bluuebunny/crossref_metadata_2025 huggingface dataset:
ENHANCED PERMEABILITY TO HORSERADISH PEROXIDASE ACROSS CEREBRAL VESSELS IN THE RAT AFTER PORTOCAVAL ANASTOMOSIS
Authors: LAURSEN H. , WESTERGAARD E.
Published: May 2008

The blood—brain barrier to horseradish peroxidase (HRP) was examined in rats 10 or 30 days after establishing an end‐to‐side portocaval anastomosis. An increased number of vesicles containing HRP were seen in the endothelial cells of arterioles and to a lesser degree in the endothelial cells of venules and capillaries. Peroxidase was not found in the interendothelial space between tight junctions, which were everywhere intact. The basement membranes of vessels and the neuropil adjacent to these could contain the tracer. Astrocytic endfeet were swollen 10 days after the operation and contained only a few organelles. Thirty days after the operation reactive changes seemed to occur in astrocytes, indicated by less swelling and enhanced number of organelles. The cytoplasm of the astrocytes in some instances was evenly stained by reaction product. A similar staining was very occasionally observed in a few neuronal processes. It is concluded that an increased vesicular transport of HRP is inferred to have occurred across cerebral endothelium in animals after PCA and that the astrocytes may be especially sensitive to damage to the plasma membrane during liver shunt encephalopathy leading to intra‐cellular uptake of substances from the extracellular space.
POLYNEUROPATHIES AND CNS PROTEIN METABOLISM. II. CHANGES IN THE INCORPORATION RATE OF LEUCINE DURING ACRYLAMIDE INTOXICATION
Authors: SCHOTMAN P. , GIPON L. , JENNEKENS F. G. I. , GISPEN W. H.
Published: May 2008

The hypothesis of failure of neuronal cell body metabolism as the principal cause of acrylamide neuropathy is re‐examined. Protein synthesis was studied in rats during chronic intoxication with acrylamide in spinal cord, brain stem and heart during three phases of the intoxication. The incorporation of radioactivity into proteins was measured in vivo after injection of radioactive leucine or after incubation in vitro of tissue slices with the labelled precursor. A highly significant depression of incorporation of precursor was found which suggests a relation between the rate of incorporation of amino acids into protein and progress of acrylamide neuropathy.
MYELINATION OF THE OVINE CNS WITH SPECIAL REFERENCE TO BORDER DISEASE. II. QUANTITATIVE ASPECTS*
Authors: BARLOW R. M. , STOREY I. JANICE
Published: May 2008

Myelination of the ovine CNS with special reference to Border disease. II. Quantitative aspects

Semithin Araldite sections and electron micrographs of the dorsal funiculus of spinal cord of sheep fetuses have been examined by methods devised to quantitate certain aspects of myelination. The data relating to axon size and shape, numbers of myelin lamellae, numbers and types of glial cells in normal fetuses have been compared with similar data obtained from an age‐matched series of fetuses affected with Border disease (BD). It was found that the enlargement of axons normally associated with the initial phases of myelination was greater in affected fetuses and, together with the accompanying irregularities of profile, tended to persist throughout gestation. In BD fetuses the rate and degree of myelination was reduced and the high periodicity which characterizes early myelin persisted into late gestation. Mature oligodendrocytes in BD fetuses were reduced by up to 40%, the normal total complement of glial cells being made up by cells with the morphology of multipotential (Type III) glial cells. It is tentatively concluded that Border disease affects the differentiation of oligodendrocytes from their precursors and thus leads to reduced myelin formation. Border disease is compared with relevant experimental and natural conditions and some similarities with Quaking in the mouse are indicated.
LONGTERM INFECTION OF CULTURED HAMSTER DORSAL ROOT GANGLIA WITH HALLÉ SSPE VIRUS
Authors: ECOB‐JOHNSTON MARION S. , BORNSTEIN M. B. , RAINE C. S.
Published: May 2008

Longterm infection of cultured hamster dorsal root ganglia with Hallé SSPE virus

The morphogenesis of Hallé SSPE virus in cultures of hamster dorsal root ganglia (DRG) over a period of 60 days was followed by light and electron microscopy and by immunoperoxidase techniques. The Hallé virus was originally isolated from the lymph node of a patient with SSPE, and had been passaged only in non‐neural cell lines. In organotypic cultures of hamster DRG, all cells except the neurons became infected. Large intracytoplasmic and intranuclear inclusions were commonly found in fibroblasts, but never in Schwann cells. The latter cells rounded up and were lost from the culture by 20 days post‐infection (PI). Cell‐free virus was detected by 7 days PI, reached a maximum at 30–40 days PI, and even at 60 days PI, substantial amounts of virus were still recorded. Budding virus particles were seen throughout the course of the infection. The formation of syncytia was rare. The present results are compared with previous data on the growth of measles virus in hamster DRG, and the growth of measles and SSPE viruses in cultures of hamster cerebellum. It was concluded that among the available strains of SSPE and measles virus, the Hallé strain is unique in its failure to infect nerve cells.
THE DISTRIBUTION AND ROLE OF MICROTUBULES AND FILAMENTS IN THE NEOPLASTIC ASTROCYTES OF EXPERIMENTAL GLIOMAS
Authors: LANTOS P. L.
Published: May 2008

The distribution and role of microtubules and filaments in the neoplastic astrocytes of experimental gliomas

Neoplasms of the nervous system were induced transplacentally by giving N‐ethyl‐N‐nitrosourea (ENU) to pregnant rats on the 15th day of gestation. Astrocytomas and mixed gliomas with a significant astrocytic component were selected in order to study the distribution of microtubules and filaments in neoplastic fibrillary astrocytes. Electron microscopy of these gliomas revealed a population of pleomorphic astrocytes at various stages of differentiation. Poorly differentiated neoplastic astrocytes showed many microtubules but few filaments. In moderately differentiated cells there was a decrease in the number of microtubules with a concurrent increase of filaments. In well differentiated neoplastic astrocytes filaments dominated the cytoplasm forming thick, tightly packed bundles at the periphery of the cells and in the large processes, while occasional microtubules were intermingled with shorter and looser bundles of filaments. Thus, neoplastic fibrillary astrocytes in ENU‐induced gliomas simulate the various stages in the differentiation of normal fibrillary astrocytes. This suggests that the ratio of microtubules to filaments may be one of the more discriminating criteria by which the degree of differentiation of neoplastic astrocytes can be established.
A LIGHT AND ELECTRON MICROSCOPIC STUDY OF AXON REACTION IN THE RED NUCLEUS OF THE RAT FOLLOWING CERVICAL AND THORACIC LESIONS
Authors: EGAN D. A. , FLUMERFELT B.A. , GWYN D. G.
Published: May 2008

Egan D.A., Flumerfelt B.A. & Gwyn D.G. (1977) Neuropathology and Applied Neurobiology 3, 423–439

A light and electron microscopic study of axon reaction in the red nucleus of the rat following cervical and thoracic lesions

Axon reaction in neurons of the caudal 200 pm of the red nucleus was studied by light and electron microscopy from 1–250 days after axotomy at cervical and at thoracic levels. Following cervical lesions, severe chromatolysis occurred on the third day and by 55 days all of the neurons were atrophic. After thoracic lesions, the reaction was less intense and by 55 days the neurons had returned to normal. The initial morphological changes suggested a regenerative response which was characterized by early dissolution of the ER followed by an increase in its elaboration from the nuclear envelope, and the formation of a nuclear cap. Dilated cisternae of ER were observed in both groups and were seen to contain material similar to that in the ER cisternae generally. Neurofilamentous hyperplasia was most prominent at day 7 in both groups. Neurons of those operated at the cervical level became atrophic at the later stages and signs of autophagy were seen. Evidence of neuronal degeneration, characterized by densely packed whorls, vacuoles and dense bodies, was also seen. The fate of the neuron, i.e. regeneration, atrophy or death, appeared to be determined by the percentage of cytoplasm lost.
OBSERVATIONS ON REMYELINATION IN THE RABBIT SPINAL CORD FOLLOWING DEMYELINATION INDUCED BY LYSOLECITHIN
Authors: BLAKEMORE W. F.
Published: May 2008

The extent and type of remyelination that occurred following demyelination induced by intraspinal injection of small volumes of lysolecithin was examined in 24 rabbits. Unlike the rat and cat following this procedure remyelination is not complete even after 6 months' survival and little Schwann cell invasion occurs. The cellular environment around remyelinated and persistently demyelinated axons differed. Remyelination was associated with a good astrocytic presence and removal of myelin debris, while persistently demyelinated axons were surrounded by myelin debris and a poor astrocytic presence. It was concluded that the environment around the demyelinated axon influences oligodendrocyte remyelination.
ARREST OF MYELINATION AND DEMYELINATION IN RABBIT RETINA INDUCED BY HERPES SIMPLEX VIRUS INFECTION
Authors: KRISTENSSON K. , WIśNIEWSKI H. M.
Published: May 2008

Herpes simplex virus was injected into the vitreous of suckling and adult rabbits. In the suckling rabbits the infection caused an arrested myelination of the strip. Further, the infected strips showed degenerative changes with splitting and distension of myelin sheaths which then disintegrated. Ultrastructurally, herpes simplex virus particles were found in both oligodendroglial cells and in astrocytes in the bundles. No increase in intraocular pressure was recorded during the inflammation. The infection spread along optic pathways to the opposite side. Inflammatory cells appeared at the surface and infiltrated the degenerating strip. Especially in the contralateral eye, an extensive inflammatory cell infiltration was seen among bundles of nerve fibres which showed partly well‐preserved myelin and partly with signs of demyelination reminiscent of the picture of experimental allergic encephalomyelitis in the epiretinal strip.
GLIAL FIBRILLARY ACIDIC PROTEIN IN HUMAN GLIOMAS
Authors: MEULEN J. D. M. VAN DER , HOUTHOFF H. J. , EBELS E. J.
Published: May 2008

The presence of GFA protein, an astrocyte specific antigen, was investigated in surgical biopsies of ninety‐five gliomas using an immunoperoxidase detection method. In some cases electron microscopy was added and also in one tumour immunoelectron microscopy. The results were correlated with the histological classification and grading of the tumours. In astrocytomas, the number of GFA positive cells decreased with increasing malignancy. Some malignant oligodendrogliomas surprisingly showed GFA in oligodendroglial and gemistocytic tumour cells. Thus, transition from oligodendroglial into astrocytic tumour cells seems to occur. In the mixed astrocytoma/oligodendrogliomas, theoli godendroglioma areas were negative. Subependymomas were strongly GFA positive, whereas ependymomas and medulloblastomas were negative. The presence or absence of GFA seems to contribute a ‘hard’ criterion for classifying gliomas and may be helpful in grading them according to the degree of malignancy.
A QUANTITATIVE HISTOLOGICAL STUDY OF CHANGES IN NEURONS AND GLIA IN THE GUNN RAT BRAIN
Authors: STURROCK R. R. , JEW JEAN Y.
Published: May 2008

The rostral part of the anterior limb of the anterior commissure (RAL) and the indusium griseum of the brains of Gunn rats and Wistar rats were examined quantitatively to assess the effects of hyperbilirubinaemia on the developing nervous system. The number of glia in the RAL was significantly less in Gunn rats than in the Wistar rats. The number of glia in the indusium griseum was similar in both groups but the Gunn rats showed a decrease of about 20% in the number of neurons in this region. Myelination appeared to be unaffected and apart from an apparent increase in the number of dense bodies in astrocytes and oligoden‐drocytes there were no obvious morphological changes in either glia or neurons.
AN IMMUNOFLUORESCENCE STUDY OF THE PASSIVE ARTHUS REACTION IN RAT SCIATIC NERVE
Authors: RIDLEY A. , RAINBIRD SUSAN
Published: May 2008

The Arthus reaction, passively induced in rat sciatic nerve by local injection of antibody and intravenous injection of antigen, was studied by immunofluore‐scence, using fluorescein and tetramethylrhodamine isothiocyanate. The reaction in nerve is similar to that occurring in skin. Antigen‐antibody complexes formed at the site of the reaction activate complement and attract large numbers of poly‐morphonuclear leucocytes which then ingest the immune complexes. The significance of the Arthus reaction in relation to diseases of the peripheral nervous system is mentioned.
PATHOGENESIS OF LONGITUDINAL SPLITTING OF MUSCLE FIBRES IN NEUROGENIC DISORDERS AND IN POLYMYOSITIS
Authors: SWASH M. , SCHWARTZ M. S. , SARGEANT MARGARET K.
Published: May 2008

Longitudinal splitting of muscle fibres has been studied in the biopsies of eighteen patients with neurogenic disorders, and of twenty with polymyositis. In neurogenic disorders splitting predominantly affects hypertrophied fibres, and is probably due to mechanical overload induced by normal loads imposed on a weakened muscle. A similar phenomenon occurs in hypertrophied fibres in chronic polymyositis. However, in acute, or active polymyositis an appearance resembling fibre splitting can result from sequestration of necrotic segments within a fibre and also from regeneration occurring within intact sarcolemmal tubes after segmental sub‐endomysial necrosis. These different processes, which can be distinguished by light and ultrastructural criteria, are important compensatory factors in neuromuscular disorders.
THE EFFECT OF 5‐BROMODEOXYURIDINE ON REMYELINATION IN THE PERIPHERAL NERVOUS SYSTEM OF THE MOUSE
Authors: HALL SUSAN M. , GREGSON N. A.
Published: May 2008

The thymidine analogue, 5‐bromodcoxyuridine (BrdU), has been used in an attempt to manipulate experimentally the proliferative response of the Schwann cell population that follows induction of segmental demyelination in the peripheral nervous system. It was found that in the presence of BrdU, a significant number of Schwann cells displayed a susceptibility to the agent, in that they could be ‘held’ in the pro‐myelinated state. It is suggested that there is some regulatory transition requiring the priming of the Schwann cell genome for myelination that occurs before the remyelinating phase of repair can be started, but after the establishment of the Schwann cell/axon relationship.
THE PATHOGENESIS AND PATHWAY INTO THE CENTRAL NERVOUS SYSTEM AFTER INTRAOCULAR INFECTION OF HERPES SIMPLEX VIRUS TYPE I IN RABBITS
Authors: NARANG H. K. , CODD A. A.
Published: May 2008

Herpes simplex virus (HSV) type I was injected into the right eye of 18‐day‐old New Zealand albino rabbits and the animals were killed on the fourth and eighth days after inoculation. Longitudinal section of the optic nerves and chiasma showed that both myelinated axons and neuroglial cells crossed at the chiasma. Semi‐serial (1 μm) and ultrathin sections showed the presence of HSV in both astrocytes and oligodendrocytes, although no particles were seen in the myelinated axons; the infected cells were confined to the medial side of the right optic nerve. HSV travels centropetally along the optic pathway and slowly spreads laterally by cell‐to‐cell infection. The virus does not appear to kill the astrocytes and oligodendrocytes, and also does not directly damage the myelin sheath.
A DEVELOPMENTAL STUDY OF EPIPLEXUS CELLS AND SUPRAEPENDYMAL CELLS AND THEIR POSSIBLE RELATIONSHIP TO MICROGLIA
Authors: STURROCK R. R.
Published: May 2008

Intraventricular macrophages are first seen attached to the presumptive choroid plexus in the 11 days postconception mouse. By 12 days postconception supraependy‐ ma1 macrophages are present as well as a few macrophages lying apparently free within the ventricles. The number of epiplexus, supraependymal and free macro‐ phages increases rapidly and reaches a peak at 17 days postconception, then fall rapidly until 4 days post natum. A second increase in epiplexus and supraependymal cells occurs at 8 days post natum followed by another decrease up to 15 days post natum. Microglia were first observed in the brain at 13 days postconception and at 17 days postconception a microglial cell was observed apparently entering the ependyma from the ventricle. It is suggested that the large decrease in intraventricular macrophages after 17 days postconception is due to many of these cells migrating into the brain to give rise to microglia. The intraventricular macrophages them‐ selves probably arise from within the choroid plexus, either from stromal cells or from blood‐borne macrophages.
PARTIAL DEMYELINATION OF CAT SPINAL CORD AFTER X‐IRRADIATION AND SURGICAL INTERFERENCE
Authors: BLAKEMORE W. F.
Published: May 2008

Following 4000 rad of X‐irradiation and transplantation of sciatic nerve over the dorsal columns, extensive partial demyelination occurred in some animals. This dose of radiation inhibits remyelination so this phenomenon could be studied knowing that remylination was absent. Partial demyelination was characterized by translocation of myclin to form large myelin ovoids which remained associated with the remaining thinned myelin sheath: nodal widening, involvement of one paranode only, transition from thin to thick myelin along an internode, enlargement and disorientated oligodendrocyte tongues were also features of this change. It is concluded that partial demyelination results when oligodendrocytes have to function in a sub‐optimal environment.
PROTEIN AND NUCLEIC ACID CONTENT IN THE AGING HUMAN BRAIN*
Authors: NABER D. , DAHNKE H. G.
Published: May 2008

Naber D. & Dahnke H.G. (1979) Neuropathology and Applied Neurobiology5, 17–24

Protein and nucleic acid content in the aging human brain

The frontal cortex, white matter, cerebellum, caudate nucleus, thalamus and putamen of human brains, ranging from 16 to 91 years, were assayed for protein and nucleic acids. In all these areas the protein content decreased by 5–15% between 30 years and 90 years‐of‐age. The nucleic acid content, however, did not show any significant change. During a post‐mortem interval of 6–25 hours there was no significant decrease found in either the protein or the nucleic acid content of brain tissue.
PERIPHERAL NERVOUS SYSTEM IN A CASE OF CANINE GIANT AXONAL NEUROPATHY
Authors: DUNCAN I. D. , GRIFFITHS I. R.
Published: May 2008

Duncan I.D. & Griffiths I.R. (1979) Neuropathology and Applied Neurobiology5, 25–39

Peripheral nervous system in a case of canine giant axonal neuropathy

The pathology of the peripheral nerves in a dog with naturally occurring giant axonal neuropathy (GAN) is described. Axonal swellings were found predominantly in the distal portions of the tibial and recurrent laryngeal nerves. Excess neuro‐filaments, often arranged in whorls, were present in the swellings which were found in both myelinated and non‐myelinated fibres. Other axonal organelles tended to be isolated in small pockets and on occasions adaxonal Schwann cell processes partially separated these organelles from the axoplasm. The myelin sheath was attenuated over the swellings and short lengths of demyelinated axon were often seen adjacent to the enlargements. Some Schwann cells also contained excessive microfilaments. The peripheral nerve pathology in the dog appears closely similar to that of human GAN and to certain experimental toxic neuropathies, particularly those produced by n‐hexane and methyl‐butyl ketone.
ULTRASTRUCTURAL CHANGES OF OLIGODENDROGLIA AND MYELIN SHEATHS INDUCED BY ETHIDIUM BROMIDE
Authors: YAJIMA KUNIO , SUZUKI KINUKO
Published: May 2008

Yajima K. & Suzuki K. (1979) Neurobiology and Applied Neuropathology5, 49–62

Ultrastructural changes of oligodendroglia and myelin sheaths induced by ethidium bromide

Intracisternal injection of ethidium bromide, an inhibitor of mitochondria associated RNA, DNA and protein synthesis, produced status spongiosus in the subpial surface of the CNS of rats. Ultrastructurally, numerous intra‐myelink vacuoles and prominent degenerative changes of oligodendroglia were observed. The vacuoles were formed between the myelin lamellae by splitting of the intraperiod lines, between the axolemma and the innermost myelin lamellae, and/or between the inner tongue of oligodendroglia and myelin lamellae. In the degenerating oligodendroglia, proliferation and alteration of the endoplasmic reticulum were prominent. In places, altered membranes of the endoplasmic reticulum formed concentrical scroll‐like structures. These ultrastructural changes in ethidium bromide treated rats were compared with other similar previously described changes in animals treated with TET, cuprizone, hexachlorophene, hypocholesterolaemic drugs and actino‐mycin D.
A QUANTITATIVE STUDY OF THE GLIA OF THE PURKINJE CELL LAYER OF THE CEREBELLUM IN MAMMALS
Authors: MANN D. M. A. , YATES P. O.
Published: May 2008

Mann D.M.A. & Yates P.O. (1979) Neuropathology and Applied Neurobiology5, 71–76

A quantitative study of the glia of the Purkinje cell layer of the cerebellum in mammals

The cerebella of fourteen mammals have been examined and the number of each DNA class of glial cell, within the Purkinje cell layer, counted. Diploid glial cells were present in all species and related in number to the surface area of the Purkinje cell. It is likely that they assist in the maintenance of the physiology of this latter cell type. Tetraploid glial cells, however, occur in significant numbers only in the human and chimpanzee and possibly play a part in the establishment of certain learned patterns of co‐ordinated movement peculiar to these species.
SPINAL CORD TRANSECTION: A QUANTITATIVE ANALYSIS OF ELEMENTS OF THE CONNECTIVE TISSUE MATRIX FORMED WITHIN THE SITE OF LESION FOLLOWING ADMINISTRATION OF PIROMEN, CYTOXAN OR TRYPSIN
Authors: MATTHEWS M. A. , ONGE M. F. ST. , FACIANE C. L. , GELDERD J. B.
Published: May 2008

Spinal cord transection: a quantitative analysis of elements of the connective tissue matrix formed within the site of lesion following administration of piromen, cytoxan or trypsin

Long‐Evans hooded rats were cordotomized at the T‐5 level and given either (1) cyclophosphamide (cytoxan), an immunosuppressive, (2) piromen, a bacterial polysaccharide‐nucleic acid complex, (3) topical and systemic trypsin, or (4) no further specific treatment. Because of past and present controversy surrounding the proposed ability of these agents to promote spinal cord regeneration, a systematic study, employing light and electron microscopy, and quantitative methods in a single animal model, was done in order to re‐evaluate the effects of each treatment upon the connective tissue matrix which forms in the defect left by transection. After an initial inflammatory reaction during the first week after surgery, the lesion zone is characterized either by areas of dense collagenous connective tissue with occasional fibroblasts and macrophages, or a loose areolar tissue with numerous sheets and cords of mesodermal cellular elements but minimal collagen. By 45 days postoperatively (dpo), axons supported by Schwann cells invade and become entangled in the loose connective tissue matrix. With longer postoperative survival, cysts appear craniad and caudad to the lesion and erode much of the scar together with viable neural tissue. Giving cytoxan or piromen did not result in any qualitative alteration of the scar matrix as evidenced by electron microscopy. Quantitative analysis revealed a slight reduction in the fibrous connective tissue component of the scar at 45–90 dpo, but this was transient when longer postoperative periods were studied. Trypsin caused a significant reduction in the amount of fibrous connective tissue with a concomitant increase in loose connective tissue and the appearance of a few distinctive, compact bundles of unmyelinated axons lacking Schwann cells.
THE CELLULAR ORIGIN OF LYSOSOMAL ENZYMES IN THE PLAQUE IN MULTIPLE SCLEROSIS.
Authors: ALLEN INGRID V. , GLOVER G. , McKEOWN STEPHANIE R. , McCORMICK D.
Published: May 2008

The cellular origin of lysosomal enzymes in the plaque in multiple sclerosis. II. A histochemical study with combined demonstration of myelin and acid phosphatase.

Existing techniques have been adapted and it has been possible to demonstrate acid phosphatase (APP) and myelin, lipid or astrocytic fibres in the same histological section. In normal controls APP was demonstrated in neurons, astrocytes, ependy‐ma including choroid plexus epithelium and in pericytes, but not in oligodendro‐cytes. In multiple sclerosis (MS), APP positive cells were found in the plaque, plaque edge and macroscopically normal white matter. Contrary to some previous reports, not only macrophages, but also astrocytes in the MS plaque were found to be APP positive, although the distribution of enzyme in these cells was predominantly diffuse, unlike the particulate distribution in normal astrocytes and other APP positive cells: the significance of this finding is discussed. It is concluded that astrocytes and macrophages are the main source of the elevated levels of APP found biochemically in MS and that in old plaques astrocytes make the major contribution.
TELLURIUM‐INDUCED NEUROPATHY: CORRELATIVE PHYSIOLOGICAL, MORPHOLOGICAL AND ELECTRON MICROPROBE STUDIES
Authors: DUCKETT S. , SAID G. , STRELETZ L. G. , WHITE R. G. , GALLE P.
Published: May 2008

Tellurium‐induced neuropathy: correlative physiological, morphological and electron microprobe studies

Elemental tellurium (Te) was included in the normal diet of 15–day‐old rats and every day thereafter for 35 days. Within 24 hours a segmental demyelination was seen in the sciatic nerve. On the 2nd day, Te was localized in the cytoplasm of the Schwann cells. On the 3rd day paralysis of the hind legs appeared which lasted 7–10 days. The paralysis then disappeared and demyelination ceased, although the rats were still ingesting Te. After one week there was also slight demyelination in the brachial plexus. Motor nerve conduction velocities were reduced below the normal control range, but only after the rats had taken Te for at least 7 days. This peripheral neuropathy can only be induced in the rat by Te ingestion between the 15th and 35th days of post‐natal life, not before or after this period of time.
THE FINE STRUCTURE OF THE CNS IN MULTIPLE SCLEROSIS.
Authors: KIRK J.
Published: May 2008

The fine structure of the CNS in multiple sclerosis. II. Vesicular demyelina‐tion in an acute case

Tubular vesicular and net‐like dissolution of myelin sheaths associated with complete demyelination and preservation of axons, is described in the brain, obtained within 4 h of death, from a patient who died with acute multiple sclerosis (MS). It was rare, being found in only three out of twenty‐three blocks examined, and was seen mainly in the partially demyelinated margin of an active plaque in the white matter. The possibility that post‐mortem autolytic changes or fixation artefact might have accounted for the appearances is considered, but is thought unlikely. The findings, though not specific would be expected if current theories invoking myelin‐directed ‘autoimmune’ mechanisms in MS pathogenesis are correct. However, other myelin‐directed mechanisms cannot be excluded on the basis of this evidence alone.
LATE RADIATION DAMAGE TO THE CENTRAL NERVOUS SYSTEM: A RADIOBIOLOGICAL INTERPRETATION
Authors: HOPEWELL J. W.
Published: May 2008

Annotation. Late radiation damage to the central nervous system: a radiobiological interpretation

The evidence in support of the two opposing views as to the pathogenesis of late radiation damage to the central nervous system after therapeutic doses of radiation are briefly reviewed. Analysis of the radiation dose levels used by various investigators holding opposing views as to Pathogenesis of CNS lesions they reported, suggests that both groups of protagonists were in part correct. Both vascular and glial changes are important in the development of late radiation damage to the nervous system; the preponderance of one or the other type of cell damage depends upon the radiation dose. Vascular effects occur at lower dose levels but after a longer latent period than effects mediated through damage to neuroglia. Current radiobiological concepts and their possible importance in establishing the radiosensitivity of the central nervous system are discussed. The origins of both vascular and neuroglial cell mediated changes are discussed in terms of the reproductive loss of radiation damaged cells. This view is supported by some recent experimental findings. The radiobiological basis of some recently investigated treatment modalities aimed at improving the control of intracranial gliomata by radiotherapy are also considered.
MORPHOMETRIC STUDIES OF RAT GLIAL CELL ULTRASTRUCTURE AFTER UREASE‐INDUCED HYPERAMMONAEMIA
Authors: LAURSEN H. , DIEMER N. H.
Published: May 2008

Morphometric studies of rat glial cell ultrastructure after urease‐induced hyperammonaemia

The ultrastructure of astrocytes and oligodendrocytes was investigated in hyper‐ammonaemic rats injected daily with urease for 4 days. Glial cells were randomly photographed and magnified × 28 000. Cell and nuclear sizes were estimated by planimetry. and mitochondrial size and density were measured by image analysis. After 4 days of hyperammonaemia the astrocyte cytoplasmic area was increased by 46%. Mitochondrial area was increased by 20%, but after correction for cytoplasmic oedema the number and size of mitochondria were not significantly increased. The nuclear and cytoplasmic areas of oligodendrocytes were unchanged. The mitochondria of oligodendrocytes were small in the hyperammonaemic group and so was their percentage area to cytoplasmic area, but their numbers were unchanged. It, was concluded that hyperammonaemia induces astrocyte oedema and increases the astrocyte mitochondrial content. These findings support the assumption that the astrocytes are the active cells in the brain metabolism of ammonia. The decrease in oligodendrocyte mitochondrial content could be considered a point against an active function of oligodendrocyte mitochondria in ammonia metabolism in hyperammonaemia.
UPTAKE AND RETROGRADE AXONAL TRANSPORT OF HORSERADISH PEROXIDASE IN NORMAL AND AXOTOMIZED MOTOR NEURONS DURING POSTNATAL DEVELOPMENT
Authors: OLSSON T. , KRISTENSSON K.
Published: May 2008

Olsson T. & Kristensson K. (1979) Neuropathology and Applied Neurobiology5, 377–387

Abstract Uptake and retrograde axonal transport of horseradish peroxidase in normal and axotomized motor neurons during postnatal development

The axonal uptake and somatopetal transport of horseradish peroxidase (HRP) was studied during early postnatal development of facial neurons in mice and rats. HRP injected systemically or locally into the muscles of the vibrissae, diffused into the region of the immature neuromuscular junction and was incorporated into vesicles in the axon terminals on the first and third postnatal days, at a time when synaptic vesicles were already present. HRP later was found in the nerve cell bodies of the facial nucleus in the brain stem indicating a somatopetal transport of the tracer in axons. The response of facial neurons to nerve transection changed from rapid neuronal death to prolonged survival between the 6th and 10th postnatal day. HRP was transferred to nerve cell bodies after topical application to the proximal stump of transected facial nerves in rats 3 days‐of‐age. In the perikaryon it was localized to vesicles and vacuoles with no signs of leakage into the cytoplasm. In the light of our findings different hypotheses for the mechanism of the neuronal death in the immature animals are discussed.
EXPERIMENTAL OBSTRUCTIVE HYDROCEPHALUS IN THE RAT: A SCANNING ELECTRON MICROSCOPIC STUDY
Authors: COLLINS PATRICIA
Published: May 2008

Experimental obstructive hydrocephalus in the rat: a scanning electron microscopic study

Hydrocephalus was induced in 12‐day old rats by the cisternal infusion of a concentrated kaolin suspension. The animals were killed at day 20 and the ependymal lining of all the ventricles prepared for scanning electron microscopy. The dilation of the ventricles was moderate to gross in all cases. The ependyma of the lateral ventricles was similar in both control and experimental animals. Ependymal damage was present in six out of the twelve hydrocephalic rats. Two had fibres visible on the ependymal surface. Four had tears covered with small round cells, believed to be responsible for the repair of the ependyma. The third ventricle, cerebral aqueduct and fourth ventricle enlarged by incorporating folds of ependyma, present in control animals, into the ventricular walls. The circumventricular organs present in the third and fourth ventricles were not damaged by the dilation of the ventricles, even in severe hydrocephalus.
FOETAL BRAIN DEVELOPMENT IN THE SHEEP
Authors: McINTOSH G. H. , BAGHURST KATRINE I. , POTTER B. J. , HETZEL B. S.
Published: May 2008

Abstracts McIntosh G.H., Baghurst K.I., Potter B.J.& HetzelB.S. (1979) Neuropathology and Applied Neurobiology5, 103–114

Foetal brain development in the sheep

The pattern of normal foetal brain development has been described for the Merino sheep. Controlled flock matings were used and foetuses removed by hysterotomy at 40, 54, 67, 81, 90, 95, 109, 121, and 150 days of gestation. Lambs at 7 days after birth and adults were also studied. The CNS was dissected, separated and weighed as four segments—cerebral hemispheres, brain stem, cerebellum and spinal cord. Determinations of DNA, RNA, protein, cholesterol and water content were subsequently carried out on each segment. Brain weight increased from 0.264 g (40 days) to 52.74 g at 150 days. The ratio to body weight decreased from 6.7% (40 days) to 1.5% (150 days). DNA increased more rapidly from 40 to 90 days in the cerebral hemispheres and brain stem than in the cerebellum and spinal cord and this increase preceded the main increase in weight. Increases in cholesterol and decreases in water content were also more marked in the cerebral hemispheres and brain stem. Increase in brain weight occurred in two phases, one up to 90 days followed by a more rapid and larger increase after 90 days which continued to birth. These two phases appear to reflect an increase in neuroblast multiplication followed by neuroglial multiplication and myelination respectively. At birth, brain weight had reached 50% of adult size, the cerebral hemispheres 52% of adult size, the cerebellum 40% and spinal cord 40%. The relative maturity of the brain at birth justifies the classification of the sheep as a prenatal brain developer.
THE EFFECTS OF POSTNATAL LEAD EXPOSURE ON Purkinje cell DENDRITIC DEVELOPMENT IN THE RAT
Authors: McCONNELL P. , BERRY M.
Published: May 2008

Abstracts McConnell P. & Berry M. (1979) Neuropathology and Applied Neurobiology5, 115–132

The effects of postnatal lead exposure on Purkinje cell dendritic development in the rat

Rat pups, suckled by mothers maintained after parturition on a diet containing 4% lead acetate, were killed at 30 days and their cerebella examined. The blood lead was greatly increased in these animals (258.20 26.72 μg/100 ml) as compared with controls (4.75 ± 0.75 pμ/100 ml) and their mean body weight was reduced by 28%. Cerebellar weight, however, remained unchanged. Histologically the vermis showed vacuolation of the white matter and an increase in the size of Purkinje cell bodies. The total number of Purkinje and granule cells and their densities were unchanged except in animals with encephalopathy when these parameters were reduced. Network analysis of the dendritic trees of Purkinje cells indicated a 34.8% reduction in total dendritic length, due to reduction in total segment number and in the length of distal segments. Dendritic density and the frequency of trichotomous branching were unchanged by the experimental treatment. The density of dendritic spines over the periphery of the network was normal. The topology of the dendritic trees of Purkinje cells was abnormal in that branching patterns deviated from the normal pattern generated by random terminal growth. These results suggest that lead causes changes in Purkinje cell metabolism which reduce the rate of dendritic growth and cause abnormal branching. It remains to be determined whether these are direct effects or secondary to the vascular changes known to occur in the cerebellum during lead intoxication.
VASOACTIVE INTESTINAL POLYPEPTIDE IN THE PITUITARY PARS NERVOSA
Authors: NOORDEN SUSAN VAN , POLAK JULIA M. , BLOOM S. R. , BRYANT M. G.
Published: May 2008

Abstracts Van Noorden S., Polak J.M., Bloom S.R. & Bryant M.G. (1979) Neuropathology and Applied Neurobiology 5, 149–153

Vasoactive intestinal polypeptide in the pituitary pars nervosa

Vasoactive intestinal polypeptide (VIP) is a widely distributed neuropeptide which has recently been found in the hypothalamus and in hypothalamo‐hypophyseal portal blood. We have examined the pituitary of several mammalian species for the presence of VIP by immunocytochemistry and radioimmunoassay and report here that the pars nervosa contains a considerable quantity of VIP (100–250 fmol/ mg) which, in the dog, can be shown to be present in nerve fibres. It is possible that neurohypophyseal VIP may be a local releasing agent for vasopressin.
MULTIPLE SCLEROSIS: A QUANTITATIVE AND QUALITATIVE STUDY OF IMMUNOGLOBULIN‐CONTAINING CELLS IN THE CENTRAL NERVOUS SYSTEM
Authors: ESIRI MARGARET M.
Published: May 2008

Multiple sclerosis: a quantitive and qualitative study of immunoglobu‐lin‐containing cells in the central nervous system

Autopsy material from the brains and spinal cords of twenty‐three patients with multiple sclerosis was examined with the immunoperoxidase (PAP) method to compare the distribution of immunoglobulin (Ig)‐containing cells in demyelinated plaques and normally myelinated tissue. Ig‐containing cells were much more numerous within plaques than outside them and were more common in recent than in old plaques. Most of the heavy chain present was IgG with small amounts also of IgA. More cells were demonstrated to contain light chains than heavy chains. It is suggested on the basis of the pattern of distribution of Ig‐containing cells that a stimulus to B‐cell proliferation and maturation resides within plaques.
FURTHER OBSERVATIONS ON PARTICULATE STRUCTURES IN SCRAPIE AFFECTED BRAIN
Authors: NARANG H. K. , CHANDLER R. L. , ANGER H. S.
Published: May 2008

Further observations on particulate structures in scrapie affected brain

A search procedure at the ultrastructural level revealed characteristic particulate structures in mice of two further laboratory stocks experimentally inoculated with scrapie. The structures represent a specific change related to scrapie disease; their relationship to the scrapie agent is discussed.
THE ASSOCIATION OF HYDROCEPHALUS AND ARNOLD‐CHIARI MALFORMATION WITH SPINA BIFIDA IN THE FETUS
Authors: BELL JEANNE E. , GORDON A. , MALONEY A. F. J.
Published: May 2008

The association of hydrocephalus and Arnold‐Chiari malformation with spina bifida in the fetus.

Twenty‐one fetuses with spina bifida and twenty apparently normal fetuses of between 14–23 weeks gestation were examined for the presence of hydrocephalus and Arnold‐Chiari malformation. Sacral, lumbo‐sacral, lumbar, thoraco‐lumbo‐sacral and thoraco‐lumbar lesions were found. Some were closed, some were open. The amount of neural tissue at the site of the lesion was very variable. In three cases, diastematomyelia was found. The heads of spina bifida fetuses were not enlarged. Hydrocephalus was found in eleven of them and the Arnold‐Chiari malformation in twelve. In nine fetuses the abnormalities co‐existed. Hydrocephalic brains showed depression of the tentorium, abnormalities in the corpus callosum and absence of the lateral fissure. The more cephalad and extensive the spinal lesion, the more likely it was to be accompanied by brain abnormalities. Isolated sacral defects were not associated either with hydrocephalus or with the Arnold‐Chiari malformation. Pathological changes in the brain occurred in the presence of both open and closed spinal lesions and were apparently unrelated to fetal age. No evidence was found as to the sequence in which these brain abnormalities appeared.
A COMPARATIVE QUANTITATIVE AND MORPHOLOGICAL STUDY OF AGEING IN THE MOUSE NEOSTRIATUM, INDUSIUM GRISEUM AND ANTERIOR COMMISSURE
Authors: STURROCK R. R.
Published: May 2008

A comparative quantitive and morphological study of ageing in the mouse neostriatum, indusium griseum and anterior commissure R. R. Sturrock

The glia: neuron ratio increased between 5 and 9 months in the neostriatum and indusium griseum and thereafter remained constant until 18 months‐of‐age. Between 18 and 22 months the glia:neuron ratio did not change in the neostriatum, but increased significantly in the indusium griseum due to a combination of a loss of neurons and an increase in glia. The 6–9 month rise was mainly due to an increase in the number of astrocytes in both regions although there was some increase in oligodendrocytes at this time. The increase in glia in the indusium griseum between 18 and 22 months was due to an increase in both astrocytes and microglia. In the anterior commissure, the pattern of glial change was almost identical in both limbs with oligodendrocytes increasing between 6 and 9 months then decreasing between 9 and 18 months. Astrocytes decreased between 6 and 18 months. Between 18 and 22 months oligodendrocytes and microglia both increased in number. There was a decrease in glioblasts in both limbs with age. The age at which lipofuscin appeared was different in each type of glial cell and in each region studied. Microglia contained lipofuscin at 6 months in all regions. Astrocytes first contained lipofuscin at 6 months in the neostriatum, at 9 months in the indusium griseum and at 15 months in the anterior commissure. Oligodendrocytes first contained lipofuscin at 12 months in the anterior commissure, at 18 months in the indusium griseum and at 18 months in the neostriatum. Ependy‐mal cells adjacent to the neostriatum contained lipofuscin and osmiophilic lipid at 6 months but by 12 months the latter had become much less osmiophilic. Foamy pericytes were found in all regions: from 6 months in the neostriatum; from 9 months in the indusium griseum and from 15 months in the anterior commissure. These contained lipid droplets, were only found adjacent to arterioles or venules, and were likely Ibrahim's neurolipomastocytes. The response of glia to ageing varies in different regions of grey matter, but is similar in two different regions of white matter. These age changes may be related to different levels of metabolic activity of glia in different parts of the brain.
ANAPLASTIC EPENDYMOMA OF THE SPINAL CORD
Authors: MØRK S. J. , RISBERG G. , KROGNESS K.
Published: May 2008

Mork S.J., Risberg G. & Krogness K. (1980) Neuropathology and Applied Neurobiology 6, 307–311

Anaplastic ependymoma of the spinal cord

An intraspinal ependymoma with cytological signs of malignancy and unusual further development was diagnosed in a 12‐year‐old boy. Only partial removal was possible and postoperative Co60 treatment was given. Ascending tumour growth was evident clinically in the spinal canal, and 3 months later signs of intracranial extension of the tumour developed. The patient died 6½ years after the onset. Autopsy showed an anaplastic ependymoma with extensive intraspinal and intracranial growth. No other neoplasms were found. There was extraspinal extension of tumour into the laminectomy scar, but no metastases.
ULTRASTRUCTURAL CHANGES OF MUSCLES DURING ATTACKS OF ADYNAMIA EPISODICA HEREDITARIA
Authors: WALTER G. F. , AUBOCK L.
Published: May 2008

Walter G.F. & Auböck L. (1980) Neuropathology and Applied Neurobiology 6, 313–317

Case report. Ultrastructural changes of muscles during attacks of adynamia episodica hereditaria

In an ultrastuctural study of biopsies of quadriceps femoris muscle from two patients during attacks of adynamia episodica hereditaria. Marked pinocy‐tosis along the sarcolemma and an interfibrillary oedema were observed, together with a ‘bamboo‐like’ shape of the myofibrils. Other non‐specific abnormalities were also found.
ANNOTATION: RECENT BIOCHEMICAL AND IMMUNOLOGICAL OBSERVATIONS IN MULTIPLE SCLEROSIS
Authors: CUZNER M. L.
Published: May 2008

Cuzner M.L. (1980) Neuropathology and Applied Neurobiology 6, 405–414

Annotation. Recent biochemical and immunological observations in multiple sclerosis

As there is evidence of early biochemical and histological changes in the normal‐appearing white matter in MS, which appear to be independent of or precede demyelination, the formation of plaques may be incidental to a more primary lesion. The finding of persistently increased levels of IgG in the CSF of patients with MS points to an ongoing immune reaction in the CNS, possibly against an infective agent; but virus‐specific antibodies account for only a small proportion of the IgG in the CSF. Furthermore, in vitro assays of T cell function suggest that there may be a regulator T cell defect in MS. Salk and colleagues (1980) have postulated that MS may be a disorder, attributable to multiple inducing agents, which is potentiated through deregulation of lymphocyte function.
THE EFFECT OF SUB‐DURAL NERVE TISSUE TRANSPLANTATION ON THE SPINAL CORD OF THE RAT
Authors: BLAKEMORE W. F.
Published: May 2008

Blakemore W.F. (1980) Neuropathology and Applied Neurobiology 6, 433–447

The effect of sub‐dural nerve transplantation on the spinal cord of the rat

The effects of sub‐dural transplantation of autologous sciatic nerve on the dorsal columns of the rat was investigated. Combinations of the following procedures were used: 1 local X‐irradiation with 4000 rad to suppress inherent remyelination activity; 2 small areas of primary demyelination induced by injection of lysolecithin or 6‐aminonicotinamide; 3 transplantation of untreated or freeze‐killed nerve, either teased or unteased. The lesions formed were examined for suppression of remyelination by local cells, remyelination by transplanted Schwann cells, deleterious effects of transplantation on the spinal cord, and the presence of suprapial nerve fibres. The following conclusions were drawn: 1 that 4000 rad of local X‐irradiation suppresses inherent remyelination by oligodendroglia and local Schwann cells even when transplanted freeze‐killed sciatic nerve is present; 2 that demyelinated axons can be remyelinated by Schwann cells from transplanted untreated nerve; 3 that the placing of peripheral nerve over the dorsal columns induces primary demyelination in both irradiated and non‐irradiated animals; 4 that the placing of peripheral nerve over demyelinated locally X‐irradiated spinal cord can lead to fibrous tissue invasion of the spinal cord and partial demyelination of the lateral and ventral columns; and 5 that transplantation of viable peripheral nerve onto the dorsal columns induces the formation of suprapial nerve fibres, which increase in number if demyelination or axonal damage is present in the dorsal columns. It seems probable, therefore, that elements in the peripheral nerve may exert trophic effects on dorsal column nerve fibres.