Purkinje Cell Layer Research Articles

Potential Therapeutic Effect of Hematopoietic Stem Cells on Cerebellar Ataxia in Adult Female Rats Subjected to Cerebellar Damage by Monosodium Glutamate

Background: Research evidence has indicated that monosodium glutamate (MSG) consumption produces certain deleterious effects on the cerebellum of adult rats at high doses which can consequently affect cerebellar function. The use of stem cells in nervous system disorders is a growing field, which in numerous reports has shown promising results in the restoration of neurological function. Aim: To compare the effect of injection of human umbilical cord blood CD34+ stem cells versus CD34- fraction in a rat model of cerebellar damage induced by monosodium glutamate. Methods: Forty adult female albino rats were equally randomized into 4 groups: group I served as control, group II received MSG, group III received MSG followed by CD34+ stem cell separated from umbilical cord blood of human male fetuses, group IV received MSG followed by the CD34- fraction. At the end of the experiment, all rats were subjected to assessment of motor function, histological and immunohistochemical techniques as well as a polymerase chain reaction analysis of male-specific Sry gene. Results: Group II showed a significant decrease in the mean number of Purkinje cells and cells of the molecular layer. Nissl’s granules and length of dendrites of Purkinje cells were markedly decreased. Marked increase of GFAP immunoexpression in astrocytes was also detected. Group III stem cells showed improvement in motor function after 4 weeks of treatment. The CD34- group (IV) showed more increase in the number of cells in the molecular, granular and Purkinje cell layers as well as an increase in Nissl’s granules and Purkinje cell dendrite length compared to CD34+ stem cell group (III). There was also a significant decrease in optical density of GFAP immunoexpression of the CD 34- group compared to both MSG and CD34+ groups. The Sry gene was not detected in either of the CD34+ and CD34- groups implying that the improvement happened without homing of stem cells in the cerebellum. Conclusion: Both CD34 -ve and CD34+ve stem cells improved cerebellar structure and function against damage induced by monosodium glutamate; however CD34- stem cells showed more improvement than CD34+ stem cells.

Sequential accumulation of iron in glial cells during chicken cerebellar development

Iron is an essential, but potentially harmful, metal in the brain. In normal brain, iron has been reported to accumulate mainly in glial cells and occasionally in neurons in some particular nuclei. However, the majority of investigations have targeted the adult brain. Here, we investigated spatiotemporal localization of iron in developing and adult chicken cerebellum using iron histochemistry. Iron reactivity was not detected in the chick cerebellum until embryonic day 12. Iron accumulation was first found in mature myelinating oligodendrocytes located in the inner part of the cerebellar folium at embryonic day 14. From embryonic day 20, iron-positive mature myelinating oligodendrocytes were localized in the white matter and the granular layer. From post-hatching day 2, iron accumulation was observed in Bergmann glia in the Purkinje cell layer as well as in mature myelinating oligodendrocytes. Iron accumulation in microglia was observed in the granular and molecular layers at post-hatching month 12. Our data indicate that during cerebellar development iron is accumulated in a unique sequence according to individual requirements or microenvironmental demands.

Aetiopathogenesis of cerebral ischemia in young Turkish patients

Aetiopathogenesis of cerebral ischemia in young Turkish patients

Effect of aflatoxin-B1 on rat cerebellar cortex

Introduction Aflatoxin contamination of foods is a worldwide problem, especially in developing countries. The effects of aflatoxins on the cerebellum are not well studied. Aim of the study The aim of the present study was to evaluate the possible neurotoxic effects of aflatoxin B1 on the cerebellar cortex of adult male albino rats. Materials and methods A total of 30 adult female albino rats were used. They were divided into two groups. Group I (10 animals) was allowed water ad libitum and fed a standard diet (negative control). Group II (20 animals) was administered 5 ml aflatoxin B1 orally by a gastric tube every week for 8 consecutive weeks. Samples from the cerebella were taken and processed for light and electron microscopic investigation. Results Light microscopic examination of the cerebellar cortex of aflatoxin-treated animals showed its prominent neurotoxic effect on the Purkinje cell layer, with less effect on the granular and molecular layers. Glial fibrillary acidic protein-positive cells were more abundant in the three cortical layers of treated animals compared with the control animals. Ultrastructural study of the cerebellum of the aflatoxin-treated group showed dilated Golgi complex and accumulation of secondary lysosomes in association with nuclear shrinkage and irregularity within Purkinje cells. Many myelinated nerve fibers and nerve cell processes in the molecular and granular layer belonging to the affected nerve cells showed degenerative changes. Conclusion It could be concluded according to this study that aflatoxin B1 has a neurotoxic effect on the cerebellar cortex of adult female albino rats.

Intact Numbers of Cerebellar Purkinje and Granule Cells in Sudden Infant Death Syndrome

Despite much research during recent decades, the etiology and pathogenesis of sudden infant death syndrome (SIDS) remain unknown. Because of the role of the cerebellum in respiratory and cardiovascular control, it has been proposed that it plays an important role in the pathogenesis of SIDS. To date, 5 postmortem studies on the cerebellum of SIDS cases have yielded conflicting results. Using a rigorous design-based stereologic approach, we investigated postmortem cerebella from 9 SIDS patients who died between 2 and 10 months of age and from 9 age- and sex-matched control children. Neither the volumes of the cerebellar external granule cell layer, molecular layer, internal granule cell layer (including the Purkinje cell layer), and white matter nor the total numbers of Purkinje cells, granule cells in the internal granule cell layer, and the number of granule cells per Purkinje cell showed statistically significant differences between the SIDS cases and the controls. Based on these observations, we conclude that structural alterations in cerebellar development are not involved in the etiology and pathogenesis of SIDS.

Quantification of cerebellar hemispheric purkinje cell linear density: 32 ET cases versus 16 controls

Although essential tremor (ET) is among the most prevalent neurological diseases, its precise pathogenesis is not understood. Purkinje cell loss has been observed in some studies and is the focus of interest and debate. Expressing these data as Purkinje cells/layer length allows one to adjust for the inherent curved nature of the cerebellar folia. Capitalizing on the Essential Tremor Centralized Brain Repository, we quantified Purkinje cell linear density in cases versus controls. Free-floating 100-μm parasagittal cerebellar hemispheric sections were subjected to rabbit polyclonal anti-Calbindin D28k antibody, and 10 random fields/brain were selected for quantification of Purkinje cells/mm(-1) Purkinje cell layer. Purkinje cell linear density was lower in 32 ET cases than in16 controls (1.14 ± 0.32 vs. 1.35 ± 0.31/mm(-1) , P = 0.03). Purkinje cell linear density was inversely associated with torpedo count (r = -0.38, P = 0.028). The current sample of ET cases demonstrates a reduction in Purkinje cell number relative to that of controls. Greater Purkinje cell axonal remodeling (torpedoes) was found in individuals who had the most Purkinje cell drop out. The role of Purkinje cell loss in the pathogenesis of this disorder merits additional study.

Localization of CGRP Receptor Components, CGRP, and Receptor Binding Sites in Human and Rhesus Cerebellar Cortex

The cerebellum is classically considered to be mainly involved in motor processing, but studies have suggested several other functions, including pain processing. Calcitonin-gene-related peptide (CGRP) is a neuropeptide involved in migraine pathology, where there is elevated release of CGRP during migraine attacks and CGRP receptor antagonists have antimigraine efficacy. In the present study, we examined CGRP and CGRP receptor binding sites and protein expression in primate cerebellar cortex. Additionally, mRNA expression of the CGRP receptor components, calcitonin receptor-like receptor (CLR) and receptor activity modifying protein 1 (RAMP1), was examined. In addition, expression of procalcitonin was studied. We observed high [(3)H]MK-3207 (CGRP receptor antagonist) binding densities in the molecular layer of rhesus cerebellar cortex; however, due to the limit of resolution of the autoradiographic image the exact cellular localization could not be determined. Similarly, [(125)I]CGRP binding was observed in the molecular layer and Purkinje cell layer of human cerebellum. CLR and RAMP1 mRNA was expressed within the Purkinje cell layer and some expression was found in the molecular layer. Immunofluorescence revealed expression of CGRP, CLR, and RAMP1 in the Purkinje cells and in cells in the molecular layer. Procalcitonin was found in the same localization. Recent research in the biology of cerebellum indicates that it may have a role in nociception. For the first time we have identified CGRP and CGRP receptor binding sites together with CGRP receptor expression through protein and mRNA localization in primate cerebellar cortex. These results point toward a functional role of CGRP in cerebellum. Further efforts are needed to evaluate this.

Activation of Liver X Receptor Is Protective Against Ethanol-Induced Developmental Impairment of Bergmann Glia and Purkinje Neurons in the Mouse Cerebellum

Cerebellar Purkinje cell and granule cell development are coordinated by Bergmann glia, and are particularly sensitive to ethanol (EtOH) exposure. The liver X receptor (LXR) plays important roles in Bergmann glial development. However, the effect of LXR activation on EtOH-mediated impairment of Bergmann glia and subsequently on Purkinje cell dendritogenesis remains undetermined. Therefore, using immunohistochemistry, quantitative real-time PCR and Western blot, we tested the possible protection of LXR agonist T0901317 (T0) on Bergmann glia and Purkinje cell dendritogenesis in mice exposed to ethanol. Results showed that a brief exposure of EtOH on postnatal day (PD 5) significantly decreased the average body weight of mice at PD 6 without alteration in the brain weight. In EtOH-exposed mice, the number of migrating granule cells in the molecular layer was significantly decreased, and this effect was attenuated by pretreatment of T0. EtOH exposure also resulted in the significant reduction of calbindin-labeled Purkinje cells, their maximum dendrite length, and impairment of Purkinje cell dendritogenesis. Furthermore, EtOH induced the activation of microglia in the Purkinje cell layer and impaired the development of Bergmann glia. However, pretreatment of T0 effectively blocked all of these responses. These responses were found to be mediated by the inhibition of upregulated levels of β-catenin and transcription factor LEF1 in the cerebellum. Overall, the results suggest that activating LXRs on postnatal mice exposed to EtOH is protective to Bergmann glia, and thus may play a critical role in preventing EtOH-induced defects during cerebellar development.

N-methyl-N-nitrosourea-induced cerebellar hypoplasia in rats: Effect of arachidonic acid supplementation during the gestational, lactational and post-weaning periods

Arachidonic acid (AA) is a fatty acid that is important for visual and brain development and is commonly added as a functional food ingredient to commercial infant formulas worldwide. However, few studies have examined whether AA supplementation during neonatal life has an effect on neuronal abnormalities. In the present study, the effect of dietary AA supplementation in dams during gestation and lactation was investigated by examining N-methyl-N-nitrosourea (MNU)-induced cerebellar hypoplasia in young Lewis rats. Dams were fed a 2.0% AA diet or a basal diet (<0.01% AA). At birth (postnatal day 0), male and female pups received a single intraperitoneal injection of 35 mg/kg MNU or vehicle. Brain weights were measured and a morphological analysis of macroscopic and histological specimens was conducted after 7, 14, 21, 28 and 60 days. Irrespective of whether the rats had been fed an AA diet, the brain weights of the MNU-treated rats, particularly the weights of the cerebellum, were decreased compared with those of the MNU-untreated rats from the 14th day following the MNU injection. Macroscopic reductions in the cerebellar length and/or width and histologically observed reductions in cerebellar vertex height and/or cortex width were also detected in the MNU-treated rats, irrespective of whether the rats had been fed with AA. Histopathologically, the MNU-treated rats (irrespective of AA supplementation) exhibited disorganization of the cerebellar cortex and disarrangement of the cortical layers (loss and/or disturbance of the molecular, Purkinje and granular cell layers). There were no significant differences in any parameters among the MNU-treated rats, irrespective of whether the rats had been fed an AA diet. In conclusion, an AA-rich diet for dams during gestation and lactation did not modify MNU-induced cerebellar hypoplasia in their offspring.

The du2J mouse model of ataxia and absence epilepsy has deficient cannabinoid CB1 receptor‐mediated signalling

Cerebellar ataxias are a group of progressive, debilitating diseases often associated with abnormal Purkinje cell (PC) firing and/or degeneration. Many animal models of cerebellar ataxia display abnormalities in Ca²⁺ channel function. The 'ducky' du(2J) mouse model of ataxia and absence epilepsy represents a clean knock-out of the auxiliary Ca²⁺ channel subunit α2δ-2, and has been associated with deficient Ca²⁺ channel function in the cerebellar cortex. Here, we investigate effects of du(2J) mutation on PC layer (PCL) and granule cell layer (GCL) neuronal spiking activity and, also, inhibitory neurotransmission at interneurone-Purkinje cell (IN-PC) synapses. Increased neuronal firing irregularity was seen in the PCL and, to a less marked extent, in the GCL in du(2J)/du(2J), but not +/du(2J), mice; these data suggest that the ataxic phenotype is associated with lack of precision of PC firing, that may also impinge on GC activity and requires expression of two du(2J) alleles to manifest fully. The du(2J) mutation had no clear effect on spontaneous inhibitory postsynaptic current (sIPSC) frequency at IN-PC synapses, but was associated with increased sIPSC amplitudes. du(2J) mutation ablated cannabinoid CB1 receptor (CB1R)-mediated modulation of spontaneous neuronal spike firing and CB1R-mediated presynaptic inhibition of synaptic transmission at IN-PC synapses in both +/du(2J) and du(2J)/du(2J) mutants, effects that occurred in the absence of changes in CB1R expression. These results demonstrate that the du(2J) ataxia model is associated with deficient CB1R signalling in the cerebellar cortex, putatively linked with compromised Ca²⁺ channel activity and the ataxic phenotype.

Inactivation of Ceramide Synthase 6 in Mice Results in an Altered Sphingolipid Metabolism and Behavioral Abnormalities

The N-acyl chain length of ceramides is determined by the specificity of different ceramide synthases (CerS). The CerS family in mammals consists of six members with different substrate specificities and expression patterns. We have generated and characterized a mouse line harboring an enzymatically inactive ceramide synthase 6 (CerS6KO) gene and lacz reporter cDNA coding for β-galactosidase directed by the CerS6 promoter. These mice display a decrease in C16:0 containing sphingolipids. Relative to wild type tissues the amount of C16:0 containing sphingomyelin in kidney is ∼35%, whereas we find a reduction of C16:0 ceramide content in the small intestine to about 25%. The CerS6KO mice show behavioral abnormalities including a clasping abnormality of their hind limbs and a habituation deficit. LacZ reporter expression in the brain reveals CerS6 expression in hippocampus, cortex, and the Purkinje cell layer of the cerebellum. Using newly developed antibodies that specifically recognize the CerS6 protein we show that the endogenous CerS6 protein is N-glycosylated and expressed in several tissues of mice, mainly kidney, small and large intestine, and brain.

Full-scale structural model of the Inferior Olive and Olivocerebellar projection constructed from constraining meshes and directed growth

Constructing a full scale model of a brain structure demands several considerations. First, to be useful, the model must be of a computable size. Previously, we mapped the computation of dense multicompartmental models of neural tissue to the Blue Gene/P supercomputer at ~250 neurons per node of this machine. A ~30k neuron structure such as the Inferior Olive [1] is therefore well within the limits of today's machines, and so we aimed to build a structural model of this structure that could appropriately constrain a hypothetical physiological model. Next, to constrain olivary physiology appropriately with our structural model, we included axons in addition to the usual structural constraints on neuronal integration imposed by dendritic morphologies, because spike generation and bursting properties of olivary neurons depend on axonal length [2]. To create our structural model, we first constructed a 3-D mesh from a segmented stack of slices through the granule cell and Purkinje cell layers of the rat cerebellum. Through this mesh, we required olivocerebellar projections and climbing fibers to course (Figure 1A, 1B) to arrive at and create Purkinje cell ramifications [3]. This method generates our distribution of axon lengths. Figure 1 A. Bounding triangular meshes for cerebellar granule cell layer (top) and inferior olivary nucleus (bottom), embedded in brain coordinates. B. Granule cell layer mesh constrains waypoint-based axonal growth into the Purkinje cell layer of olivary neurons, ... Finally, we constrained dendritic morphology using a version of our previous model of self-referentially biased dendritic growth [4], modified to give a better match to olivary neuron morphology. This new model takes as input a 3-D mesh, which approximates nucleus boundaries using measurements of the Inferior Olive size and composition [1]. As before, we generated dendritic arbors to match morphological measures [5], but determined that their characteristic spiral shape depends on a repulsive force from the bounding mesh. The full 24,815 dendritic arbors were then generated on 64 nodes of Blue Gene/Q, running 8 tasks/node, and 8 threads/task in <15 mins. (Figure ​(Figure1C).1C). We discuss future physiological models, including gap junctions, constrained by this structural model.

Delta-like 1 regulates Bergmann glial monolayer formation during cerebellar development

BackgroundBergmann glia (BG) are unipolar cerebellar astrocytes. The somata of mature BG reside in the Purkinje cell layer and extend radially arranged processes to the pial surface. BG have multiple branched processes, which enwrap the synapses of Purkinje cell dendrites. They migrate from the ventricular zone and align next to the Purkinje cell layer during development. Previously, we reported that Notch1, Notch2, and RBPj genes in the BG play crucial roles in the monolayer formation and morphogenesis of BG. However, it remains to be determined which ligand activates Nocth1 and Notch 2 on BG. Delta-like 1 (Dll1) is a major ligand of Notch receptors that is expressed in the developing cerebellum.ResultsIn this study, we used human glial fibrillary acidic protein (hGFAP) promoter-driven Cre-mediated recombination to delete Dll1 in BG. Dll1-conditional mutant mice showed disorganization of Bergmann fibers, ectopic localization of BG in the molecular layer and a reduction in the number of BG.ConclusionThese results suggest that Dll1 is required for the formation of the BG layer and its morphological maturation, apparently through a Notch1/2-RBPj dependent signaling pathway.

SEMA3A Signaling Controls Layer-Specific Interneuron Branching in the Cerebellum

GABAergic interneurons regulate the balance and dynamics of neural circuits, in part, by elaborating their strategically placed axon branches that innervate specific cellular and subcellular targets. However, the molecular mechanisms that regulate target-directed GABAergic axon branching are not well understood. Here we show that the secreted axon guidance molecule, SEMA3A, expressed locally by Purkinje cells, regulates cerebellar basket cell axon branching through its cognate receptor Neuropilin-1 (NRP1). SEMA3A was specifically localized and enriched in the Purkinje cell layer (PCL). In sema3A(-/-) and nrp1(sema-/sema-) mice lacking SEMA3A-binding domains, basket axon branching in PCL was reduced. We demonstrate that SEMA3A-induced axon branching was dependent on local recruitment of soluble guanylyl cyclase (sGC) to the plasma membrane of basket cells, and sGC subcellular trafficking was regulated by the Src kinase FYN. In fyn-deficient mice, basket axon terminal branching was reduced in PCL, but not in the molecular layer. These results demonstrate a critical role of local SEMA3A signaling in layer-specific axonal branching, which contributes to target innervation.

Distribution and expression of Kirre, an IgSF molecule, during postnatal development of rat cerebellum

Immunoglobulin superfamily (IgSF) molecules are actively involved in cell-cell adhesion, neuronal migration, axonal guidance and synapse formation in the nervous system. Kirre, as a member of this family, has been implicated in mammalian neuronal differentiation and development. Although the distribution of rKirre (a rat homologue of Drosophila Kirre) mRNA was previously analyzed in adult rat cerebellum by in situ hybridization, the expression levels of transcript and protein were not well studied. Here, we showed that the expressions of rKirre mRNA and protein significantly increased during postnatal development of rat cerebellum. rKirre mRNA was mainly expressed in the granular layers and Purkinje cell layer in the developing cerebellum, revealing a possible involvement of rKirre in granule cell migration and Purkinje cell development. An essential relationship between rKirre and Purkinje cells was implied by the co-localization of rKirre and NF-200 on the cell bodies of Purkinje cells. These results suggest that rKirre may play a potential role in postnatal developing rat cerebellum.

Autopsy Report of a 7-Year Old Patient with the Mosaic Trisomy 13

We present here a long survival case of a patient with the mosaic form of trisomy 13 who died of aspiration pneumonia at the age of 7 years and 4 months. The autopsy revealed olfactory aplasia and fenestration of the septum pellucidum, and dilated lateral ventricles and atrophic hippocampus. Furthermore, there were numerous “torpedos” (i.e., swollen fusiform Purkinje cell axons), mostly in the granular layer underneath the Purkinje cell layer, and, occasionally, in the granular layer. Similar neuropathological findings have been reported in elderly cases of essential tremor, Parkinson’s disease, or Alzheimer’s disease. Precise mechanism for this axonal change is still unclear. These pathological changes have never previously been reported in the literature on trisomy 13, and the present patient is one of the oldest autopsied individuals with the mosaic trisomy 13.

Cerebellar degeneration in lurcher mice under confocal laser scanning microscope

Lurcher mutant mice represent a natural model of genetically-determined olivocerebellar degeneration caused by a mutation in the δ2 glutamate receptor gene. They suffer from progressive postnatal loss of cerebellar Purkinje cells and a decrease of granule cells and inferior olive neurons. Their wild type littermates serve as healthy controls. A confocal laser scanning microscope was used aiming investigation the dynamics of changes in the cerebellar cortex of Lurcher and wild type mice derived from two strains during the period of 8-21 postnatal days. Fluorescent double-staining was used to visualize mainly the Purkinje cells in cerebellar slices. In wild types, only normal Purkinje cells of round or regular drop-shaped were present, when staining intensity of other individual cell structures differed in dependence on the age of the animal. In Lurcher mutants, there were still some normal-shaped cells. Nevertheless, depending on the animal's age, a wide variety of stages of the cell degeneration were depicted. The main characteristics of Purkinje cell degeneration in the early stage are: disruption of the continuity of the Purkinje cell layer, dark spots in cell nuclei and an irregular coloring of the cytoplasm. Later, the cells and their nuclei were deformed, often with two main dendrites sprouting from the cell body. Finally, the cell and nucleus margins were unclear, dendrites were significantly thickened, showing signs of shrinkage and fragmentation. Cell nucleoli underwent changes in number and appearance. No differences between the Lurcher mice of both strains (C3H and B6CBA) under examination were found.

Cerebellar Purkinje Cells Exhibit Increased Expression of HMGB-1 and Apoptosis in Congenital Hydrocephalic H-Tx Rats

Highly integrated anatomic and functional interactions between the cerebrum and the cerebellum during development have been reported. In our previous study, we conducted a proteome analysis to identify the proteins present in the congenital noncommunicating hydrocephalus in the cerebellum. We found higher expression of high-mobility group box-1 protein (HMGB-1) in hydrocephalic H-Tx rats. We studied the expression pattern of HMGB-1 in the cerebellum. We studied congenital hydrocephalic H-Tx rats aged 1 day and 7 days along with age-matched nonhydrocephalic H-Tx and Sprague-Dawley rats as controls. Gene and protein expressions of HMGB-1 in the cerebellum were assayed by real-time polymerase chain reaction and Western blotting, respectively; furthermore, immunohistochemical analyses were performed by using HMGB-1 (indicator of apoptosis), single-stranded DNA; adhesion factor related to cell migration, HNK-1; and the Purkinje cell-specific antibody, calbindin. Cytoplasmic HMGB-1 expression observed in Purkinje cells in the 1-day-old hydrocephalic group was stronger than that in the nonhydrocephalic and Sprague-Dawley groups. Double fluorescent staining with single-stranded DNA confirmed that Purkinje cells were undergoing apoptosis. HNK-1 expression was lower in the Purkinje cell layer in the 7-day-old rats in the hydrocephalic group, and Purkinje cells were disrupted in comparison with the control groups. Morphological changes in the cerebellum were observed in the 7-day-old rats in the hydrocephalic group in comparison with the control groups. Our results suggest that cerebellar neuronal cell damage in the early postnatal period may be related to the higher expression of HMGB-1 in the Purkinje cells.

An autopsied case of progressive supranuclear palsy presenting with cerebellar ataxia and severe cerebellar involvement

A Japanese male patient presented with gait disturbance at the age of 69 years. His principal symptom was cerebellar ataxia for several years. He was initially diagnosed as having olivopontocerebellar atrophy because dysarthria and ataxia gradually developed, and head CT scan showed apparent atrophy of the cerebellum and brainstem and dilatation of the fourth ventricle. Later, he showed vertical gaze palsy, dysphagia, retrocollis, parkinsonism, axial dominant rigidity and grasp reflex, and therefore, the diagnosis was modified to progressive supranuclear palsy (PSP). Progressive atrophy of the frontotemporal lobe, cerebellum and brainstem, and dilatation of the lateral, third and fourth ventricles were evident on MRI. Gastrostomy and tracheotomy were performed 9 and 10 years after onset, respectively, and the patient died after 11 years disease duration. At autopsy the brain weighed 1000 g and showed atrophy of the frontotemporal lobe, cerebellum and brainstem. Neurofibrillary tangles, mainly globose-type revealed by Gallyas-Braak silver staining, were extensively observed in the cerebral cortex and subcortical grey matter. Numerous glial fibrillary tangles, including tuft-shaped astrocytes and coiled bodies, and extensive argyrophilic threads were also recognized, particularly in the frontal lobe, basal ganglia, cerebellar white matter, brainstem and spinal cord. The Purkinje cell layer showed severe neuron loss with Bergmann's gliosis, and the dentate nucleus showed severe neuron loss with grumose degeneration. Tau-positive/Gallyas-positive inclusions in the Purkinje cells and the glial cells of the Purkinje cell layer were observed. Pathological findings of the present patient were consistent with the diagnosis of PSP, but the olivopontocerebellar involvement, particularly in the cerebellum, was generally more severe, and the quantity of tau-positive/Gallyas-positive structures were more abundant than in typical PSP cases. The existence of a distinct, rare PSP subtype with severe olivopontocerebellar involvement, "PSP-C", which tends to be clinically misdiagnosed as spinocerebellar degeneration in the early disease stage, is noteworthy. The present case corresponded to this rare subtype of PSP.

An autopsied case of Creutzfeldt‐Jakob disease with mutation in the prion protein gene codon 232 and type 1+2 prion protein

A 68-year-old Japanese man gradually showed abnormal behavior and gait disturbance with bradykinesia. Slowly progressive dementia, including memory disturbance and disorientation, was also observed. Cerebral cortical hyperintensity on diffusion-weighted MRI was observed 6 months after onset. The patient progressed to an akinetic mutism state with mild myoclonus, and atypical periodic sharp-wave complexes were observed by electroencephalogram 13 months after onset. He was clinically suspected of having atypical CJD and died after 19 months total disease duration. The brain weighed 1160 g and showed mild atrophy of the cerebrum and cerebellum with ventricular dilatation. Spongiform changes with varying vacuole size and gliosis was extensive in the cerebral cortex and basal ganglia. Neuron loss in the cerebral cortex, basal ganglia and thalamus was relatively mild. The cerebellum showed mild spongiform changes of the molecular layer and mild neuron loss in the Purkinje cell layer. PrP immunostaining showed mainly coarse-type combined with diffuse synaptic-type PrP deposition in the cerebral gray matter. Some perivacuolar-type PrP deposition was also present. Numerous plaque-type PrP depositions were observed in the molecular layer of the cerebellum. Analysis of the PrP gene revealed a methionine-to-arginine (Met-to-Arg) substitution at codon 232 (M232R) with Met homozygosity at codon 129. Western blot analysis of protease-resistant PrP indicated type 2 dominant PrP combined with type 1. Genetic CJD with M232R substitution in the PrP gene has only been reported in Japan. Although two clinical phenotypes (rapid-type and slow-type) were suggested in the M232R CJD cases (despite the presence of the same PrP genotype), the pathological and molecular backgrounds have not been well understood because there have only been a few autopsied case reports. This is the first case report of M232R CJD presenting with 1 + 2 PrP.