The Experts below are selected from a list of 399 Experts worldwide ranked by ideXlab platform

Yasuyuki Kitada - One of the best experts on this subject based on the ideXlab platform.

  • Parasympathetic Postganglionic Nerve Fibers in the Fungiform Papillae of the Frog
    Olfaction and Taste XI, 1994
    Co-Authors: Katsuhiro Inoue, Yasuyuki Kitada
    Abstract:

    The Nerve bundle in each fungiform papilla of the frog consists of afferent, and sympathetic and parasympathetic efferent Nerve Fibers. Efferent control of the gustatory system has been postulated from electronphysiological evidence, but there is inadequate morphological evidence for such a conclusion. Some unmyelinated Nerve Fibers in the Nerve bundle of each fungiform papilla originate from parasympathetic Postganglionic neurons within the lingual branch of the glossopharyngeal Nerve [1,2]. Particular Nerve endings, designated parasympathetic efferent according to morphological criteria, namely, the presence of accumulations of clear synaptic vesicles and mitochondria, besides a specific membrane system, at the regions of contact between the Nerve endings and taste cells, have been observed in the taste organs of mammals, fish, and frogs. However, the presence of sensory Nerve endings that contained many typical, clear synaptic vesicles of the type usually associated with cholinergic Fibers has also been reported.

  • parasympathetic Postganglionic Nerve Fibers in the fungiform papillae of the bullfrog rana catesbeiana
    Brain Research, 1992
    Co-Authors: Katsuhiro Inoue, T Yamaai, Yasuyuki Kitada
    Abstract:

    An investigation was made of the precise origin of the unmyelinated Nerve Fibers in the fungiform papillae of the bullfrog's tongue. Some unmyelinated Nerve Fibers in the fungiform papillae originate from the parasympathetic Postganglionic cells in the glossopharyngeal Nerve. Axonal enlargements of the parasympathetic Nerve Fibers were in close contact with the Merkel-like basal or supporting cells in the taste disk. These results seem to provide morphological evidence for the existence of an efferent control system in the taste disk.

Hong Wei - One of the best experts on this subject based on the ideXlab platform.

  • the influence of chemical sympathectomy on pain responsivity and α2 adrenergic antinociception in neuropathic animals
    Neuroscience, 2002
    Co-Authors: Hong Wei, E Jyvasjarvi, Sirkku Niissalo, Mika Hukkane, E Waris, Y T Konttine, Antti Pertovaara
    Abstract:

    Abstract We studied the effect of chemical sympathectomy by 6-hydroxydopamine (6-OHDA) on pain behavior and α 2 -adrenergic antinociception in rats with a spinal Nerve ligation-induced neuropathy. For assessment of α 2 -adrenergic antinociception, the rats were treated systemically with two α 2 -adrenoceptor agonists, one of which only poorly (MPV-2426) and the other very well (dexmedetomidine) penetrates the blood–brain barrier. Moreover, the effect of MPV-2426 on spontaneous activity of dorsal root Nerve Fibers proximal to the Nerve injury was determined. Systemic treatment with 6-OHDA produced a marked decrease in immunocytochemical labeling of sympathetic Nerve Fibers in the skin but it produced no marked change in basal pain sensitivity to mechanical stimulation either in neuropathic or sham-operated animals. Systemic administration of MPV-2426 and dexmedetomidine produced a dose-dependent tactile antiallodynic effect in neuropathic animals. Intraplantar injection of MPV-2426 had an identical antiallodynic effect independent of whether it was injected into the neuropathic or contralateral hindpaw. In a test of mechanical nociception and hyperalgesia, dexmedetomidine markedly attenuated pain responses in all experimental groups, whereas MPV-2426 had a weak but significant pain attenuating effect only in neuropathic animals. In the tail flick test, both α 2 -adrenoceptor agonists had a significant antinociceptive effect. The pain attenuating effect of MPV-2426 was enhanced by pretreatment with 6-OHDA, except in a test of tactile allodynia. MPV-2426-induced modulation of spontaneous activity was not a general property of dorsal root Fibers proximal to the injury. The results indicate that a chemical destruction of sympathetic Postganglionic Nerve Fibers innervating the skin does not markedly influence cutaneous pain sensitivity nor is it critical for the α 2 -adrenoceptor agonist-induced attenuation of pain behavior in neuropathic or non-neuropathic animals. Chemical sympathectomy, independent of neuropathy, enhanced the pain attenuating effect by MPV-2426, probably due to a peripheral action, whereas in non-sympathectomized control and neuropathic animals peripheral mechanisms have only a minor, if any, role in the α 2 -adrenoceptor agonist-induced antinociception.

  • peripheral effects of morphine in neuropathic rats role of sympathetic Postganglionic Nerve Fibers
    European Journal of Pharmacology, 2001
    Co-Authors: Antti Pertovaara, Hong Wei
    Abstract:

    We studied the contribution of peripheral opioid receptors to the morphine-induced antinociception in rats with a spinal Nerve ligation-induced neuropathy. Intraplantar (i.pl.) injection of morphine produced a stronger suppression of nociceptive reflex responses of the neuropathic limb following ipsilateral, than contralateral, administration, whereas the morphine-induced effect on the control limb was independent of the injection side. Antinociception induced by systemically administered morphine was significantly attenuated by i.pl. injection of a peripherally acting opioid receptor antagonist in neuropathic but not in sham-operated rats. Following chemical sympathectomy with 6-hydroxydopamine, antinociception was achieved at a lower dose ipsilaterally, than contralaterally, following i.pl. administration of morphine, and the morphine-induced antinociception was attenuated by a peripherally acting opioid receptor antagonist. These results indicate that peripheral opioid receptors may contribute to the morphine-induced antinociception in the spinal Nerve ligation-induced model of neuropathy. Sympathectomy of the neuropathic limb may underlie, at least partly, the increased peripheral efficacy of morphine in neuropathy.

Katsuhiro Inoue - One of the best experts on this subject based on the ideXlab platform.

  • Parasympathetic Postganglionic Nerve Fibers in the Fungiform Papillae of the Frog
    Olfaction and Taste XI, 1994
    Co-Authors: Katsuhiro Inoue, Yasuyuki Kitada
    Abstract:

    The Nerve bundle in each fungiform papilla of the frog consists of afferent, and sympathetic and parasympathetic efferent Nerve Fibers. Efferent control of the gustatory system has been postulated from electronphysiological evidence, but there is inadequate morphological evidence for such a conclusion. Some unmyelinated Nerve Fibers in the Nerve bundle of each fungiform papilla originate from parasympathetic Postganglionic neurons within the lingual branch of the glossopharyngeal Nerve [1,2]. Particular Nerve endings, designated parasympathetic efferent according to morphological criteria, namely, the presence of accumulations of clear synaptic vesicles and mitochondria, besides a specific membrane system, at the regions of contact between the Nerve endings and taste cells, have been observed in the taste organs of mammals, fish, and frogs. However, the presence of sensory Nerve endings that contained many typical, clear synaptic vesicles of the type usually associated with cholinergic Fibers has also been reported.

  • parasympathetic Postganglionic Nerve Fibers in the fungiform papillae of the bullfrog rana catesbeiana
    Brain Research, 1992
    Co-Authors: Katsuhiro Inoue, T Yamaai, Yasuyuki Kitada
    Abstract:

    An investigation was made of the precise origin of the unmyelinated Nerve Fibers in the fungiform papillae of the bullfrog's tongue. Some unmyelinated Nerve Fibers in the fungiform papillae originate from the parasympathetic Postganglionic cells in the glossopharyngeal Nerve. Axonal enlargements of the parasympathetic Nerve Fibers were in close contact with the Merkel-like basal or supporting cells in the taste disk. These results seem to provide morphological evidence for the existence of an efferent control system in the taste disk.

Antti Pertovaara - One of the best experts on this subject based on the ideXlab platform.

  • the influence of chemical sympathectomy on pain responsivity and α2 adrenergic antinociception in neuropathic animals
    Neuroscience, 2002
    Co-Authors: Hong Wei, E Jyvasjarvi, Sirkku Niissalo, Mika Hukkane, E Waris, Y T Konttine, Antti Pertovaara
    Abstract:

    Abstract We studied the effect of chemical sympathectomy by 6-hydroxydopamine (6-OHDA) on pain behavior and α 2 -adrenergic antinociception in rats with a spinal Nerve ligation-induced neuropathy. For assessment of α 2 -adrenergic antinociception, the rats were treated systemically with two α 2 -adrenoceptor agonists, one of which only poorly (MPV-2426) and the other very well (dexmedetomidine) penetrates the blood–brain barrier. Moreover, the effect of MPV-2426 on spontaneous activity of dorsal root Nerve Fibers proximal to the Nerve injury was determined. Systemic treatment with 6-OHDA produced a marked decrease in immunocytochemical labeling of sympathetic Nerve Fibers in the skin but it produced no marked change in basal pain sensitivity to mechanical stimulation either in neuropathic or sham-operated animals. Systemic administration of MPV-2426 and dexmedetomidine produced a dose-dependent tactile antiallodynic effect in neuropathic animals. Intraplantar injection of MPV-2426 had an identical antiallodynic effect independent of whether it was injected into the neuropathic or contralateral hindpaw. In a test of mechanical nociception and hyperalgesia, dexmedetomidine markedly attenuated pain responses in all experimental groups, whereas MPV-2426 had a weak but significant pain attenuating effect only in neuropathic animals. In the tail flick test, both α 2 -adrenoceptor agonists had a significant antinociceptive effect. The pain attenuating effect of MPV-2426 was enhanced by pretreatment with 6-OHDA, except in a test of tactile allodynia. MPV-2426-induced modulation of spontaneous activity was not a general property of dorsal root Fibers proximal to the injury. The results indicate that a chemical destruction of sympathetic Postganglionic Nerve Fibers innervating the skin does not markedly influence cutaneous pain sensitivity nor is it critical for the α 2 -adrenoceptor agonist-induced attenuation of pain behavior in neuropathic or non-neuropathic animals. Chemical sympathectomy, independent of neuropathy, enhanced the pain attenuating effect by MPV-2426, probably due to a peripheral action, whereas in non-sympathectomized control and neuropathic animals peripheral mechanisms have only a minor, if any, role in the α 2 -adrenoceptor agonist-induced antinociception.

  • peripheral effects of morphine in neuropathic rats role of sympathetic Postganglionic Nerve Fibers
    European Journal of Pharmacology, 2001
    Co-Authors: Antti Pertovaara, Hong Wei
    Abstract:

    We studied the contribution of peripheral opioid receptors to the morphine-induced antinociception in rats with a spinal Nerve ligation-induced neuropathy. Intraplantar (i.pl.) injection of morphine produced a stronger suppression of nociceptive reflex responses of the neuropathic limb following ipsilateral, than contralateral, administration, whereas the morphine-induced effect on the control limb was independent of the injection side. Antinociception induced by systemically administered morphine was significantly attenuated by i.pl. injection of a peripherally acting opioid receptor antagonist in neuropathic but not in sham-operated rats. Following chemical sympathectomy with 6-hydroxydopamine, antinociception was achieved at a lower dose ipsilaterally, than contralaterally, following i.pl. administration of morphine, and the morphine-induced antinociception was attenuated by a peripherally acting opioid receptor antagonist. These results indicate that peripheral opioid receptors may contribute to the morphine-induced antinociception in the spinal Nerve ligation-induced model of neuropathy. Sympathectomy of the neuropathic limb may underlie, at least partly, the increased peripheral efficacy of morphine in neuropathy.

T Yamaai - One of the best experts on this subject based on the ideXlab platform.

  • parasympathetic Postganglionic Nerve Fibers in the fungiform papillae of the bullfrog rana catesbeiana
    Brain Research, 1992
    Co-Authors: Katsuhiro Inoue, T Yamaai, Yasuyuki Kitada
    Abstract:

    An investigation was made of the precise origin of the unmyelinated Nerve Fibers in the fungiform papillae of the bullfrog's tongue. Some unmyelinated Nerve Fibers in the fungiform papillae originate from the parasympathetic Postganglionic cells in the glossopharyngeal Nerve. Axonal enlargements of the parasympathetic Nerve Fibers were in close contact with the Merkel-like basal or supporting cells in the taste disk. These results seem to provide morphological evidence for the existence of an efferent control system in the taste disk.