The Experts below are selected from a list of 4545 Experts worldwide ranked by ideXlab platform

Radhouane Dallel - One of the best experts on this subject based on the ideXlab platform.

  • different processing of meningeal and cutaneous pain information in the spinal Trigeminal Nucleus caudalis
    Cephalalgia, 2017
    Co-Authors: Celine Melin, Radhouane Dallel, Florian Jacquot, Nicolas Vitello, Alain Artola
    Abstract:

    IntroductionWithin superficial Trigeminal Nucleus caudalis (Sp5C) (laminae I/II), meningeal primary afferents project exclusively to lamina I, whereas nociceptive cutaneous ones distribute in both lamina I and outer lamina II. Whether such a relative absence of meningeal inputs to lamina II represents a fundamental difference from cutaneous pathways in the central processing of sensory information is still unknown.MethodsWe recorded extracellular field potentials in the superficial Sp5C of anesthetised rats evoked by electrically stimulating the dura mater, to selectively assess the synaptic transmission between meningeal primary afferents and second-order Sp5C neurons, the first synapse in trigeminovascular pathways. We tested the effect of systemic morphine and local glycinergic and GABAAergic disinhibition.ResultsMeningeal stimulation evokes two negative field potentials in superficial Sp5C. The conduction velocities of the activated primary afferents are within the Aδ- and C-fibre ranges. Systemic mor...

  • Bilateral Descending Hypothalamic Projections to the Spinal Trigeminal Nucleus Caudalis in Rats
    PloS one, 2013
    Co-Authors: Khaled Abdallah, Radhouane Dallel, Alain Artola, Lénaïc Monconduit, Philippe Luccarini
    Abstract:

    Several lines of evidence suggest that the hypothalamus is involved in Trigeminal pain processing. However, the organization of descending hypothalamic projections to the spinal Trigeminal Nucleus caudalis (Sp5C) remains poorly understood. Microinjections of the retrograde tracer, fluorogold (FG), into the Sp5C, in rats, reveal that five hypothalamic nuclei project to the Sp5C: the paraventricular Nucleus, the lateral hypothalamic area, the perifornical hypothalamic area, the A11 Nucleus and the retrochiasmatic area. Descending hypothalamic projections to the Sp5C are bilateral, except those from the paraventricular Nucleus which exhibit a clear ipsilateral predominance. Moreover, the density of retrogradely FG-labeled neurons in the hypothalamus varies according to the dorso-ventral localization of the Sp5C injection site. There are much more labeled neurons after injections into the ventrolateral part of the Sp5C (where ophthalmic afferents project) than after injections into its dorsomedial or intermediate parts (where mandibular and maxillary afferents, respectively, project). These results demonstrate that the organization of descending hypothalamic projections to the spinal dorsal horn and Sp5C are different. Whereas the former are ipsilateral, the latter are bilateral. Moreover, hypothalamic projections to the Sp5C display somatotopy, suggesting that these projections are preferentially involved in the processing of meningeal and cutaneous inputs from the ophthalmic branch of the Trigeminal nerve in rats. Therefore, our results suggest that the control of Trigeminal and spinal dorsal horn processing of nociceptive information by hypothalamic neurons is different and raise the question of the role of bilateral, rather than unilateral, hypothalamic control.

  • both oral and caudal parts of the spinal Trigeminal Nucleus project to the somatosensory thalamus in the rat
    European Journal of Neuroscience, 2005
    Co-Authors: Nathalie Guy, Radhouane Dallel, Maryse Chalus, Daniel L Voisin
    Abstract:

    Recent evidence has been accumulated that not only spinal Trigeminal Nucleus caudalis (Sp5C) neurons but also spinal Trigeminal Nucleus oralis (Sp5O) neurons respond to noxious stimuli. It is unknown, however, whether Sp5O neurons project to supraTrigeminal structures implicated in the sensory processing of orofacial nociceptive information. This study used retrograde tracing with Fluorogold in rats to investigate and compare the projections from the Sp5O and Sp5C to two major thalamic nuclei that relay ascending somatosensory information to the primary somatic sensory cortex: the ventroposteromedial thalamic Nucleus (VPM) and the posterior thalamic nuclear group (Po). Results not only confirmed the existence of contralateral projections from the Sp5C to the VPM and Po, with retrogradely labelled neurons displaying a specific distribution in laminae I, III and V, they also showed consistent and similar numbers of retrogradely labelled cell bodies in the contralateral Sp5O. In addition, a topographic distribution of VPM projections from Sp5C and Sp5O was found: neurons in the dorsomedial parts of Sp5O and Sp5C projected to the medial VPM, neurons in the ventrolateral Sp5O and Sp5C projected to the lateral VPM, and neurons in intermediate parts of Sp5O and Sp5C projected to the intermediate VPM. All together, these data suggest that not only the Sp5C, but also the Sp5O relay somatosensory orofacial information from the brainstem to the thalamus. Furthermore, trigemino-VPM pathways conserve the somatotopic distribution of primary afferents found in each subNucleus. These results thus improve our understanding of Trigeminal somatosensory processing and help to direct future electrophysiological investigations.

  • Organization of parabrachial projections from the spinal Trigeminal Nucleus oralis: an anterograde tracing study in the rat
    The Journal of comparative neurology, 2004
    Co-Authors: Radhouane Dallel, Olivier Ricard, Patrick Raboisson
    Abstract:

    In recent years, we have accumulated data showing that the spinal Trigeminal Nucleus oralis (Sp5O) contributes to the processing of somatosensory inputs from the orofacial region. Although the parabrachial area (PB) represents the main brainstem relay for autonomic, nociceptive, and gustatory afferents, few data are available regarding the topographical distribution of the efferent projections from the Sp5O to the PB. We have addressed this question with the rat, by using the anterograde tracer Phaseolus vulgaris leucoagglutinin. A dense trigeminoparabrachial pathway from the Sp5O toward, predominantly, the ipsilateral PB was revealed. Projections come mainly from the dorsal part of the Sp5O that was found to innervate densely the medial, external medial, and ventral lateral subnuclei. In contrast, the ventral part of the Sp5O projected almost exclusively to an as yet not formally described region, located dorsally and laterally to the lateral tip of the brachium conjunctivum, close to the Kolliker-Fuse Nucleus. These results suggest that distinct regions within the Sp5O may be involved in the processing of gustatory and nociceptive information.

  • Organization of diencephalic projections from the spinal Trigeminal Nucleus oralis: An anterograde tracing study in the rat
    Neuroscience, 2004
    Co-Authors: Ingrid De Chazeron, Patrick Raboisson, Radhouane Dallel
    Abstract:

    The organization of the efferent projections from the spinal Trigeminal Nucleus oralis (Sp5O) to the dienceph-alon was studied in the rat using the anterograde tracer Phaseolus vulgaris leucoagglutinin. The present study confirms the existence of trigemino-thalamic pathways originating from the Sp5O and details their distribution. The main diencephalic targets of the Sp5O are the ventral posterome-dial thalamic Nucleus (VPM), the posterior thalamic nuclei (Po) and the ventral part of the zona incerta (ZIv), contralat-erally, and the parvicellular part of the ventral posterior tha-lamic Nucleus (VPpc), bilaterally. The distribution of these projections varies according to the dorso-ventral location of the injection sites: the dorsal part of the Sp5O projects to the medial part of the VPM and the Po, and to the caudal part of the ZIv, as well as to the VPpc. The ventral part of the Sp5O projects to the lateral part of the VPM and the Po and to the rostral part of the ZIv. These results suggest that the tri-gemino-diencephalic pathways originating from the Sp5O are involved in the processing of gustatory and somatosensory information.

B Kerdelhue - One of the best experts on this subject based on the ideXlab platform.

  • cgrp in the Trigeminal Nucleus spinal cord and hypothalamus effect of gonadal steroids
    Neuropeptides, 1996
    Co-Authors: Saliha Moussaoui, Pierre Duval, V Lenoir, Claude Garret, B Kerdelhue
    Abstract:

    Calcitonin gene-related peptide (CGRP) contents were assayed in cervical spinal cord, Trigeminal Nucleus and hypothalamus throughout the estrous cycle and in male and ovariectomized rats. In the Trigeminal Nucleus, neither testosterone nor 17β-estradiol seem to affect CGRP accumulation, but progesterone seems to decrease it. In the cervical spinal cord, ovarian steroids seem to decrease CGRP while testosterone does not seem to influence it. In the hypothalamus, CGRP was only detectable in the male rat suggesting a positive effect of testosterone. It had marked circadian rhythm. In conclusion, CGRP content appears to be affected by gonadal steroids in the hypothalamus, the cervical spinal cord and the Trigeminal Nucleus in the rat.

  • substance p and neurokinin a variations throughout the rat estrous cycle comparison with ovariectomized and male rats ii Trigeminal Nucleus and cervical spinal cord
    Journal of Neuroscience Research, 1996
    Co-Authors: Pierre Duval, Saliha Moussaoui, V Lenoir, Claude Garret, B Kerdelhue
    Abstract:

    Substance P and neurokinin A were assayed in the Trigeminal Nucleus and cervical spinal cord of 4-day cycling female, ovariectomized, and male rats. During the estrous cycle, levels were largely stable in the Trigeminal Nucleus. In ovariectomized rats, the levels differed from those on any day of the estrous cycle suggesting a weak effect of ovarian steroids. In males, the variations in the substance P and neurokinin A contents in the Trigeminal Nucleus were not similar to those in either cyclic or ovariectomized rats. The levels fluctuated substantially in the cervical spinal cord. During the first 3 days of the estrous cycle, the substance P and neurokinin A contents fell concomitant with the 17 beta-estradiol surge, suggesting a downregulation of substance P and neurokinin A contents by 17 beta-estradiol. Furthermore, on estrus, progesterone seemed to inhibit the accumulation of both neurokinins. Testosterone may stimulate accumulation of substance P and neurokinin A in the cervical spinal cord, with a marked circadian rhythm. These results are in favor of the neurokinin content of the spinal cord being regulated by the gonadal steroids. In the Trigeminal Nucleus, only testosterone has an effect.

Toshio Terashima - One of the best experts on this subject based on the ideXlab platform.

  • Distribution of mesencephalic Trigeminal Nucleus neurons in the reeler mutant mouse.
    The Anatomical record, 1996
    Co-Authors: Toshio Terashima
    Abstract:

    Background Reeler (gene symbol, rl) is an autosomal recessive mutation occurring in mice and characterized by the abnormal positioning of neurons in the central nervous system. In this mutant, however, the cytoarchitecture of the peripheral nervous system is normal, implying that the reeler genetic locus does not affect migration of neurons in the peripheral system. Mesencephalic Trigeminal Nucleus (Me5) neurons are unique in that they are derived from the neural crest like other neurons in the peripheral nervous system, but enter secondarily into the central nervous system. Materials and Methods Me5 neurons were labeled by injecting horseradish peroxidase or Fast Blue into the temporal muscle of normal and reeler mice to determine whether the migration of these neurons is affected by the reeler genetic locus. Results and Conclusions Labeled Me5 neurons of the reeler mouse were more widely scattered in comparison with their normal counterparts, suggesting that the reeler genetic locus affects migration of neurons which originate in the neural crest and then migrate into the central nervous system. © 1996 Wiley-Liss, Inc.

  • Musculotopic organization in the motor Trigeminal Nucleus of the reeler mutant mouse
    Brain research, 1994
    Co-Authors: Toshio Terashima, Yasuko Kishimoto, Tomoyo Ochiishi
    Abstract:

    We examined the musculotopic organization in the motor Trigeminal Nucleus and the somatotopical arrangement in the Trigeminal ganglion of the normal and reeler mice. To determine whether or not masticatory motoneurons are malpositioned in the reeler mouse, we injected horseradish peroxidase (HRP) into the masticatory muscles of normal and reeler mice. Injections of HRP into the jaw-closing muscles, i.e., the masseter and temporalis muscles, labeled large multipolar neurons in the dorsolateral division of the motor Trigeminal Nucleus of both normal and reeler mice. Similar injections into the jaw-opening muscles, i.e., the anterior belly of the digastric muscle and mylohyoid muscle, labeled large multipolar neurons in the ventromedial division of the motor Trigeminal Nucleus of both mouse strains. Thus, the normal myotopical arrangement of the masticatory muscles on the motor Trigeminal Nucleus is preserved in the reeler mouse. However, detailed analysis revealed that jaw-opening motoneurons were more widely scattered in the reeler mouse than in the normal control. To examine the somatotopical arrangement of the first-order sensory neurons in the Trigeminal ganglion of the normal and reeler mice, we subcutaneously injected Fast blue (FB) into the mental region and Diamidino yellow (DY) into the vibrissal region of the same animals. No differences in distribution patterns of FB-labeled and DY-labeled neurons in the whole-mounted Trigeminal ganglion could been seen between these two strains, suggesting that migration of Trigeminal ganglion cells, which are derived from the neural crest and placode, is not deranged by the reeler genetic locus.

Xiu Yun - One of the best experts on this subject based on the ideXlab platform.

  • Action potential-triggered somatic exocytosis in mesencephalic Trigeminal Nucleus neurons in rat brain slices
    journal of physiology london, 2012
    Co-Authors: Bo Zhang, Pi-fu Luo, Liu Tao, Zhang Xiao-yu, Huang Wei, Zhu Fei-peng, Wu Qi-hui, Lu Jin, Xiu Yun
    Abstract:

    The neurons in the mesencephalic Trigeminal Nucleus (MeV) play essential roles in proprioceptive sensation of the face and oral cavity. The somata of MeV neurons are generally assumed to carry out neuronal functions but not to play a direct role in synaptic transmission. Using whole-cell recording and membrane capacitance (C-m) measurements, we found that the somata of MeV neurons underwent robust exocytosis (C-m jumps) upon depolarization and with the normal firing of action potentials in brain slices. Both removing [Ca2+](o) and buffering [Ca2+](i) with BAPTA blocked this exocytosis, indicating that it was completely Ca2+ dependent. In addition, an electron microscopic study showed synaptic-like vesicles approximated to the plasma membrane in somata. There was a single Ca2+-dependent releasable vesicle pool with a peak release rate of 1912 fF s(-1). Importantly, following depolarization-induced somatic exocytosis, GABA-mediated postsynaptic currents were transiently reduced by 31%, suggesting that the somatic vesicular release had a retrograde effect on afferent GABAergic transmission. These results provide strong evidence that the somata of MeV neurons undergo robust somatic secretion and may play a crucial role in bidirectional communication between somata and their synaptic inputs in the central nervous system.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000300685900012&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701NeurosciencesPhysiologySCI(E)CPCI-S(ISTP)PubMed8ARTICLE4753-76259

Noboru Mizuno - One of the best experts on this subject based on the ideXlab platform.