The Experts below are selected from a list of 1029 Experts worldwide ranked by ideXlab platform

Karl H. Pfenninger - One of the best experts on this subject based on the ideXlab platform.

Freire Miguel - One of the best experts on this subject based on the ideXlab platform.

  • New developments in an 'expanded stick' model for coding, graphic representation and metric analysis of tracer-filled or Golgi-impregnated neurons, including spines and varicosities
    2013
    Co-Authors: Freire Miguel
    Abstract:

    A new data model allowing the coding, graphic representation and metric analysis of dendritic and axonal processes including spines and varicosities, is here described. The model is implemented in an interactive light microscope-computer system and stores the three-dimensional coordinates of the selected neuronal points, their topological identifiers, and the width of the processes. In addition codes for 'nature', and 'shape' are stored in the data array. The 'nature' code identifies structures such as Perikaryon, axon, apical dendrite, basal dendrite, etc. The 'shape' code defines varicosities and spines and allows their graphic representation. At present, the coding for metric analysis is made at a final magnification of x1875, with a resolution of 0.11 μm in the objective plane. The graphic representation of spines and varicosities in an ellipse, whose major axis is the length of spines and varicosities and the minor axis the width of these structures. From this 'expanded stick' model a computer program calculates the length, area and form factor of the Perikaryon; the mean length, width and area of each neuronal branch; the distribution of varicosity and spine number and their size (length and width) per length interval; the total number of processes, varicosities and spines; and the total length and area of the processes.Peer Reviewe

  • Quantitative computer analysis of Golgi-impregnated neurons using a new 'expanded stick' model for coding; Its application to the study of axons
    2013
    Co-Authors: Freire Miguel
    Abstract:

    A computer program to obtain quantitative data from an expanded 'stick model' of the Golgi-impregnated neuron is described. The computer program allows complete three-dimensional morphometric analysis of neurons, including the size of varicosities and spines and their distribution on neuronal branches. Furthermore, the perimeter and area of the Perikaryon as well as the length, width and area of neuronal processes can be obtained. The use of this computer program is illustrated by coding two types of axons.Peer Reviewe

  • An 'expanded stick' model for coding Golgi-impregnated neuronal morphology
    2013
    Co-Authors: Freire Miguel
    Abstract:

    A new model for coding Golgi-impregnated neuronal morphology, which can be implemented in any computer-assisted optical microscope, is described. This model, in addition to storing the three-dimensional coordinates of the selected neuronal points and their topological identifiers, codes for 'width', 'nature', and 'shape'. Thee 'width' code digitizes the width of a neuronal process. The 'nature' code can identify structures such as Perikaryon, axon apical dendrite, basal dendrite, etc. The 'shape' code defines nodules and spines. Computer graphics routines are described for drawing nodules and spines as well as neuronal processes with 'width'.Peer Reviewe

  • Distribution of peripherally stained neurons by colloidal iron histochemical method in albino rat cerebral cortex. A quantitative study
    2013
    Co-Authors: Martínez-rodríguez Ricardo, Freire Miguel, Martínez-murillo Ricardo
    Abstract:

    A few stained neurons were demonstrated in several cortical areas by the Colloidal Iron method. The intense positive histochemical reaction was located surrounding the Perikaryon and some neuronal branches. A quantitative study demonstrated that the largest percentage of stained neurons was found in III, IV and V layers of the visual and auditory cortex. The number of stained neurons in the auditory cortex was greater than in the visual cortex. Statistically significant differences (Student's t-test) were obtained between layers I, II, III and VI of both cortical areas. In other cortical areas studied there were no stained neurons (area insularis ventralis, are entorhinalis and area piriformis).Peer Reviewe

  • Histochemical study on the distribution of glycoproteins and polyanionic substances in the cerebral cortex of the albino rat during post-natal development
    2013
    Co-Authors: Martínez-rodríguez Ricardo, Toledano Gasca Adolfo, Martínez-murillo Ricardo, Freire Miguel
    Abstract:

    The distribution of glycoproteins and polyanionic substances in the cerebral cortex of albino rats at different ages has been investigated. Observations showed that Alcian Blue and Colloidal Iron histochemical methods revealed the existence of scattered neurons with an intense positive histochemical reaction in the periphery of the Perikaryon and of the prolongations in the cerebral cortex of 36-day old rats, but not in younger rats. These special neurons can be observed in the auditory and visual cortex, but not in the piriformis cortex or in entorhinal area. It is considered that these neurons must be related in some way to specific functions of the cerebral cortex which begin at a certain stages of its development.Peer Reviewe

Adriana Estrada-bernal - One of the best experts on this subject based on the ideXlab platform.

John H. Carson - One of the best experts on this subject based on the ideXlab platform.

  • Transport and Localization of Exogenous Myelin Basic Protein mRNA Microinjected
    2013
    Co-Authors: Into Oligodendrocytes, Kevin Ainger, Daniela Avossa, Frank Morgan, Ra J. Hill, Christopher Barry, Elisa Barbarese, John H. Carson
    Abstract:

    Abstract. We have studied transport and localization of MBP mRNA in oligodendrocytes in culture by microinjecting labeled mRNA into living cells and analyzing the intracellular distribution of the injected RNA by confocal microscopy. Injected mRNA initially appears dispersed in the Perikaryon. Within minutes, the RNA forms granules which, in the case of MBP mRNA, are transported down the processes to the periphery of the cell where the distribution again becomes dispersed. In situ hybridization shows that endogenous MBP mRNA in oligodendrocytes also appears as granules in the Perikaryon and processes and dispersed in the peripheral membranes. The granules are not released by extraction with non-ionic detergent, indicating that they are associated with th

  • Transport and Localization Elements in Myelin Basic Protein mRNA
    2013
    Co-Authors: Kevin Ainger, Daniela Avossa, Christopher Barry, Elisa Barbarese, Amy S. Diana, John H. Carson
    Abstract:

    Abstract. Myelin basic protein (MBP) mRNA is localized to myelin produced by oligodendrocytes of the central nervous system. MBP mRNA microinjected into oligodendrocytes in primary culture is assembled into granules in the Perikaryon, transported along the processes, and localized to the myelin compartment. In this work, microinjection of various deleted and chimeric RNAs was used to delineate regions in MBP mRNA that are required for transport and localization in oligodendrocytes. The results indicate that transport requires a 21-nucleotide sequence, termed the RNA transport signal (RTS), in the 3 � UTR of MBP mRNA. Homologous sequences are present in several other localized mRNAs, suggesting that the RTS represents a general transport signal in a variety of different cel

  • transport and localization of exogenous myelin basic protein mrna microinjected into oligodendrocytes
    1993
    Co-Authors: Kevin Ainger, Daniela Avossa, Frank Morgan, Christopher Barry, Elisa Barbarese, Sandra J Hill, John H. Carson
    Abstract:

    We have studied transport and localization of MBP mRNA in oligodendrocytes in culture by microinjecting labeled mRNA into living cells and analyzing the intracellular distribution of the injected RNA by confocal microscopy. Injected mRNA initially appears dispersed in the Perikaryon. Within minutes, the RNA forms granules which, in the case of MBP mRNA, are transported down the processes to the periphery of the cell where the distribution again becomes dispersed. In situ hybridization shows that endogenous MBP mRNA in oligodendrocytes also appears as granules in the Perikaryon and processes and dispersed in the peripheral membranes. The granules are not released by extraction with non-ionic detergent, indicating that they are associated with the cytoskeletal matrix. Three dimensional visualization indicates that MBP mRNA granules are often aligned in tracks along microtubules traversing the cytoplasm and processes. Several distinct patterns of granule movement are observed. Granules in the processes undergo sustained directional movement with a velocity of approximately 0.2 micron/s. Granules at branch points undergo oscillatory motion with a mean displacement of 0.1 micron/s. Granules in the periphery of the cell circulate randomly with a mean displacement of approximately 1 micron/s. The results are discussed in terms of a multi-step pathway for transport and localization of MBP mRNA in oligodendrocytes. This work represents the first characterization of intracellular movement of mRNA in living cells, and the first description of the role of RNA granules in transport and localization of mRNA in cells.

Kirk C. Hansen - One of the best experts on this subject based on the ideXlab platform.