The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
G. Grant - One of the best experts on this subject based on the ideXlab platform.
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transganglionic transport and binding of the isolectin b4 from griffonia simplicifolia i in rat primary sensory neurons
Neuroscience, 1994Co-Authors: H F Wang, Brita Robertson, C Riveromelian, G. GrantAbstract:The isolectin B4 from Griffonia simplicifolia I binds to a subpopulation of rat small-diameter dorsal root ganglion neurons, and to fibres and presumed terminals in laminae I–II of the spinal cord dorsal horn. In the present study we investigated B4 and B4 conjugated to Horseradish peroxidase as potential transganglionic tracers of somatic primary afferent neurons after injection into a peripheral nerve. We also tried to identify the specific subpopulation of dorsal root ganglion neurons that bind and transport B4. Following injection of B4 or B4-Horseradish peroxidase into the sciatic nerve, labelled presumed terminals that reached peak labelling at two days were found exclusively in regions of the spinal cord gray matter known to receive unmyelinated primary afferent fibres. Almost all dorsal root ganglion cells that transported B4-Horseradish peroxidase also bound B4. Cell counts showed that 51% of the dorsal root ganglion neurons were B4-positive and cell area measurements that these were all in the small size range. An extensive overlap was found between B4 and fluoride-resistant acid phosphatase (85%), and between B4 and calcitonin gene-related peptide (59%). Seventeen per cent of the B4-positive cells were substance P-immunoreactive and 9% were immunoreactive to somatostatin. Minimal overlap was seen between B4-positive cells and cells positive for RT97 (3%), a selective marker of primary afferent neurons with myelinated axons. All somatostatin-immunoreactive cells and almost all (95%) of the fluoride-resistant acid phosphatase-positive cells were contained within the B4-positive population. This comprised also 58% of the cells immunoreactive to calcitonin gene-related peptide and 42% of those immunoreactive to substance P. The results obtained show that B4 binds to a subpopulation of unmyelinated primary afferent neurons, and that B4 and B4-Horseradish peroxidase can be used as selective transganglionic tracers of this specific cell subpopulation.
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projection patterns of primary sensory neurons studied by transganglionic methods somatotopy and target related organization
Brain Research Bulletin, 1993Co-Authors: G. GrantAbstract:The anatomical organization of the centrally projecting branches of different peripheral sensory nerves was not possible to investigate efficiently until the development of the axonal tracing methods. Horseradish peroxidase applied peripherally could be visualized in central projection areas provided a sensitive histochemical method was used; this created the basis for transganglionic tracing from the periphery. This has permitted the investigation of large-scale projections from peripheral sensory nerves. The use of conjugates of Horseradish peroxidase and lectins with affinities for different populations of primary sensory neurons, as well as the use of different postoperative survival times, has offered the possibility for selective visualization of projections from subsets of primary sensory neurons. For detailed studies of single afferent fiber projections, a combined physiological-anatomical approach using single-unit recording followed by intraaxonal application of Horseradish peroxidase, has become the method of choice. This chapter will focus on results which have been achieved by transganglionic tracing methods, in regard to the organization of the central projections of peripheral sensory nerves.
Luis Puelles - One of the best experts on this subject based on the ideXlab platform.
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reciprocal connections between the rabbit suprageniculate pretectal nucleus and the superior colliculus tracer study with Horseradish peroxidase and fluorogold
Visual Neuroscience, 1994Co-Authors: Carolina Lagares, Maria Caballerobleda, B Fernández, Luis PuellesAbstract:Connections of the rabbit suprageniculate pretectal nucleus (SP) with the superior colliculus were explored by means of retrograde transport of Horseradish peroxidase or Fluorogold. Large injections centered in the superficial and intermediate tectal layers resulted in bilateral retrograde transport to the medium-size multipolar neurons of the suprageniculate pretectal nucleus. Horseradish peroxidase was also transported anterogradely into the ipsilateral and contralateral neuropiles of the suprageniculate pretectal nucleus. The labeled cells in SP were dispersed throughout the nucleus, including its dorsal, wedge-shaped, internal portion. Labeling was mainly ipsilateral, and less abundant on the contralateral side.
Dean Dessem - One of the best experts on this subject based on the ideXlab platform.
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jaw muscle spindle afferent pathways to the trigeminal motor nucleus in the rat
The Journal of Comparative Neurology, 2001Co-Authors: Pifu Luo, Masayuki Moritani, Dean DessemAbstract:Neural pathways conveying proprioceptive feedback from the jaw muscles were studied in rats by combining retrograde and intracellular neuronal labeling. Initially, Horseradish peroxidase was iontophoresed unilaterally into the trigeminal motor nucleus (Vmo). Two days later, 1-5 jaw-muscle spindle afferent axons located in the mesencephalic trigeminal nucleus were physiologically identified and intracellularly stained with biotinamide. Stained mesencephalic trigeminal jaw-muscle spindle afferent axon collaterals and boutons were predominantly distributed in the supratrigeminal region (Vsup), Vmo, dorsomedial trigeminal principal sensory nucleus (Vpdm), parvicellular reticular formation (PCRt), alpha division of the parvicellular reticular formation (PCRtA), and dorsomedial portions of the spinal trigeminal subnuclei oralis (Vodm), and interpolaris (Vidm). Numerous neurons retrogradely labeled with Horseradish peroxidase from the trigeminal motor nucleus were found bilaterally in the PCRt, PCRtA, Vodm, and Vidm. Retrogradely labeled neurons were also present contralaterally in the Vsup, Vpdm, Vmo, peritrigeminal zone, and bilaterally in the dorsal medullary reticular field. Putative contacts between intracellularly stained mesencephalic trigeminal jaw-muscle spindle afferent boutons and trigeminal premotor neurons retrogradely labeled with Horseradish peroxidase were found in the ipsilateral Vodm, PCRtA, and PCRt, as well as the contralateral Vsup, Vmo, Vodm, PCRt, and PCRtA. Thus, multiple disynaptic jaw-muscle spindle afferent-motoneuron circuits exist. These pathways are likely to convey long-latency jaw-muscle stretch reflexes and may contribute to stiffness regulation of the masticatory muscles.
Shaojun Dong - One of the best experts on this subject based on the ideXlab platform.
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a method to construct a third generation Horseradish peroxidase biosensor self assembling gold nanoparticles to three dimensional sol gel network
Analytical Chemistry, 2002Co-Authors: Bingquan Wang, Aiguo Wu, Guangjin Cheng, Zhuang Li, Shaojun DongAbstract:A novel method for fabrication of Horseradish peroxidase biosensor has been developed by self-assembling gold nanoparticles to a thiol-containing sol−gel network. A cleaned gold electrode was first immersed in a hydrolyzed (3-mercaptopropyl)-trimethoxysilane (MPS) sol−gel solution to assemble three-dimensional silica gel, and then gold nanoparticles were chemisorbed onto the thiol groups of the sol−gel network. Finally, Horseradish peroxidase (HRP) was adsorbed onto the surface of the gold nanoparticles. The distribution of gold nanoparticles and HRP was examined by atomic force microscopy (AFM). The immobilized Horseradish peroxidase exhibited direct electrochemical behavior toward the reduction of hydrogen peroxide. The performance and factors influencing the performance of the resulting biosensor were studied in detail. The resulting biosensor exhibited fast amperometric response (2.5 s) to H2O2. The detection limit of the biosensor was 2.0 μmol L-1, and the linear range was from 5.0 μmol L-1 to 10.0 m...
Anton Glieder - One of the best experts on this subject based on the ideXlab platform.
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MINI-REVIEW An updated view on Horseradish peroxidases: recombinant production and biotechnological applications
2016Co-Authors: Florian W. Krainer, Anton GliederAbstract:peroxidase has been the subject of sci-entific research for centuries. It has been used exhaustively as reporter enzyme in diagnostics and histochemistry and still plays a major role in these applications. Numerous studies have been conducted on the role of Horseradish peroxidase in the plant and its catalytic mechanism. However, little prog-ress has been made in its recombinant production. Until now, commercial preparations of Horseradish peroxidase are still isolated from plant roots. These preparations are commonly mixtures of various isoenzymes of which only a small fraction has been described so far. The composition of isoenzymes in these mixed isolates is subjected to uncontrollable environ-mental conditions. Nowadays, Horseradish peroxidase regains interest due to its broad applicability in the fields of medicine, life sciences, and biotechnology in cancer therapy, biosensor systems, bioremediation, and biocatalysis. These medically and commercially relevant applications, the recent discovery of new natural isoenzymes with different biochemical proper-ties, as well as the challenges in recombinant production ren-der this enzyme particularly interesting for future biotechno-logical solutions. Therefore, we reviewed previous studies as well as current developments with biotechnological emphasis on new applications and the major remaining biotechnological challenge—the efficient recombinant production of horserad-ish peroxidase enzymes
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An updated view on Horseradish peroxidases: recombinant production and biotechnological applications
Applied Microbiology and Biotechnology, 2015Co-Authors: Florian W. Krainer, Anton GliederAbstract:Horseradish peroxidase has been the subject of scientific research for centuries. It has been used exhaustively as reporter enzyme in diagnostics and histochemistry and still plays a major role in these applications. Numerous studies have been conducted on the role of Horseradish peroxidase in the plant and its catalytic mechanism. However, little progress has been made in its recombinant production. Until now, commercial preparations of Horseradish peroxidase are still isolated from plant roots. These preparations are commonly mixtures of various isoenzymes of which only a small fraction has been described so far. The composition of isoenzymes in these mixed isolates is subjected to uncontrollable environmental conditions. Nowadays, Horseradish peroxidase regains interest due to its broad applicability in the fields of medicine, life sciences, and biotechnology in cancer therapy, biosensor systems, bioremediation, and biocatalysis. These medically and commercially relevant applications, the recent discovery of new natural isoenzymes with different biochemical properties, as well as the challenges in recombinant production render this enzyme particularly interesting for future biotechnological solutions. Therefore, we reviewed previous studies as well as current developments with biotechnological emphasis on new applications and the major remaining biotechnological challenge—the efficient recombinant production of Horseradish peroxidase enzymes.