Clinical Neuroscience

[EXPERIMENTAL DEMYELINATION CAUSED BY PRIMARY OLIGODENDROCYTE DYSTROPHY Regional distribution of the lesions in the nervous system of mice brain]

KOMOLY Sámuel

JANUARY 20, 2005

Clinical Neuroscience - 2005;58(01-02)

[Background and purpose - Heterogeneity of multiple sclerosis lesions has been recently indicated: In addition to T-cell-mediated or T-cell plus antibody-mediated autoimmune mechanisms (patterns I-II) two other patterns (III-IV) were described. Patterns III-IV are characterized by primary oligodendrocyte dystrophy, reminiscent of virus- or toxin-induced demyelination rather than autoimmunity. It was described more than 30 years ago that dietary application of a copper-chelating agent called cuprizone results in primary oligodendrocyte degeneration which is followed by demyelination. The aim of the present study was to examine the regional distribution of cuprizone induced oligodendrocyte dystrophy and demyelination in the nervous system of mice. Material a methods - Demyelination was induced in male weanling Swis-Webster mice by feeding them on a diet containing 0.6% (W/W) cuprizone bis(cyclohexanone)-oxalyldihydrazone (G. F. Smith Chemical, Columbus OH) for 8 weeks. Animals were sacrificed after 3, 7, 14, 27, 35, 56 days of cuprizone administration. Samples were taken from corpus callosum, anterior commissure, optic nerve, cervical spinal cord and sciatic nerve. Samples were examined by immunohistochemistry, in situ hybridization for myelin proteins and myelin protein mRNA-s, respectively. Conventional neuropathological stainings and electron microscopy was also performed. Results - Oligodendrocyte degeneration and demyelination followed a particular standard pattern in the central nervous system. Profound myelin loss developed in the superior cerebellar peduncle, anterior comissure and corpus callosum, whereas the optic nerves, velum medullare anterior and spinal cord showed little or no demyelination. Sciatic nerves were unaffected. No infiltration by lymphocytes or blood-brain barrier damage was observed during cuprizone treatment. Conclusion - Cuprizone induced oligodendrocyte damage and demyelination follows a particular standard pattern in the central nervous system of mice. Cuprizone induced demyelination might be considered as a model for human demyelinating disorders with primary oligodendrocyte dystrophy and apoptosis.]

COMMENTS

0 comments

Further articles in this publication

Clinical Neuroscience

[CALPAIN-3 GENE DEFECT CAUSING LIMB GIRD MUSCULAR DYSTROPHY IN A HUNGARIAN FAMILY]

HORVÁTH Rita, MAGGIE C. Walter, HANNS Lochmüller, HÜBNER Angela, KARCAGI Veronika, PIKÓ Henriett, TÍMÁR László, KOMOLY Sámuel

[Limb gird muscular dystrophies (LGMD2) are a clinically and genetically heterogeneous group of hereditary diseases with autosomal recessive trait, characterized by progressive atrophy and weakness predominantly in the proximal limb muscles. The authors present clinical, histological, immunohistochemical and immunoblot results of two sisters suffering from so far unclassified autosomal recessive limb girdle muscular dystrophy. Haplotype analysis for genes possibly involved in autosomal recessive limb girdle muscular dystrophies was performed in the genetically informative family. All of the results pointed to a molecular genetic defect of the calpain-3 (CAPN3) gene. Direct sequencing of the CAPN3 gene revealed compound hetereozygous state for two mutations previously described in association with limb girdle muscular dystrophy, proving pathogenity. The authors would like to emphasize the importance of the above described combined strategy in diagnosing limb girdle muscular dystrophies.]

Clinical Neuroscience

[Vécsei L. (ed.): Frontiers in Clinical Neuroscience]

KOMOLY Sámuel

Clinical Neuroscience

[DIZZINESS - VERTIGO WARNING SYMPTOMS IN VERTEBROBASILAR ISCHEMIA PART II.]

FAZEKAS András

[Dizziness and vertigo - like headache - are the most common complaints which lead patients to visit the doctor. In spite of the headache - which may be primary (e.g. migraine) or symptomatic - dizziness and vertigo do not appear to be a separate nosologic entity but rather the symptoms of several neurological disorders. For differential diagnosis, interdisciplinary thinking and activity is needed because the vestibular, neurological and psychiatric disorders might have a common role in the development of symptoms and further overlapping can also occur. The vascular disorders of the vertebrobasilar system are discussed in detail in this review. The importance, occurrence and causes of vertigo as a warning symptom is in the focus. The author draws attention to life-threatening conditions with acute onset in cases of the posterior scale ischemia and emphasizes the importance of the correct and early diagnosis. The author tries to clear up the nihilistic aspect in treating of stroke and stresses the necessity of thrombolysis and interventional radiological procedures which may be the only chance for the recovery of the patients. The pharmacological prevention of recurrent vascular events is also important and obligatory for the clinicians.]

Clinical Neuroscience

[3rd International Scientific Symposium on Parkinson’s Disease]

TAKÁTS Annamária

Clinical Neuroscience

[THE PERISYLVIAN EPILEPTIC NETWORK A unifying concept]

HALÁSZ Péter, KELEMEN Anna, CLEMENS Béla, SARACZ Judit, ROSDY Beáta, RÁSONYI György, SZŰCS Anna

[In this work the authors provide evidences for a unifying concept of the syndromes of benign focal childhood epilepsies, Landau-Kleffner syndrome, and electrical status epilepticus in sleep treating them as a spectrum of disorders with a common transient, age dependent, non lesional, genetically based epileptogenic abnormality, the nature of which is still not known. The electro-clinical features of these syndromes are congruent with the different degree involvement of the perisylvian cognitive network and with the involvement of the thalamo-cortical associative system of variable degree. These epilepsies are characterized by the abundance of regional epileptiform discharges in sharp contrast with the rare and in several cases lacking seizures. The nature and severity of interictal cognitive symptoms are closely related to localization within the network and amount of epileptic interictal discharges. Spike-wave discharges are attributed to an alternation of overexcitation (spikes) and overinhibition (waves). The recurrent overinhibition represented by the wave of the discharges may interfere with the continuous depolarization of the cells of a large population of neurons, which is a requirement of the overt seizures. The overinhibition also interfere with cognitive processes which are correlated with the continuous presence of the fast (gamma) activity, binding the required cortical areas. Hence the recurrent inhibition works against the existence of the binding fast frequency activity. This is the assumed reason for the co-existence of the relative lack of overt seizures and in the same time for the frequently observed epileptogenic cognitive deficit symptoms ("cognitive epilepsies"). The time course of these syndromes overlaps with important developmental milestones. The frequent epileptic discharges alters the evolution of the perisylvian network developing late after early childhood and is very vulnerable for any interference in this imprinting time for speech and other cognitive functions. This spectrum of disorders represents a type of age linked, mild to severe ‘epileptic encephalopathy’ limited to the perisylvian network, where the cognitive impairment is underlied by epileptic discharges interfering with cognitive development.]

All articles in the issue

Related contents

Clinical Neuroscience

[Regulatory mechanisms in focal cerebral ischemia. Perspectives in neuroprotective treatment]

NAGY Zoltán, SIMON László, BORI Zoltán

[Permanent or temporary disruption of cerebral blood flow rapidly depletes brain regions of their limited energy reserves (glycogen, glucose, oxygen, ATP) leading to an energy crisis. Tissue damage occurs due to the energy crisis. The central part of the damage, the ischaemic “core” region is surrounded by zones of the shell-like penumbra. Necrotic, as well as apoptotic cell death could be identified in the penumbra. Going away from the ischaemic core different neurochemical processes are occuring by space and time.“Immediate early response” genes (c-fos, fos-B, c-Jun, krox 20, 24) are activated, heatshock proteins (hsp 70, 72, HSF, HSE, HIF), cytokines (TNF-α, IL-1β), inflammatory factors (COX), adhesion and glial factors (ICAM-1, ELAM-1, P-selectin), vasoactive factors (IL -6, -10, PAF), reactive oxigen radicals and connected factors (O2, OH, NO, NOS, SOD) are produced within minutes and hours. Cell deaths, necrosis and apoptosis due to the activation of calpains, caspases and nucleases occur in days. In parallel, growth factors and plasticity proteins (BDNF, NGF, TGF-β, VEGF, PDGF, GAP-43) are activated as a basis of functional rehabilitation.]

Clinical Neuroscience

[NEW METHODS IN THE INVESTIGATION OF BRAIN HYPOXIA]

SZILÁGYI Géza, NAGY Zoltán

[The main challenge is the investigation of mechanism for apoptosis research and the drug development. Mitochondria have a key position in the production of reactive oxygen species and in the evolution of apoptosis. More possible pathway will be known with the apoptosis investigation. For development of neuroprotective molecules could give strategies the investigation of apoptosis. Exact knowledge of apoptosis provides possibility to screen new neuroprotective molecules. We elaborate a research assay, which could provide quantitative and qualitative data about the free radical production and the mitochondrial transmembrane potential using confocal microscope. So thus we could screen drug candidate, neuroprotective molecules.]

Hungarian Immunology

[Therapeutic treatment of rheumatoid arthritis by gene therapy-induced apoptosis]

JAMES M. Woods, VOLIN V. Michael

[Gene therapy was initially conceptualized as a treatment for individuals with genetic disorders, where defective genes would be replaced with functional ones. This concept was eventually broadened to include the use of gene therapy as a delivery mechanism for gene products effective in the treatment of diseases. The latter use of gene therapy, essentially as a drug delivery mechanism, was recognized to be particularly useful in the treatment of rheumatoid arthritis because it may have many advantages over traditional therapies. Two groups of target genes that are potentially useful for gene transfer include soluble inflammatory mediators that in theory could suppress the inflammatory process, and apoptotic mediators that may induce cell death, thereby suppressing the accumulation of inflammatory cells in the joint. To date the former group of target genes has received most of the attention, but it is the latter group of apoptosis-inducing targets that will be discussed in this review. We will focus our discussion on target genes that have shown success at inducing apoptosis in animal models of arthritis and will also include discussion of the apoptotic pathways that are altered in the attempts to reduce inflamed synovial tissue.]

Hungarian Immunology

[On the role of aging in etiology of autoimmunity]

SEMSEI Imre, ZEHER Margit, BAKÓ Gyula

[Several types of diseases, among others autoimmune illnesses, could be coupled with the general processes of aging. The two-edged sword of the immune defense is directed once against environmental attacks and on the other side against the self. However, one has to make a difference between normal (physiological) clearance and autoimmune diseases, although both sides of autoimmunity are influenced by the general processes of senescence. Aging of the thymus seems to be one of the key elements of the etiology of autoimmunity, although other cell types and their aging also play a substantial role in this process. The spontaneous genetic instability, the acquired genetic mutations due to aging and the age-related alterations of the information level of the body together may be important elements of the patomechanism of both the physiological autoimmunity and the autoimmune diseases. Nevertheless, physiological autoimmunity seems to be directed mostly by natural factors (such as aging and apoptosis) but primary autoimmune diseases may be caused by genetic instability that is enhanced by aging as well.]

Hungarian Immunology

[The role of nerve growth (NGF) factor in the immune and inflammatory events and in autoimmune thyroid diseases]

MOLNÁR Ildikó

[Nerve growth factor (NGF) is a neurotroph cytokine, and beside its effect on the central and peripheral nervous systems NGF plays an important role in the inflammatory and autoimmune processes. There are two types of NGF receptors, the high-affinity (TrkA) and the low-affinity (p75), which activations via signal transduction could lead to the inhibition or induction of apoptosis. Suppression of apoptosis could be induced by cytokines, hormones, antioxidans and increased intracellular Ca2+-levels. In the pathogenesis of many autoimmune diseases (systemic lupus erythematosus, 1-type diabetes mellitus, multiple sclerosis) could detect elevated serum levels of NGF associated with the disease activity. Our study demonstrated increased levels of NGF in autoimmune thyroid diseases (Graves’ disease, Hashimoto’s thyroiditis) in comparison with the controls. Decreased serum levels of NGF were found in Graves’ ophthalmopathy suggesting the role of apoptosis in the development of the eye symptoms. Orbital tissues are characterized with the high expression of TrkA receptors. NGF plays an important role in the pathomechanisms of neuro-immuno-hormonal diseases and its knowledge may be helpful in the diagnosis and therapy.]