PubMed Health⌕ Search

Biomedical subjects

C H Berthold

Publications and source records attributed to C H Berthold.

At least 55 records · Page 3Linked to original sources
PubMed1986

Peroxidase activity at nodes of ranvier in lumbosacral ventral spinal roots and in the PNS-CNS transitional region after intramuscular administration of horseradish peroxidase.

The axoplasm of nodes of Ranvier in feline lumbosacral ventral spinal roots was analysed by light and electron microscopy 18-168 h after the injection of horseradish peroxidase (HRP) into the medial gastrocnemius muscle. Three main HRP distribution patterns were distinguished at PNS nodes (bordered by Schwann cells only) of large fibres transporting HRP. The type A pattern, characterized by a distal accumulation of HRP-positive bodies and a proximal system of vesiculotubular membrane profiles. The incidence of this type of node was highest at relatively short survival times. The type B pattern, which appeared somewhat later, resembled the type A node with the addition of a disc-like, proximal accumulation of HRP activity. The type C pattern which contained scattered HRP-positive bodies and delicate strands of membraneous profiles, dominated 72 h after injection. The number of HRP-positive PNS-CNS borderline nodes (bordered by both Schwann cells and glial cells) was less than 5% of the corresponding value in the same fibres of the ventral root proper. A highly segregated state of the axoplasm of PNS-CNS borderline nodes was noted only in two cases. The observations indicate a functional difference between nodal axoplasm at the PNS-CNS borderline and nodal axoplasm in the PNS part of the alpha motor neuron.

Animals↗
PubMed1986

Peroxidase activity at consecutive nodes of Ranvier in the nerve to the medial gastrocnemius muscle after intramuscular administration of horseradish peroxidase.

The distribution of axoplasmic organelles at consecutive nodes of Ranvier was investigated light- and electronmicroscopically in horseradish peroxidase-transporting muscle nerve fibres of the adult cat. Three main and apparently temporally interrelated distribution patterns were noted. These patterns were referred to as A, B and C. The axoplasm of type-A and type-B nodes was highly segregated with regard to the proximodistal distribution of certain organelles. At type-A nodes horseradish peroxidase-positive membrane limited bodies and horseradish peroxidase-negative vesiculotubular membrane profiles were accumulated just distal and just proximal to the nodal mid-level, respectively. At B nodes a disc-like accumulation of enzyme activity, that was situated a few micron proximal to the mid-level, added to the type-A pattern. The type-C node showed a barely segregated axoplasm in which horseradish peroxidase-positive bodies were distributed randomly. We suggest, on the basis of the mutual order of the nodal types in a sequence of consecutive nodes and their appearance relative to the time after the administration of the HRP, that the different axoplasmic patterns reflect the operation of an ordered process that delays part of the retrogradely transported HRP for 2-3 days. The large number of lysosome-like HRP positive bodies that appeared at the nodes during this process indicates that the nodal axoplasm not only delays but also might take part in the degradation of the foreign protein.

Acid Phosphatase↗
PubMed1985

Peroxidase activity at nodes of Ranvier in some commonly used laboratory animals after intramuscular administration of horseradish peroxidase.

During retrograde transport of intramuscularly administrated horseradish peroxidase (HRP) nodal axon segments of rabbit, rat, and mouse peripheral nerve fibers became HRP-positive and showed a striking proximodistal segregation of certain axoplasmic organelles. HRP-positive bodies and HRP-negative vesiculotubular membrane profiles were seen just distal and proximal to the nodal midlevel, respectively. This appearance was similar to that found earlier in HRP-transporting feline muscle nerve fibers. Some mechanisms that might explain the segregated appearance are briefly discussed.

Animals↗
PubMed1984

Ultrastructural morphometric studies on regeneration of the lateral sural cutaneous nerve in the white rat after transection of the sciatic nerve.

The lateral sural cutaneous nerves of 49 Sprague-Dawley rats 7-76 weeks of age were examined morphometrically in single transverse sections using electron microscopy. The following variables were estimated: the relative proportions of collagen-occupied and collagen-free areas of the extracellular compartment of the endoneurial space, the number and the diameters of axons, the number of myelin lamellae, and the number of different kinds of cell nuclei. The nerve contained on the average 2600 axons of which about 2200 (85%) were unmyelinated. The different variables were computed with regard to the animal-to-animal, side-to-side, and age variations. From these data normal reference diagrams based on the 95% prediction intervals for individual observations were constructed. Animal-to-animal and side-to-side variations were of about the same magnitude except in cases where the variation was age-dependent. Prediction intervals for individual observations that were +/- 50-70% of the mean value were found for the numbers of different types of Schwann cell nuclei. The intervals for the number and mean diameters of unmyelinated axons and myelinated fibres was +/- 20-30%. The g-value showed the narrowest interval +/- 10%. Age-related variation was found for the transverse section area of the nerve, axon diameters, and the number of myelin sheath lamellae. The application of normal values as a reference system to experimental data is discussed.

Aging↗
PubMed1983

Sural nerve biopsies from workers with a history of chronic exposure to organic solvents and from normal control cases. Morphometric and ultrastructural studies.

An ultrastructural and morphometric study was performed on sural nerve biopsies of four industrial spray painters (35-59 years) and 11 controls (6-64 years). No difference could be shown in spray painters and age-matched controls as to the number of myelinated nerve fibres per area, their size distribution, variation of internodal length along single nerve fibres or the ratio between the number of myelin lamellae and the axon circumference. There was marked scattering of the two latter parameters in older exposed and and control individuals. The distribution of NADH2-tetrazolium reductase activity was similar in exposed and control cases. The general ultrastructural appearance of nodal-paranodal regions in controls conformed with that noted in experimental animals. The overall ultrastructural organization and age-related changes of nerves of exposed cases were similar to those of control cases except for a presence of paranodal axonal mitochondria which contained glycogen-like particles in exposed cases. In one exposed case abundant dispersed or clustered glycogen-like particles were seen in the paranodal axoplasm. These findings are suggested to be an effect of chronic exposure to organic solvent vapours. Ageing seems, however, to have a much greater impact on the morphology of the sural nerve fibre than occupational exposure to organic solvent.

Adult↗
PubMed1983

Electron microscopic serial section analysis of nodes of Ranvier in lumbosacral spinal roots of the cat: ultrastructural organization of nodal compartments in fibres of different sizes.

The general ultrastructural organization of nodes of Ranvier in peripheral nerve fibres from 2 to 20 microns in diameter (D) was investigated in the adult cat using serially sectioned ventral and dorsal spinal roots. The study was performed in order to collect and systematize information considered necessary for a morphometric analysis of the node of Ranvier. In all cases a node of Ranvier could be divided into a central nodal axon segment and a surrounding nodal Schwann cell compartment. The latter included a nodal gap matrix substance, more or less overlapping nodal Schwann cell collars and, as a rule, also a Schwann cell brush-border emanating from the nodal Schwann cell collars and occupying the nodal gap. The relative size and the organization level of the nodal Schwann cell compartment increased with increasing fibre size up to a fibre diameter of 8-10 microns. At this fibre size the nodal gap was of a fairly even height (1 micron) all around the nodal axon and contained a thick brush-border of densely packed, more or less radially arranged Schwann cell microvilli. In very small fibres (D less than 3 microns) the nodal gap was low (less than 0.1 microns) and contained no or few microvilli. In fibres greater than 10 microns in diameter the relative size and the degree of structural order of the nodal Schwann cell compartment decreased with increasing fibre size. Drastic sectorial variations in nodal gap height and local thinning-out of the brush-border became prominent features in the largest fibres. The possible in vivo organization of the nodal Schwann cell compartment is discussed. Preliminary calculations indicate that the extracellular space directly surrounding the nodal axon might be quite small and that the area open for free communication between this extracellular space and the endoneurial space might be very much restricted, measuring as little as 2% of the area of the nodal axolemma. Algorithms for calculating various nodal structural parameters are discussed.

Animals↗
PubMed1983

Electron microscopic serial section analysis of nodes of Ranvier in lumbar spinal roots of the cat: a morphometric study of nodal compartments in fibres of different sizes.

Serially sectioned nodes of Ranvier from nerve fibres 2-20 micron in diameter of feline ventral and dorsal spinal roots were examined electron microscopically, reconstructed to scale and analysed morphometrically. The assumed 'fresh-state' value of several structural variables, considered to be of functional significance, were calculated by the use of compensation factors. The compensated data were plotted against fibre and axon diameters. It was calculated that the membranous area of the 'fresh-state' nodal axon segment increased more or less exponentially from less than 5 micron2 to 30 micron2 with increasing fibre diameter (D). Most variables associated with the nodal gap and the Schwann cell initially increased rapidly with D and then levelled out or even decreased in fibres with a D value greater than 8-12 micron. The area open for communication between the nodal axolemma and the endoneurial space was 30-100 times smaller than the membrane area of the nodal axolemma. The volume of the extracellular space in the nodal gap, outside the nodal axolemma, increased linearly from less than 0.1 micron3 to about 0.6 micron3 with increasing fibre size. The Schwann cell membrane area facing the nodal gap outnumbered the membrane area of the nodal axon by 10-15 times in nerve fibres with a D value between 5 and 15 microns. Some functional implications of the 'fresh-state' nodal model are discussed.

Animals↗
PubMed1983

Axon diameter and myelin sheath thickness in nerve fibres of the ventral spinal root of the seventh lumbar nerve of the adult and developing cat.

The axon diameter (d) and the number of myelin sheath lamellae (nl) were estimated in electron micrographs of cross sectioned ventral spinal roots of the seventh lumbar nerve of adult cats, kittens and cat fetuses. Myelination started between the 40th and the 45th day after mating (about 3 weeks before birth). From birth onwards the calibre spectrum consisted of a group of small fibres and a group of large fibres. During the first two postnatal months the point distribution of the number of myelin lamellae plotted against the axon diameter appeared more or less linear. This point distribution pattern became curved from the 10th postnatal week onwards, and a function of the general expression: nl = C0 + C1d + C2 log(d) could be fitted to describe the regression. In adult cats, the mean number of myelin lamellae/axon diameter ratio was about 30 in the group of small and about 15 in the group of large fibres. Observations on immature animals indicated that the difference between the two fibre groups could have been established already during the third postnatal week. Considerable myelin production took place after the age of 1 year. The cross sectional area of the myelin sheath in the alpha fibre group increased about 10% after the age of 1 year, while in the gamma fibre group it increased as much as about 85%. The absolute amount of myelin per unit fibres. Differences and similarities between myelin production in the two fibre groups are discussed.

Animals↗
PubMed1982

Myelination of S1 dorsal root axons in the cat.

Samples of S1 dorsal root nerve fibers from cats of different pre- and postnatal ages were examined electron microscopically with regard to axon caliber and number of myelin lamellae. Each root was examined at four different cross-sectional levels. Two levels were situation close to the spinal cord entrance on each side of the peripheral (PNS) and central nervous system (CNS) border. The third and fourth levels were located more distally. The first compact myelin lamella was observed in the CNS part of the root in a 47-day-old fetus. In the 53-day-old fetus the degree of myelination was the same in the CNS as distal in the PNS part of the root. Surprisingly, all axons appeared unmyelinated close to the PNS-CNS border and remained so for a further 10-day period. After this time lag, this part of the root became myelinated and showed a rapid increase in myelin sheath thickness. Calculations of axonal growth, mesaxonal length, and myelin volume indicated a maturation process that progressed discontinuously. Myelination did not proceed in a strict somatofugal direction, but was a regionally differentiated process. The maximal myelin production, expressed as the increase in myelin volume per Schwann cell, was found during the second to fourth postnatal months, i.e., very late in development.

Age Factors↗
PubMed1982

Distribution of peroxidase activity at nodes of Ranvier after intramuscular administration of horseradish peroxidase in the cat.

The occurrence of intra-axonal peroxidase activity in large myelinated nerve fibres to the plantaris longus muscle of the cat was investigated histochemically 10-12 h after intramuscular administration of horseradish peroxidase. Internodal horseradish peroxidase activity was low. Its demonstration required electron microscopical analysis of serial sections. In contrast to this, many nodal regions did, even in the light-microscope, disclose a high and characteristically distributed horseradish peroxidase activity. At such nodes the distal part of the constricted axon segment was crowded with horseradish peroxidase-positive bodies of which several were of the so-called multivesicular type. The proximal part of the constricted axon segment was almost free of horseradish peroxidase-positive bodies and contained a densely-packed vesiculotubular membranous system. This striking polarization of the nodal axon region is discussed and tentatively interpreted as the consequence of a physiological damming-up of both somatofugally- and somatopetally-transported materials.

Animals↗
PubMed1982

Electron immunoperoxidase stainings in sections of unfixed pure cultures of Streptococcus mutans.

Unfixed as well as glutaraldehyde-fixed pelleted cells from pure cultures of Streptococcus mutans subspecies sobrinus (B13) were embedded in glycolmethacrylate. Ultrathin were sections immunoperoxidase labelled with rabbit anti-S. mutans sobrinus gamma-globulin. It was found that unfixed specimens became labelled as precisely and as distinctly as did the fixed specimens. All controls were negative.

Fixatives↗
PubMed1979

Electron microscopic studies of serially sectioned cat spinal alpha-motoneurons. I. Effects of microelectrode impalement and intracellular staining with the fluorescent dye "Procion Yellow".

Cat spinal alpha-motoneurons were studied in the light and electron microscope after intracellular recording and staining with the fluorescent dye Procion Yellow. Generally, the ultrastructural preservation of the stained neurons improved when the amount of dye delivered was decreased, and when the duration of the microelectrode impalement of the neuron as well as the time between the intracellular staining and the tissue fixation was kept as short as possible. Utilizing the optimal experimental procedure finally arrived at, about one-third of the stained neurons could be used for further quantitative morphometric analysis. With respect to synaptology and gross architecture these cells appeared to differ from control motoneurons mainly with regard to a focal disarrangement of the cell body periphery, probably a result of the microelectrode injury, and a certain degree of damage to some large boutons.

Animals↗
PubMed1979

Electron microscopic studies of serially sectioned cat spinal alpha-motoneurons. II. A method for the description of architecture and synaptology of the cell body and proximal dendritic segments.

The paper presents a method for ultrastructural analysis and description of neuronal architecture and synaptology of cat spinal alpha-motoneurons from complete series of consecutive ultrathin sections through the cell body and proximal parts of the dendrites. The method implies that sections are selected for analysis only at certain constant intervals in the series. The occurrence of boutons of different morphological types on the neuronal surface was expressed by their percentage covering of the neuronal membrane. The neuronal surface was divided into a number of compartments and the synaptic covering was calculated separately for each compartment. An interval of 6 micrometer between the sections was used for these calculations, and the obtained values for synaptic covering were found not to differ significantly from those obtained in controls at 3 micrometer intervals. The number and location of individual large boutons (C- and M-types) were studied at 3 micrometer section intervals, and the escape of boutons connected to this procedure was estimated from control observations at 1 micrometer intervals. It is concluded that detailed information on neuronal synaptology can be obtained with this method, which will be used in three subsequent studies on functionally identified and intracellularly stained cat alpha-motoneurons.

Animals↗
PubMed1979

Electron microscopic studies of serially sectioned cat spinal alpha-motoneurons. III. Motoneurons innervating fast-twitch (type FR) units of the gastrocnemius muscle.

Two intracellularly stained cat gastrocnemius alpha-motoneurons of the FR-type (Burke et al., '73) were studied ultrastructurally. The architecture and synaptology of the cell body and proximal parts of the dendrites were analyzed from a long series of consecutive sections, according to a method presented in a preceding paper (Conradi et al., '79a). Several of the dendrites had a base diameter exceeding 10 micrometer. The proportion of the surface covered by boutons was 40-50% for the cell body and about 80% for the proximal dendrites. In both regions, about 20% of the boutons were of the S-type and 70% of the F-type. The large C-boutons were clustered around the dendritic roots and were also present on the axon hillock. M-boutons of dorsal root origin were located on the proximal parts of the majority of the dendrites.

Animals↗