbstract:Abstract Electrophysiological experiments have been carried out on rats to examine the relationship between plasma extravasation into skin and antidromic activation of individual unmyelinated afferent fibres supplying Cutaneous Receptors, particularly polymodal nociceptors. Normal animals and ones in which the skin had been reinnervated after peripheral nerve transection 26–52 weeks before were studied. In the normal animals 12 of 18 (66%) polymodal nociceptor afferents showed evidence of plasma extravasation after antidromic stimulation of the nerve filament from which they were initially recorded. Antidromic stimulation of other types of unmyelinated unit gave no detectable signs of plasma extravasation. The results from the animals with regenerated nerves were similar with 15 of 21 (71%) of the polymodal nociceptor afferents showing clear signs of plasma extravasation after antidromic activation and the other types of unit giving no signs of such a response. These results show that while antidromic stimulation of a Cutaneous nerve after intravascular administration of Evans Blue dye can be used to get a general view of the extent of innervation by polymodal nociceptors, it does not necessarily show the entire distribution of these Receptors. It is likely that the ability or lack of ability of a polymodal nociceptor afferent to enhance vascular permeability, and so bring about plasma extravasation, is related to its neuropeptide content, and thus it follows that this might be a useful criterion for separating this broad class of Cutaneous Receptor into sub-groups.
L.a.m. Bharali - One of the best experts on this subject based on the ideXlab platform.
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The relationship between unmyelinated afferent type and neurogenic plasma extravasation in normal and reinnervated rat skin.
Neuroscience, 1992Co-Authors: L.a.m. Bharali, S.j.w. LisneyAbstract:Abstract Electrophysiological experiments have been carried out on rats to examine the relationship between plasma extravasation into skin and antidromic activation of individual unmyelinated afferent fibres supplying Cutaneous Receptors, particularly polymodal nociceptors. Normal animals and ones in which the skin had been reinnervated after peripheral nerve transection 26–52 weeks before were studied. In the normal animals 12 of 18 (66%) polymodal nociceptor afferents showed evidence of plasma extravasation after antidromic stimulation of the nerve filament from which they were initially recorded. Antidromic stimulation of other types of unmyelinated unit gave no detectable signs of plasma extravasation. The results from the animals with regenerated nerves were similar with 15 of 21 (71%) of the polymodal nociceptor afferents showing clear signs of plasma extravasation after antidromic activation and the other types of unit giving no signs of such a response. These results show that while antidromic stimulation of a Cutaneous nerve after intravascular administration of Evans Blue dye can be used to get a general view of the extent of innervation by polymodal nociceptors, it does not necessarily show the entire distribution of these Receptors. It is likely that the ability or lack of ability of a polymodal nociceptor afferent to enhance vascular permeability, and so bring about plasma extravasation, is related to its neuropeptide content, and thus it follows that this might be a useful criterion for separating this broad class of Cutaneous Receptor into sub-groups.
Victor Candas - One of the best experts on this subject based on the ideXlab platform.
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Ageing and thermal responses during passive heat exposure: sweating and sensory aspects
European Journal of Applied Physiology, 2007Co-Authors: Andre Dufour, Victor CandasAbstract:The present study investigated the causes of decreases in sweating capacities with age. The hypothesis was that the decrease in local sweat rate in older individuals was associated with deterioration in thermal Cutaneous Receptor responses leading to weaker signals to the thermoregulatory center (i.e. the hypothalamus). Fifteen older (>60 years), 15 middle-aged (40–50 years) and 15 young (20–30 years) men were exposed for 90 min to a 40°C, 14°C dew point environment. The thermal detection threshold was measured at 9 different Cutaneous locations. The results showed a reduced sweat output with age, and that older and middle-aged subjects had higher core and skin temperatures than young subjects. In addition, there was a sensory thermal sensitivity decrease and a correlation between thermal sensitivity and local sweat rate in older and middle-aged subjects, but not in young subjects. The data suggest that the age-related effects on thermoregulatory mechanisms reflect local skin changes rather than central alterations.
