Shigeo Murayama

Cerebellar degeneration in the Niemann-Pick type C mouse

SummaryChronological morphological changes and topographical distribution of degenerating Purkinje cells were studied in the murine model of Niemann-Pick disease type C (NPC mouse). Loss of Purkinje cells can be detected in the anterior vermis as early as 60 days of age, coinciding with early neurological signs, and progressed to total absence in the entire hemisphere and vermis with exception of nodules. Ultrastructurally, concentric lamellar inclusions were detected in the perikarya of degenerating Purkinje cells as well as in the focally enlarged branching points of their dendrites. Calbindin immunocytochemistry demonstrated dendritic pathology characterized by irregular contour of dendritic trees and decreased number of dendritic spines. Ubiquitin immunoreactivity revealed granular reaction products in the perikarya, dendrites and axons of Purkinje cells. Our studies demonstrated unique pathological features of Purkinje cells that involve perikarya, dendrites and axons in the NPC mouse.

Immunocytochemical and ultrastructural studies of Werdnig-Hoffmann disease

SummaryNeuronal alterations in two cases of Werdnig-Hoffmann disease (WH) were investigated immunocytochemically and ultrastructurally. Ballooned neurons (BNs) were found in anterior horn, Clarkes column, dorsal root ganglion and thalamus. Anti-phosphorylated neurofilament antibodies preferentially stained the peripheral perikarya and proximal neuronal processes of BNs, whereas anti-ubiquitin antibodies preferentially stained the central perikarya of BNs. Ultrastructurally, BNs showed degenerative changes ranging from a diffuse increase of neurofilaments to a centrally accentuated accumulation of mitochondria and vesicular or membranous profiles. Our studies suggest that ubiquitinated degradation products accumulate in the center of the BNs perikaryon and displace aberrantly phosphorylated neurofilaments to the periphery. BNs in WH probably reflect an intrinsic alteration in the metabolism of neurofilaments that is associated with regressive changes in the neuron and eventually neuronal death.

A unique pattern of astrocytosis in the primary motor area in amyotrophic lateral sclerosis

SummaryWe examined the primary motor area (PMA, Brodmann area 4) from 23 cases of adult-onset sporadic amyotrophic lateral sclerosis (ALS) with immunocytochemistry using anti-glial fibrillary acidic protein antibody. There was astrocytosis in the middle of the pyramidal cell layer in all cases except for one that did not present any upper motor neuron signs clinically. The astrocytosis was characterized by multiple clusters of astrocytes, some of which showed a close association with macrophages. In about a half of the cases, these multiple clusters of astrocytes became confluent and presented as a laminar astrocytosis in the middle of the pyramidal cell layer. Our studies demonstrate a unique pattern of astrocytosis in the PMA in ALS. This pattern of astrocytosis may be useful not only for diagnostic purposes, but also for a better understanding of the pathological process involving the PMA in ALS.

Immunocytochemical and ultrastructural studies of upper motor neurons in amyotrophic lateral sclerosis

SummaryThe pathological alterations in upper motor neurons were investigated in 27 cases of adult-onset sporadic amyotrophic lateral sclerosis (ALS). No signficant cytoskeletal alterations were found in the Betz cells of any of the cases except one, although cytoskeletal pathology was consistently present in lower motor neurons. The one case had severe circumscribed atrophy of the precentral gyrus and, microscopically, had argentophilic intracytoplasmic inclusions in Betz cells and other pyramidal neurons in the primary motor area as eell as in the lower motor neurons. Immunocytochemically these inclusions contained the epitope of phosphorylated neurofilament and ubiquitin and ultrastructurally consisted of granule-associated filaments with neurofilaments. This is the first demonstration of alterations of cytoskeleton and ubiquitination in the giant cells of Betz, an established subset of upper motor neurons in ALS. Thus, although uncommon, cytoskeletal changes can be found in upper motor neurons in some ALS cases.

Immunocytochemical and ultrastructural studies of eosinophilic granular bodies in astrocytic tumors

SummaryEosinophilic granular bodies (EGBs) are studied immunocytochemically and ultrastructurally in a case of low-grade and a case of high-grade astrocytoma. EGBs are recognized as brightly eosinophilic round bodies of variable size in hematoxylin and eosin-stained sections. Immunocytochemically some EGBs are positive for antibodies raised against αB-crystallin, ubiquitin and glial fibrillary acidic protein with the staining patterns for each being different from one another. Ultrastructurally EGBs consist of membrane-bound round body of various diameter ranging from 50 nm to 20 μm. Small EGBs contain electron-dense homogeneous material with occasional myelin figures, while large EGBs contain small EGB-like structures within electron-dense homogeneous material or loose granular profiles. Our studies demonstrate (1) ultrastructural variety of EGB; (2) and αB-crystallin epitope in EGB; and (3) the presence of EGB in high-grade as well as low-grade astrocytoma.

Peripheral nerve pathology in Niemann-Pick type C mouse

The sciatic nerve of the mouse mutant with Niemann-Pick type C disease (NPC mouse) was investigated using light and electron microscopy, and teased-fiber preparations. As early as postnatal day 20, when clinical symptoms were not yet apparent, focal paranodal swellings with an accumulation of small myelin figures in the Schwann cell cytoplasm were noted. These paranodal changes were more pronounced in the distal segment and became progressively conspicuous with increasing age. The morphometric analysis revealed a hypomyelination of large myelinated fibers in the NPC nerves at 70 days, whereas an essentially similar histogram pattern was noted in both control and NPC nerves at 20 days, suggesting progressively defective utilization of cholesterol in the NPC nerves with age. Intraxonal accumulation of dense bodies was noted in older mice, but no segmental demyelination or Wallerian type of axonal degeneration was observed at any age. The changes noted in the paranodal regions in the NPC mouse closely resemble those found in rats treated with an inhibitor of cholesterol biosynthesis, as well as those seen in remodeling fibers during an early stage of peripheral nerve development. Thus, the morphological changes seen in the sciatic nerve of the NPC mouse may be an expression of perturbation in myelin maintenance as a result of defective cholesterol metabolism.

Developmental Expression of Vasopressin in the Human Hypothalamus: Double-Labeling with In Situ Hybridization and Immunocytochemistry

ABSTRACT: The developmental expression of arginine vasopressin (VP) and VP mRNA in human hypothalamus was studied using combined immunocytochemistry (ICC) for VP-neurophysin II and in situ hybridization (ISH) for VP mRNA. Routine formalin-fixed autopsy material was used from 22 cases ranging in age from 18 wk of gestation to 21 yr. VP-neurophysin II immunoreactive cells were detected in the supraoptic, accessory supraoptic, and paraventricular nuclei of all brains examined. The average size of the immunocytochemically labeled cells increased until birth and remained constant thereafter. VP mRNA was first detected in cells at 21 wk gestation; 3 wk after the first detectable VP by ICC. After 27 wk of gestation, consistent and strong signals were obtained from the specimens that were double-labeled for both immunoreactive VP-neurophysin II and VP mRNA. Three populations of double-labeled cells were identified: type 1, intensely positive for both ISH and ICC (most magnocellular neurons); type 2, positive for ISH and weak or negative for ICC (rare and generally found in younger fetuses), and type 3, positive for ICC and weak or negative for ISH (mostly scattered in accessory nuclei). Thus, double-labeling techniques can be routinely used on frozen or paraffin sections of human autopsy material for the simultaneous assessment of both message and peptide. In the human fetus, the relatively late appearance of adult-like levels of VP mRNA in the magnocellular neuroendocrine cells suggests an association with the development of functional synaptic interactions in this system.

Pathological study of corticospinal-tract degeneration in Friedreich's ataxia.

The pattern of fibre degeneration in the lateral corticospinal tract (LCST) was studied in a case of Friedreichs ataxia (FA). There was preferential involvement of the lateral area of the LCST in the cervical spinal cord. More caudally, the degeneration involved the entire area of the LCST and did not reveal a medial to lateral gradient of involvement. We suggest that this distinctive pattern of tract degeneration is a consequence of the somatotopic organization of the LCST, with the dying‐back degeneration preferentially affecting those LCST fibres that extend to the lumbo‐sacral spinal cord. This pattern of tract degeneration may be a useful morphological marker of dying‐back degeneration in corticospinal tracts.

Selective sparing of betz cells in primary motor area in hypoxic-ischemic encephalopathy

SummaryTwo cases of postoperative hypoxic-ischemic encephalopathy are described in which Betz cells of the primary motor area were selectively spared. In one patient the hypoxic-ischemic encephalopathy led to a vegetative state and in the other patient to a spastic quadriparesis and cortical blindness. In contrast to the relative sparing of Betz cells, Purkinje cells of the cerebellar cortex were totally destroyed. These two cases suggest that Betz cells are relatively resistant to hypoxic-ischemic insult under certain conditions.

Onion bulb formation in the initial complex of neurons in human dorsal root ganglion: their significance and alterations in amyotrophic lateral sclerosis

SummaryWe have demonstrated onion bulb-like structures in human dorsal root ganglia (DRG). These onion bulbs morphologically consist of non-continuous layers of supporting-cell cytoplasms that encase thinly myelinated axons and are immunocytochemically recognized by anti-S-100 protein and anti-glial fibrillary acidic protein antibodies. These structures are present in normal controls and preferentially involve the initial complex of the large, light, neurofilament-rich neurons. The number of onion bulbs and their average number of lamellae reach a peak in the third decade and then decline. In three cases of amyotrophic lateral sclerosis (ALS), the onion bulbs involve non-myelinated axons as well as the thinly myelinated portion of the initial complex and are increased both in frequency and in average number of lamellae. Our studies suggest that these onion bulbs represent a normal biological process or DRG neurons that may be accentuated in ALS.