Intra-astrocytic glycogen granules and corpora amylacea stain positively for polyglucosans: a cytochemical contribution on the fine structural polymorphism of particulate polysaccharides

Astrocytes are involved in the formation of corpora amylacea-like structures from neuronal debris in the CA1 region of the rat hippocampus after ischemia

Recently, we demonstrated that the corpora amylacea (CA), a glycoprotein-rich aggregate frequently found in aged brains, accumulates in the ischemic hippocampus and that osteopontin (OPN) mediates the entire process of CA formation. Therefore, this study aimed to elucidate the mechanisms by which astrocytes and microglia participate in CA formation during the late phase (4-12 weeks) of brain ischemia. Based on various morphological analyses, including immunohistochemistry, in situ hybridization, immunoelectron microscopy, and correlative light and electron microscopy, we propose that astrocytes are the primary cells responsible for CA formation after ischemia. During the subacute phase after ischemia, astrocytes, rather than microglia, express Opn messenger ribonucleic acid and OPN protein, a surrogate marker and key component of CA. Furthermore, the specific localization of OPN in the Golgi complex suggests that it is synthesized and secreted by astrocytes. Astrocytes were in close proximity to type I OPN deposits, which accumulated in the mitochondria of degenerating neurons before fully forming the CA (type III OPN deposits). Throughout CA formation, astrocytes remained closely attached to OPN deposits, with their processes exhibiting well-developed gap junctions. Astrocytic cytoplasmic protein S100β, a calcium-binding protein, was detected within the fully formed CA. Additionally, ultrastructural analysis revealed direct contact between astroglial fibrils and the forming facets of the CA. Overall, we demonstrated that astrocytes play a central role in mediating CA formation from the initial stages of OPN deposit accumulation to the evolution of fully formed CA following transient ischemia in the hippocampus.

Thyroid Hormone Transporters MCT8 and OATP1C1 Are Expressed in Pyramidal Neurons and Interneurons in the Adult Motor Cortex of Human and Macaque Brain

Monocarboxylate transporter 8 (MCT8) and organic anion transporter polypeptide 1C1 (OATP1C1) are thyroid hormone (TH) transmembrane transporters that play an important role in the availability of TH for neural cells, allowing their proper development and function. It is important to define which cortical cellular subpopulations express those transporters to explain why MCT8 and OATP1C1 deficiency in humans leads to dramatic alterations in the motor system. By means of immunohistochemistry and double/multiple labeling immunofluorescence in adult human and monkey motor cortices, we demonstrate the presence of both transporters in long-projection pyramidal neurons and in several types of short-projection GABAergic interneurons in both species, suggesting a critical position of these transporters for modulating the efferent motor system. MCT8 is present at the neurovascular unit, but OATP1C1 is only present in some of the large vessels. Both transporters are expressed in astrocytes. OATP1C1 was unexpectedly found, only in the human motor cortex, inside the Corpora amylacea complexes, aggregates linked to substance evacuation towards the subpial system. On the basis of our findings, we propose an etiopathogenic model that emphasizes these transporters' role in controlling excitatory/inhibitory motor cortex circuits in order to understand some of the severe motor disturbances observed in TH transporter deficiency syndromes.

Osteopontin mediates the formation of corpora amylacea-like structures from degenerating neurons in the CA1 region of the rat hippocampus after ischemia

We previously demonstrated that osteopontin (OPN) is closely associated with calcium precipitation in response to ischemic brain insults. The present study was designed to elucidate the possible association between deposition of OPN and progressive neurodegeneration in the ischemic hippocampus. To address this, we analyzed the OPN deposits in the rat hippocampus after global cerebral ischemia in the chronic phase (4 to 12 weeks) after reperfusion using immunoelectron microscopy and correlative light and electron microscopy. We identified three different types of OPN deposits based on their morphological characteristics, numbered according to the order in which they evolved. Dark degenerative cells that retained cellular morphology were frequently observed in the pyramidal cell layer, and type I OPN deposits were degenerative mitochondria that accumulated among these cells. Type II deposits evolved into more complex amorphous structures with prominent OPN deposits within their periphery and within degenerative mitochondria-like structures. Finally, type III had large concentric laminated structures with irregularly shaped bodies in the center of the deposits. In all types, OPN expression was closely correlated with calcification, as confirmed by calcium fixation and Alizarin Red staining. Notably, type II and III deposits were highly reminiscent of corpora amylacea, glycoprotein-rich aggregates found in aged brains, or neurodegenerative disease, which was further confirmed by ubiquitin expression and periodic acid-Schiff staining. Overall, our data provide a novel link between ongoing neurodegeneration and the formation of corpora amylacea-like structures and calcium deposits in the ischemic hippocampus, suggesting that OPN may play an important role in such processes.

Lipopolysaccharide, Identified Using an Antibody and by PAS Staining, Is Associated With Corpora amylacea and White Matter Injury in Alzheimer's Disease and Aging Brain

Corpora amylacea (CA) increase in number and size with aging. Their origins and functions remain unknown. Previously, we found that Alzheimer's disease (AD) brains have more CA in the periventricular white matter (PVWM) compared to aging controls. In addition, CA is associated with neurodegeneration as indicated by colocalization of degraded myelin basic protein (dMBP) with periodic acid-Schiff (PAS), a CA marker. We also found that bacterial lipopolysaccharide is present in aging brains, with more LPS in AD compared with controls. Periodic acid-Schiff staining is used to identify CA by virtue of their high polysaccharide content. Despite the growing knowledge of CA as a contributor to AD pathology, the molecules that contribute to the polysaccharides in CA are not known. Notably, lipopolysaccharides (LPS) are important cell-surface polysaccharides found in all Gram-negative bacteria. However, it is unknown whether PAS could detect LPS, whether the LPS found in aging brains contribute to the polysaccharide found in CA, and whether LPS associate with myelin injury. In this study, we found that aging brains had a myelin deficit zone (MDZ) adjacent to the ventricles in PVWM. The MDZ contained vesicles, most of which were CA. LPS and dMBP levels were higher in AD than in control brains. LPS was colocalized with dMBP in the vesicles/CA, linking white matter injury with a bacterial pro-inflammatory molecule. The vesicles also contained oxidized fibers, C-reactive protein, NG2, and GALC, markers of oligodendrocyte precursor cells (OPCs) and oligodendrocyte cells (OLs), respectively. The vesicles/CA were surrounded by dense astrocyte processes in control and AD brains. LPS was co-localized with CA by double staining of PAS with LPS in aging brains. The relationship of LPS with PAS staining was confirmed by PAS staining of purified LPS on nitrocellulose membranes. These findings reveal that LPS is one of the polysaccharides found in CA which can be stained with PAS. In addition, vesicles/CA are associated with oxidized and damaged myelin. The LPS in these vesicles/CA may have contributed to this oxidative myelin damage and may have contributed to oxidative stress to OPCs and OLs which could impair the ability to repair damaged myelin in AD and control brains.

Corpora amylacea in human hippocampal brain tissue are intracellular bodies that exhibit a homogeneous distribution of neo-epitopes

Corpora amylacea are spherical bodies of unknown origin and function, which accumulate in the human brain during the aging process and neurodegenerative disorders. In recent work, we reported that they contain some neo-epitopes that are recognized by natural IgMs, revealing a possible link between them and the natural immune system. Here, we performed an ultrastructural study complemented with confocal microscopy in order to shed light on the formation of corpora amylacea and to precisely localize the neo-epitopes. We show that immature corpora amylacea are intracellular astrocytic structures formed by profuse cellular debris and membranous blebs entrapped in a scattered mass of randomly oriented short linear fibers. In mature corpora amylacea, the structure becomes compacted and fibrillary material constitutes the principal component. We also determined that the neo-epitopes were uniformly localized throughout the whole structure. All these observations reinforce the idea that corpora amylacea of human brain are equivalent to another type of polyglucosan bodies named PAS granules, present in mouse brain and originated from degenerative processes. All those findings support the hypothesis that corpora amylacea are involved in the entrapment of damaged materials and non-degradable products and have a role in protective or cleaning mechanisms.

Does abnormal glycogen structure contribute to increased susceptibility to seizures in epilepsy?

Epilepsy is a family of brain disorders with a largely unknown etiology and high percentage of pharmacoresistance. The clinical manifestations of epilepsy are seizures, which originate from aberrant neuronal synchronization and hyperexcitability. Reactive astrocytosis, a hallmark of the epileptic tissue, develops into loss-of-function of glutamine synthetase, impairment of glutamate-glutamine cycle and increase in extracellular and astrocytic glutamate concentration. Here, we argue that chronically elevated intracellular glutamate level in astrocytes is instrumental to alterations in the metabolism of glycogen and leads to the synthesis of polyglucosans. Unaccessibility of glycogen-degrading enzymes to these insoluble molecules compromises the glycogenolysis-dependent reuptake of extracellular K(+) by astrocytes, thereby leading to increased extracellular K(+) and associated membrane depolarization. Based on current knowledge, we propose that the deterioration in structural homogeneity of glycogen particles is relevant to disruption of brain K(+) homeostasis and increased susceptibility to seizures in epilepsy.

Neuronal glycogen synthesis contributes to physiological aging

Glycogen is a branched polymer of glucose and the carbohydrate energy store for animal cells. In the brain, it is essentially found in glial cells, although it is also present in minute amounts in neurons. In humans, loss-of-function mutations in laforin and malin, proteins involved in suppressing glycogen synthesis, induce the presence of high numbers of insoluble polyglucosan bodies in neuronal cells. Known as Lafora bodies (LBs), these deposits result in the aggressive neurodegeneration seen in Lafora’s disease. Polysaccharide-based aggregates, called corpora amylacea (CA), are also present in the neurons of aged human brains. Despite the similarity of CA to LBs, the mechanisms and functional consequences of CA formation are yet unknown. Here, we show that wild-type laboratory mice also accumulate glycogen-based aggregates in the brain as they age. These structures are immunopositive for an array of metabolic and stress-response proteins, some of which were previously shown to aggregate in correlation with age in the human brain and are also present in LBs. Remarkably, these structures and their associated protein aggregates are not present in the aged mouse brain upon genetic ablation of glycogen synthase. Similar genetic intervention in Drosophila prevents the accumulation of glycogen clusters in the neuronal processes of aged flies. Most interestingly, targeted reduction of Drosophila glycogen synthase in neurons improves neurological function with age and extends lifespan. These results demonstrate that neuronal glycogen accumulation contributes to physiological aging and may therefore constitute a key factor regulating age-related neurological decline in humans.

Utilization of lectin-histochemistry in forensic neuropathology: lectin staining provides useful information for postmortem diagnosis in forensic neuropathology

We have investigated the deposition of glycoconjugates in human brain tissue with or without brain disorders. In this review we describe the application of lectin-histochemistry techniques to forensic neuropathology. Lectin staining is able to reveal several kinds of carbohydrate-related depositions in addition to the conventional degenerative changes including senile plaques, neurofibrillary tangles and corpora amylacea. The senile plaques and neurofibrillary tangles were clearly stained by Con A, PSA and GSI lectins, the corpora amylacea which is relevant to repeated brain hypoxia and mitochondrial damage was also easily detected by these and many other kinds of lectins. Amorphous spaces were detected around blood vessels and independently from blood vessels by lectin staining in the white matter from patients with brain disorders or severe edema. The white matter lesions were not considered relevant for forensic pathology, until a large group of cerebral white matter lesions were detected in the elderly with increasing frequency by modern neuro-imaging methods. The spherical deposits were newly detected by lectin staining in the molecular layer of the dentate gyrus of the hippocampal formation chiefly from patients with schizophrenia or cognitive dysfunctions.

New data on the ultrastructure of the corpus amylaceum (polyglucosan body)

During the semiquantitative evaluation of the occurrence of the corpus amylaceum (CA) in a large quantity of autopsy and biopsy material (1,407 cases), electromicroscopical (EM) and scanning EM examinations were carried out on 8 autopsied cases where CA was demonstrated. The EM examinations appeared to underline the astrocytic origin of the CA formation, which is initiated in the astrocytic fiber system by glycogen and other carbohydrate polymers. The biophysics of the development of the CA is indicative of the same mechanisms as for (mainly intracellular) inclusion bodies. The large amount of CA that develops at the predilection sites is a consequence of metabolic damage, a large quantity of cerebrospinal fluid and recurring disturbances in the barrier functions. The abundant CA may cause secondary blood-brain barrier disturbances. This working hypothesis demands further investigations and the continuation of research by modern immunocytochemical and ultrastructural methods recommended.

Probable adult polyglucosan body disease

Adult polyglucosan body disease is a clinicopathologic entity characterized by progressive upper and lower motor neuron dysfunction, sensory loss in the lower extremities, sphincter dysfunction, and occasionally dementia. Pathologically, numerous large polyglucosan bodies are noted in peripheral nerves, cerebral hemispheres, and the spinal cord, as well as in other systemic tissues. We present a case of probable adult polyglucosan body disease based on clinical history and examination, magnetic resonance images, and sural nerve biopsy findings.

Corpora-amylacea and the family of polyglucosan diseases

The history, characters, composition and topography of corpora amylacea (CA) in man and the analogous polyglucosan bodies (PGB) in other species are documented, noting particularly the wide variation in the numbers found with age and in neurological disease. Their origins from both neurons and glia and their probable migrations and ultimate fate are discussed. Their presence is also noted in other organs, particularly in the heart. The occurrence in isolated cases of occasional 'massive' usually focal accumulations of similar polyglucosan bodies in association with certain chronic neurological diseases is noted and the specific conditions Adult Polyglucosan body disease and type IV glycogenosis where they are found throughout the nervous system in great excess is discussed. The distinctive differences of CA from the PGB of Lafora body disease and Bielschowsky body disease are emphasised. When considering their functional roles, a parallel is briefly drawn on the one hand between normal CA and the bodies in the polyglucosan disorders and on the other with the lysosomal system and its associated storage diseases. It is suggested that these two systems are complementary ways by which large, metabolically active cells such as neurons, astrocytes, cardiac myocytes and probably many other cell types, dispose of the products of stressful metabolic events throughout life and the continuing underlying process of aging and degradation of long lived cellular proteins. Each debris disposal system must be regulated in its own way and must inevitably, a priori, be heir to metabolic defects that give rise in each to its own set of metabolic disorders.

Experimental induction of corpora amylacea in adult rat brain

Corpora amylacea (CA) are glycoproteinaceous inclusions that accumulate in astroglia and other brain cells as a function of advancing age and, to an even greater extent, in several human neurodegenerative conditions. The mechanisms responsible for their biogenesis and their subcellular origin(s) remain unclear. We previously demonstrated that the sulfhydryl agent, cysteamine (CSH), promotes the accumulation of CA-like inclusions in cultured rat astroglia. In the present study, we show that subcutaneous administration of CSH to adult rats (150 mg/kg for 6 weeks followed by a 5-week drug-washout period) elicits the accumulation of CA in many cortical and subcortical brain regions. As in the aging human brain and in CSH-treated rat astrocyte cultures, the inclusions are periodic acid-Schiff -positive and are consistently immunostained with antibodies directed against mitochondrial epitopes and ubiquitin. Our findings support our contention that mitochondria are important structural precursors of CA, and that CSH accelerates aging-like processes in rat astroglia both in vitro and in the intact brain.

Corpus amylaceum (polyglucosan body) in the peripheral olfactory system

Peripheral part of the olfactory system (bulb and tract) was investigated for the occurrence of corpus amylaceum (CA) (polyglucosan body) in 296 (281 pathological and 15 control cases) autopsied human brains. No significant differences were found in the incidence between the various age groups above 40 years or between different disease groups and the controls. The predominance of CA in the olfactory tract and its loose correlation with age at this localization over 40 years of age could be resulted by various factors, including the extremely rich astrocytic and capillary network in the intermediate zone, and the proximity of the olfactory tract to the external environment, which may result in the protective role of CA. The role of stress was proved by the HSP-60 positivity of CA.

Experimental induction of corpora amylacea-like inclusions in rat astroglia

Corpora amylacea (CA) are glycoproteinaceous inclusions that accumulate in the human central nervous system during normal ageing, and to an even greater extent in Alzheimer's disease and other neurodegenerative disorders. They are particularly prominent in subpial and subependymal regions, and are most commonly located within astrocytes and their processes. We previously demonstrated that human CA share many tinctorial and histochemical properties in common with Gomori-positive cytoplasmic granules which accumulate in periventricular astrocytes of the ageing vertebrate brain and in rat astroglial cultures exposed to the sulphydryl agent, cysteamine (CSH). In the present study, long-term exposure of neonatal rat astrocyte cultures to CSH resulted in the formation of large spherical, PAS-positive cytoplasmic inclusions which are highly reminiscent of, if not identical to, human CA. As in the case of human CA and Gomori-positive astrocyte granules, the CSH-induced CA-like inclusions exhibit non-enzymatic peroxidase activity and consistent immunolabelling with antibodies directed against the mitochondrial protein, sulphite oxidase. Taken together, our findings suggest that progressive mitochondrial damage and macroautophagy play an important role in the biogenesis of CA (and Gomori-positive granules) in astrocytes of the ageing periventricular brain.

X-ray microprobe analysis of corpora amylacea

Since corpora amylacea is concentrated in the high density fraction in the subcellular fractionation of autopsy brain. It is suspected that inorganic materials accumulate in corpora amylacea. Therefore, elemental analyses of partially purified corpora amylacea from autopsy brain from a patient with Alzheimer's disease and those from brain of a non-demented patient were performed by the X-ray microprobe method. Prominent peaks of sodium, phosphorus, sulphur and chloride were observed, and mapping analyses confirmed that these elements were actually contained within the corpora amylacea. A similar result was obtained using cryostat sections. Corpora amylacea are characteristically distributed along the margin of blood vessels, beneath the pial border of the hippocampus and in the subependymal zones of ventricles of aged brains, namely in the vicinity of blood and cerebrospinal fluid. From this distribution and from the results of the present paper, we suggest that corpora amylacea play a role in the absorption and accumulation of inorganic materials which have been extravasated from blood and cerebrospinal fluid (CSF) and taken up by astrocytes. This may reflect alteration of the blood-brain and blood-CSF barriers in the ageing brain.

Mitochondrial constituents of corpora amylacea and autofluorescent astrocytic inclusions in senescent human brain

Corpora amylacea (CA) are cytoplasmic inclusions that accumulate in human brain in the course of normal aging, and to an even greater extent, in Alzheimer's disease and other neurodegenerative conditions. In senescent and Alzheimer-diseased human brains, astrocytes in limbic and periventricular regions exhibit red autofluorescent inclusions, homologous to Gomori-positive astrocyte granules previously described in the brains of aging rodents and other vertebrates. We have shown that Gomori inclusions in situ and in culture are derived from autophagocytosed mitochondria exhibiting iron-mediated peroxidase activity. In the human brain, the autofluorescent inclusions share many properties with CA. Both types of inclusion progressively accumulate in periventricular regions with advancing age, are largely astrocytic in origin, and contain various heat shock proteins and ubiquitin. Using histochemistry in conjunction with cofocal microscopy, we demonstrated that both CA and the red autofluorescent granules exhibit non-enzymatic peroxidase activity and an affinity for CAH and PAS. The only major divergent histochemical feature between the Gomori-positive astrocyte granules and CA is the presence of orange-red autofluorescence in the former and the absence of endogenous fluorescence in the latter. On the basis of numerous shared topographic and histochemical features, we hypothesized that CA are largely derived from autofluorescent (Gomori-positive) astrocyte granules which reside in periventricular regions of the senescent CNS. Immunofluorescent labeling and laser scanning confocal microscopy demonstrated consistent colocalization of the mitochondrial proteins, sulfite oxidase, and heat shock protein 60, to both CA and the autofluorescent astroglial inclusions. In addition, both CA and the autofluorescent astrocyte granules exhibit staining for DNA which colocalizes to mitochondrial antigens and therefore likely represents mitochondrial nucleic acid in dual-labeled preparations. These observations suggest that a) Gomori-positive astrocyte granules in human brain are homologous to those described in rodents, b) Gomori-positive granules may be structural precursors of CA in senescent human brain, and c) in the aging human brain, degenerate mitochondria within periventricular astrocytes give rise to autofluorescent cytoplasmic granules and corpora amylacea.

Immunochemical identification of ubiquitin and heat-shock proteins in corpora amylacea from normal aged and Alzheimer's disease brains

Corpora amylacea (CA) accumulation in the central nervous system (CNS) is associated with both normal aging and neurodegenerative conditions such as Alzheimer's disease (AD). CA is reported to be primarily composed of glucose polymers, but approximately 4% of the total weight of CA is consistently composed of protein. CA protein resolved on sodium dodecylsulfate-polyacrylamide gel electrophoresis showed a broad range of polypeptides ranging from 24 to 133 kDa, with four abundant bands. Immunoblots of the profile of polypeptides solubilized from purified CA, showed positive ubiquitin (Ub) immunoreactivity for all the bands. Antisera to heat-shock proteins (hsp) 28 and 70 reacted selectively with bands of 30 and 67 kDa. These results show that Ub is associated with the primary protein components of CA and that the polypeptides are likely to be Ub conjugates. Immunostaining experiments were performed to specifically characterize the protein components of CA in brain tissue sections as well as those of CA purified from both AD and normal aged brains. In all cases CA showed positive reactions with antibodies to Ub, with antibodies raised against either paired helical filaments or hsp 28 or 70, the most prominent staining being with antibodies to Ub, hsp 28 or hsp 70. The presence of Ub and hsp 28 and 70, which are actively induced after stress, suggests that accumulation of altered proteins, possibly attributed to an increased frequency of unusual post-translational modifications or to a sustained physiological stress (related to both normal aging and neurodegenerative process), may be involved in the pathogenesis of CA.

Occurrence of polyglucosan bodies in temporal lobe epilepsy

Massive occurrence of polyglucosan bodies (PBs) was found within the surgically removed temporal lobe of a 34 year old woman with complex partial seizures. This peculiar feature is very unusual in neuropathological examinations of epileptogenic foci. This patient could not be included in any of the classic diseases in which PBs are found. She exhibited a localised form of glycogen storage disease.

Ubiquitin is a component of polypeptides purified from corpora amylacea of aged human brain

Corpora amylacea (CA) are one of the conspicuous features of brain tissue in normal aging and neurodegenerative diseases. Quantitative protein determination of purified CA revealed a protein content of about 4% of total weight. Qualitative protein analysis revealed a broad range of polypeptides, with four being more abundant. High performance liquid chromatography (HPLC) fractionation of this protein material showed four peaks which are related to the four major polypeptides with molecular weights of 24 KD, 42 KD, 94 KD, and 133 KD. Amino acid content analysis of the 24 KD, 42 KD and 94 KD polypeptides indicated that distinct protein species are involved. N-terminal amino acid sequence analysis of the 24 KD and 42 KD polypeptides revealed in both cases homology with the N-terminal sequence of human ubiquitin.

Lectin histochemistry of canine polyglucosan bodies

Lectin histochemistry was investigated to identify sugar residues of the polyglucosan bodies of canine brain, spinal cord and caecum. The polyglucosan bodies in the brain and spinal cord stained with concanavalin A (ConA) but not with soybean agglutinin, wheat germ agglutinin, peanut agglutinin, Dolichos biflorus agglutinin, Ricinus communis agglutinin and Ulex europaeus agglutinin. Caecum polyglucosan bodies, however, did not stain with any of the seven lectins employed. After periodate oxidation, paradoxical ConA staining was observed in the polyglucosan bodies of the brain, spinal cord and caecum. These results indicate that polyglucosan bodies contain mannose and glucose residues and suggest that the component of polyglucosan bodies is partially derived from rough endoplasmic reticulum, the Golgi apparatus and hypolemmal cisternae.

Glycogen accumulations in the cerebral cortex in Alzheimer's disease

The fine structure of granular glycogen bodies (GGB) within the grey matter of the temporal cortex of 11 patients with Alzheimer's disease is described. GGB measure up to 50 microns in diameter and consist of densely packed alpha or beta glycogen granules (never both), neither of which are membrane bound. They were noted in axons, both myelinated and unmyelinated (sometimes close to the dystrophic neurites of senile plaques), and also in other processes of indeterminate origin. Their appearance may relate to disturbances of axonal transport resulting from damage to terminals within evolving senile plaques.

Glycogen accumulation of the aging human brain

We describe light- and electron-microscopically a new type of intracytoplasmatic inclusions within cell processes of the cerebral cortex and the underlying white matter. These structures measure 5-50 micron in diameter and consist almost exclusively of densely packed alpha- or beta-glycogen granules, which never occur together in any single structure. Within their periphery, electron-dense amorphous spots and cell organelles, especially mitochondria, were seen. No membrane-bound glycogen was observed. We propose to call them granular glycogen bodies. They occur in 4 of 7 examined postmortem specimens of the cerebral cortex of people older than 60 years of age. They were not found in 4 younger controls aged 26-48. Their appearance may reflect a distinct turnover disorder of carbohydrate metabolism, which becomes manifest under diverse pathologic conditions and in the normal aging process.

Pleomorphic intra-neuronal polyglucosan bodies mainly restricted to the pallidium. A case report

rare case with pleomorphic intra-neuronal polyglucosan bodies is reported. A 45-year-old man died of gastric carcinoma with extensive visceral involvement. The autopsy showed numerous intra-neural pleomorphic PAS-positive deposits reminiscent of Bielschowsky bodies in the lateral segments of the pallidum, substantia nigra, and brain stem on both sides. Their histochemical properties were consistent with polyglucosan. The bodies were ultrastructurally composed of filamentous structures and seen in perikarya, axons, and dendrites. Occasionally, spotty electron-dense material was seen in the center of the bodies. The filaments were selectively stained with thiocarbohydrazide method after Thiéry, indicating their chief component as glucose polymers. The bodies are compared with Bielschowsky bodies, Lafora bodies, corpora amylacea, and related bodies, and their nature and significance are briefly discussed.

Polyglucosan bodies in the digestive tract of the aged dog

In our recent studies on aging phenomena in animals, polyglucosan bodies (PGB) were found within the smooth muscle in the digestive tract of aged dogs without neurologic signs. PGB were basophilic, round, or oval bodies which appeared to have a homogeneous or concentric shape. Their histochemical properties were characterized by the presence of glucose polymers (polyglucosan). Electron microscopy revealed that PGB were composed mainly of irregularly clustered, short branching filaments measuring about 90 A in width. PGB were histochemically and ultrastructurally identical to the previously reported Lafora-like bodies in the CNS of aged dogs. PGB were found in all aged dogs and were disseminated throughout the digestive tract, especially in the cecum.