RESUMEN

BACKGROUND: Erythropoietin (EPO) is neuroprotective in experimental models of stroke and subarachnoid haemorrhage (SAH) and possibly in patients with thromboembolic stroke. We studied the efficacy and safety of EPO in patients with SAH. METHODS: A larger scale clinical trial was planned but preliminarily terminated because of a lower than expected inclusion rate. However, 73 patients were randomised to treatment with EPO (500 IU/kg/day for three days) or placebo. The primary endpoint was Glasgow Outcome Score at six months. We further studied surrogate measures of secondary ischaemia, i.e. transcranial Doppler (TCD) flow velocity, symptomatic vasospasm, cerebral metabolism (microdialysis) and jugular venous oximetry, biochemical markers of brain damage (S-100beta and neuron specific enolase) and blood-brain barrier integrity. FINDINGS: The limited sample size precluded our primary hypotheses being verified and refuted. However, data from this study are important for any other study of SAH and as much raw data as possible are presented and can be included in future meta analyses. On admission the proportion of patients in a poor condition was higher in the EPO group compared with the placebo group but the difference was statistically insignificant. In the EPO-treated patients the CSF concentration of EPO increased 600-fold. Except for a higher extracelullar concentration of glycerol in the EPO group probably caused by the poorer clinical condition of these patients, there were no statistically significant group differences in the primary or secondary outcome measures. EPO was well tolerated. CONCLUSIONS: Beneficial effects of EPO in patients with SAH cannot be excluded or concluded on the basis of this study and larger scale trials are warranted.

Asunto(s)

Eritropoyetina/uso terapéutico , Hematínicos/uso terapéutico , Aneurisma Intracraneal/complicaciones , Fármacos Neuroprotectores/uso terapéutico , Hemorragia Subaracnoidea/tratamiento farmacológico , Adulto , Anciano , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Encéfalo/efectos de los fármacos , Daño Encefálico Crónico , Método Doble Ciego , Epoetina alfa , Eritropoyetina/líquido cefalorraquídeo , Femenino , Estudios de Seguimiento , Escala de Consecuencias de Glasgow , Mortalidad Hospitalaria , Humanos , Aneurisma Intracraneal/mortalidad , Aneurisma Intracraneal/cirugía , Imagen por Resonancia Magnética , Masculino , Microdiálisis , Microcirugia , Persona de Mediana Edad , Consumo de Oxígeno/efectos de los fármacos , Premedicación , Proteínas Recombinantes , Hemorragia Subaracnoidea/diagnóstico , Tomografía Computarizada por Rayos X , Ultrasonografía Doppler Transcraneal

RESUMEN

OBJECTIVE: Apolipoprotein E-epsilon4 (APOE-epsilon4) is a potential risk factor for cerebral vascular disease. The aim of the present study was to examine the relative importance of APOE-epsilon4 and other relevant risk factors for the extent of cerebral white matter hyperintensity (WMH) in a community-based sample of elderly subjects. MATERIALS AND METHODS: From a cohort of 976 subjects born in 1914, APOE genotype was determined and MRI examinations were carried out in 75 subjects. WMH were rated using a standard semi-quantitative method. ANOVA and regression analyses were conducted to explore the relative importance of the potential risk factors. RESULTS: APOE genotype and antihypertensive treatment were significantly associated with severity of total WMH load (P < 0.05). CONCLUSIONS: The study confirmed the association between APOE-epsilon4 and WMH. Pharmaceutical treatment for arterial hypertension was also associated with the total burden of WMH in this study.

Asunto(s)

Antihipertensivos/efectos adversos , Apolipoproteína E4/genética , Encéfalo/patología , Anciano de 80 o más Años , Consumo de Bebidas Alcohólicas/efectos adversos , Estudios de Cohortes , Femenino , Genotipo , Humanos , Imagen por Resonancia Magnética , Masculino , Factores de Riesgo

RESUMEN

OBJECTIVE: A polymorphism in the promoter region of the NPY gene at position -399 C > T was recently reported to be associated with schizophrenia in a Japanese population and with treatment refractory unipolar depression in a Swedish population. The objective of this study was to investigate potential associations between the polymorphism and three psychiatric disorders in a Danish population. METHOD: We investigated the occurrence of the polymorphism in patients with schizophrenia (n = 291), unipolar depression (n = 256) and panic disorder (n = 142) compared with controls (n = 716). RESULTS: We detected the polymorphism -399 C > T at a frequency of 48% in controls. No significant differences were found between genotype or allele frequencies in controls vs. the patient groups. CONCLUSION: The lack of association between the -399 C > T polymorphism and schizophrenia, unipolar depression or panic disorder, respectively, suggests that the polymorphism is not involved in the etiology of these disorders in the Danish population.

Asunto(s)

Alelos , Trastorno Depresivo/etnología , Trastorno Depresivo/genética , Neuropéptido Y/genética , Trastorno de Pánico/etnología , Trastorno de Pánico/genética , Polimorfismo Genético/genética , Esquizofrenia/etnología , Esquizofrenia/genética , Adulto , Anciano , Anciano de 80 o más Años , Cartilla de ADN/genética , Dinamarca/epidemiología , Trastorno Depresivo/epidemiología , Femenino , Frecuencia de los Genes/genética , Genotipo , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Trastorno de Pánico/epidemiología , Reacción en Cadena de la Polimerasa , Prevalencia , Esquizofrenia/epidemiología

RESUMEN

As the understanding of the autoimmune inflammatory response in multiple sclerosis (MS) expands, polymorphic genes involved in this process become possible candidates that may determine the severity of disease. Therefore, three candidate genes DRB1*1501, CCR5 and apolipoprotein E (APOE) were examined in a population-based patient sample (n = 70) to assess an association between disease progression measured by clinical disability and MRI parameters. The total lesion area (TLA) on T2-weighted images was measured with a semi-automated threshold technique. Patients with the CCR5delta32 allele showed a non-significant trend towards a smaller lesion burden (TLA/years duration), but were not associated to a milder EDSS/years duration. Our data support previous assumptions of a modulation of severity in MS by the CCR5delta32 genotype, which may convey less inflammation and tissue destruction. Carriers of the DRB1*1501 and APOE-epsilon4 allels did not reveal more severe disease progression, neither by the EDSS/years of duration nor by the TLA/years duration. This study was performed on a population-based sample in a genetically homogeneous Danish population but, due to the limited number of patients examined, weak associations between candidate genes and disease variables cannot be excluded.

Asunto(s)

Marcadores Genéticos , Esclerosis Múltiple/genética , Esclerosis Múltiple/patología , Índice de Severidad de la Enfermedad , Adulto , Apolipoproteínas E/genética , Dinamarca , Eliminación de Gen , Genotipo , Antígenos HLA-DR/genética , Cadenas HLA-DRB1 , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Receptores CCR5/genética , Población Blanca/genética

RESUMEN

The aim of this study was to examine the impact of the apolipoprotein E (APOE) epsilon4 allele on semiquantitative regional cerebral blood flow (rCBF) in Alzheimer's disease. Single photon emission computed tomography technetium (SPECT) with (99m)Tc d,l-hexamethyl propylenamine oxine was used to determine rCBF in 41 consecutive patients (18 males/23 females) with probable Alzheimer's disease according to the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria (mean age 71.0 years; range 54-85). The mean Mini-Mental State Examination (MMSE) score was 20.4 (range 10-30). After normalization of CBF to mean blood flow in the cerebellum, values for rCBF in several cortical regions of interest, side-to-side asymmetry indices, and anterior-posterior ratios were calculated. Determination of the APOE genotype from blood samples was performed using restriction enzyme polymerase chain reaction technique. Multivariate regression analyses and the Wilcoxon rank-sum test for unpaired data (Mann-Whitney) were used for statistical analysis. The patients comprised 27APOE epsilon4-positive and 14APOE epsilon4-negative individuals. Five patients were APOE epsilon4 homozygotes. APOE epsilon4-positive patients had significantly reduced rCBF in the right frontal and left occipital lobes. On nonparametric analysis, the most prominent differences between epsilon4-negative and epsilon4-positive patients were demonstrated in subregions representing the frontal association cortex (Mann-Whitney, P < .01). Age-stratified analysis suggested that these findings could be demonstrated predominantly in the elderly patients. The results of this study suggest that the APOE genotype in itself may have an impact on the pattern of rCBF deficits in Alzheimer's disease. The more pronounced reduction of rCBF in frontal association cortex observed in elderly APOE epsilon4-positive patients might predict clinical progression.

Asunto(s)

Enfermedad de Alzheimer/genética , Apolipoproteínas E/genética , Encéfalo/irrigación sanguínea , Circulación Cerebrovascular/genética , Dominancia Cerebral/genética , Tomografía Computarizada de Emisión de Fotón Único , Factores de Edad , Anciano , Anciano de 80 o más Años , Alelos , Enfermedad de Alzheimer/fisiopatología , Apolipoproteína E4 , Encéfalo/diagnóstico por imagen , Estudios de Casos y Controles , Femenino , Lóbulo Frontal/irrigación sanguínea , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Lóbulo Occipital/irrigación sanguínea , Pronóstico

RESUMEN

Previously, inhalation exposure to different types of white spirit (i.e. complex mixtures of aliphatic, aromatic, alkyl aromatic, and naphthenic hydrocarbons) has been shown to induce neurochemical effects in rat brains. Especially, the serotonergic system was involved at the global, regional, and subcellular levels. This study investigates the effects of two types of white spirit on 5-hydroxytryptamine (5-HT) transporters (5-HTT), 5-HT(2A) and 5-HT(4) receptor expression in forebrain, and on neural cell adhesion molecule (NCAM) and 25-kDa synaptosomal associated protein (SNAP-25) concentrations when applied as indices for synaptic remodeling in forebrain, hippocampus, and entorhinal cortex. Male Wistar rats were exposed to 0, 400, or 800 ppm of aromatic (20 vol.% aromatic hydrocarbons) or dearomatized white spirit (catalytically hydrogenated white spirit) in the inhaled air for 6 h/day, 7 days/week for 3 weeks. The 5-HTT B(max) and K(d) were not affected. Both types of white spirit at 800 ppm decreased B(max) for the 5-HT(2A) receptor. The aromatic type decreased the K(d) of the 5-HT(2A) and 5-HT(4) receptors at 800 ppm. Aromatic white spirit did not affect NCAM or SNAP-25 concentrations or NCAM/SNAP-25 ratio in forebrain, whereas NCAM increased in hippocampus and the NCAM/SNAP-25 ratio decreased in entorhinal cortex. Dearomatized white spirit did not affect NCAM, SNAP-25, or NCAM/SNAP-25 ratio in any brain region. The affected 5-HT receptor expression and synaptic plasticity marker proteins indicate that inhalation exposure to high concentrations of white spirit may be neurotoxic to rats, especially the aromatic white spirit type.

Asunto(s)

Química Encefálica/efectos de los fármacos , Hidrocarburos/toxicidad , Proteínas de Transporte de Membrana , Receptores de Serotonina/efectos de los fármacos , Solventes/toxicidad , Administración por Inhalación , Animales , Proteínas Portadoras/análisis , Corteza Entorrinal/química , Hipocampo/química , Masculino , Glicoproteínas de Membrana/análisis , Proteínas de la Membrana/análisis , Proteínas del Tejido Nervioso/análisis , Moléculas de Adhesión de Célula Nerviosa/análisis , Ratas , Receptor de Serotonina 5-HT2A , Receptores de Serotonina/metabolismo , Receptores de Serotonina 5-HT4 , Proteínas de Transporte de Serotonina en la Membrana Plasmática , Proteína 25 Asociada a Sinaptosomas

RESUMEN

The purpose of this study was to investigate the relation between APOE genotype and Multiple Sclerosis (MS) in a genetically homogeneous population. We examined 240 patients consulting the MS-clinic during a period of 3 years (1996 - 1999). The mean age of the patients was 41.7 years (range 19 - 80 Y, SD 10.0 Y). As a measure of the progression rate (PR) the last registered Expanded Disability Status Scale (EDSS) score was divided by the time span (years) from disease onset until the latest assessment. The APOE genotype was determined from saliva and/or blood samples using PCR-techniques. The prevalence of different APOE genotypes was compared with the allele-distribution in a population of 361 persons from a Danish cross-sectional population study. The frequency of APOE-epsilon 4/epsilon 4 homozygotes was significantly higher in the MS-group as compared to controls (P<0.05, odds ratio: 2.3), whereas the frequency distribution of other genotypes did not differ significantly. The rate of progression was significantly faster in the APOE-epsilon 4/epsilon 4 homozygotes compared to other genotypes in the MS group (P<0.05). This study suggests that the APOE-epsilon 4/epsilon 4 homozygotes have an increased risk of developing MS. MS patients with the APOE-epsilon 4/epsilon 4 allele may also have an increased rate of disease progression. Multiple Sclerosis (2000) 6 226 - 230

Asunto(s)

Apolipoproteínas E/genética , Predisposición Genética a la Enfermedad , Esclerosis Múltiple/genética , Esclerosis Múltiple/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Apolipoproteína E4 , Estudios Transversales , Evaluación de la Discapacidad , Progresión de la Enfermedad , Femenino , Frecuencia de los Genes , Genotipo , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo

RESUMEN

Cultured mouse cerebellar granule cells differ from their rat counterparts in that they survive well when grown in non-depolarising medium (5 mM K(+)). However, when chronically stimulated by added glutamate agonists, including (RS)alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), rat cerebellar granule cells also survive well in non-depolarising medium. We hypothesised that the relatively good survival of mouse cerebellar granule cells in the absence of added glutamate agonists might reflect AMPA receptors resistant to desensitisation. These receptors might be stimulated by endogenous glutamate. We tested this hypothesis by comparing cultured mouse and rat cerebellar granule cells grown in depolarising (25 mM K(+)) and non-depolarising (5 mM K(+)) medium. We studied the AMPA-induced increase in intracellular Ca(2+) concentration ([Ca(2+)](i)), using the fluorescent Ca(2+) chelator, Fluo-3, and the relative concentrations of mRNAs for the four AMPA receptor subunits, GluR1-4. GluR1-4 mRNAs were measured by restriction enzyme analysis of a PCR product containing cDNA with a composition proportional to the four subunit mRNAs. We found that the [Ca(2+)](i)-response to AMPA receptor activation in cultured cerebellar granule cells is determined mainly by the desensitisation properties of the AMPA receptors rather than by their ion permeability. We also found that mouse cerebellar granule cells express AMPA receptors which are more resistant to desensitisation than the corresponding rat AMPA receptors. Thus, relatively slow AMPA receptor desensitisation kinetics may contribute to the survival of mouse cerebellar granule cells in non-depolarising medium.

Asunto(s)

Calcio/metabolismo , Cerebelo/citología , Neuronas/química , Neuronas/metabolismo , Receptores AMPA/genética , Animales , Transporte Biológico/efectos de los fármacos , Transporte Biológico/fisiología , Bloqueadores de los Canales de Calcio/farmacología , División Celular/efectos de los fármacos , Células Cultivadas , Maleato de Dizocilpina/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Regulación del Desarrollo de la Expresión Génica , Ratones , Neuronas/citología , Nifedipino/farmacología , Potasio/farmacología , ARN Mensajero/análisis , Ratas , Receptores AMPA/metabolismo , Sodio/metabolismo , Tetrodotoxina/farmacología

RESUMEN

BACKGROUND: The epsilon 4 allele of apolipoprotein E (APOE) as well as affective disorder have been found to be associated with Alzheimer's disease, but it is unclear whether cognitive impairment in affective disorder or subtypes of affective disorder is mediated by the epsilon 4 allele of APOE. METHODS: The genotype of APOE was analyzed in 106 unipolar patients, 21 bipolar patients, and 46 controls and correlated with cognitive function in the euthymic phase as measured by the Mini-Mental State Examination, the Cambridge Cognitive Examination, the Mattis Dementia Rating Scale, the Gottfries-Bråne-Steen Dementia Rating Scale, and the Global Deterioration Scale. RESULTS: The frequency of APOE-epsilon 4 allele was approximately the same in unipolar patients (.189) and in bipolar patients (.167). Although patients showed more cognitive impairment than controls, no significant overall difference was found between the frequency of APOE-epsilon 4 allele in patients (.185) and controls (.131). In fact, the frequency of APOE-epsilon 4 allele did not correlate with cognitive impairment. It was not possible to identify subgroups of patients with an increased frequency of APOE-epsilon 4 allele, as no association was found with gender, age at onset, the number of affective episodes, the presence of psychotic features, or the prevalence of familial affective disorder. CONCLUSIONS: It seems that cognitive impairment in affective disorder can be attributed to pathways other than the APOE genotype.

Asunto(s)

Apolipoproteínas E/genética , Trastornos del Conocimiento/genética , Trastornos del Humor/genética , Adulto , Apolipoproteína E4 , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Trastornos del Conocimiento/complicaciones , Estudios de Cohortes , Dinamarca , Femenino , Dosificación de Gen , Humanos , Funciones de Verosimilitud , Masculino , Trastornos del Humor/complicaciones

RESUMEN

A three year-old girl with Leber's amaurosis was found to fulfil the criteria for autism, as will as being mentally retarded. Despite her blindness she displayed unusually by early motor development and was able to move around in her surroundings without difficulty. This case suggests that this ability was due to her relevant use of a minor visual remnant and, as is often seen in blindness, a capability of reflecting the surroundings--a "bat sense". The pervasive development a disorder influenced her abilities more strongly than her sensory handicap.

Asunto(s)

Trastorno Autístico/complicaciones , Ceguera/complicaciones , Discapacidad Intelectual/complicaciones , Trastorno Autístico/diagnóstico , Ceguera/diagnóstico , Preescolar , Comorbilidad , Femenino , Humanos , Lactante , Discapacidad Intelectual/diagnóstico , Pruebas Psicológicas

Asunto(s)

Depresión/tratamiento farmacológico , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Adolescente , Factores de Edad , Antidepresivos/uso terapéutico , Niño , Preescolar , Humanos

RESUMEN

This article describes the Danish part of a multinational epidemiological point-prevalence study concerning child psychiatric in-patient treatment, which aims to describe different kinds of treatment methods used in child psychiatric in-patient care. The study includes all 10 child psychiatric in-patient units in Denmark. Data on psychiatric treatment modalities were collected by means of a questionnaire in spring 1990 on 192 children, which included all of the actual in-patients (100%). Primary caretaking was the main treatment method (100%), individual psychotherapy was offered to one third, as was family therapy. Eight percent were medicated, 6% with psychoactive drugs. The study showed that medication in child psychiatric in-patient care was rare, and was never the only treatment method. A range of psychotherapeutic methods were used.

Asunto(s)

Psiquiatría Infantil , Niño Hospitalizado , Psicoterapia/métodos , Adolescente , Niño , Preescolar , Dinamarca , Femenino , Humanos , Masculino , Pautas de la Práctica en Medicina , Encuestas y Cuestionarios

Asunto(s)

Enfermedad de Alzheimer/etiología , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/fisiopatología , Enfermedad de Alzheimer/terapia , Humanos , Modelos Neurológicos

RESUMEN

Insoluble aggregates of the amyloid beta-peptide (A beta) is a major constituent of senile plaques found in brains of Alzheimer disease (AD) patients. The detrimental effects of aggregated A beta is associated with an increased intracellular Ca2+ concentration ([Ca2+]i). We examined the effects of A beta(25-35) on [Ca2+]i and intracellular H+ concentration ([H+]i) in single hippocampal neurons by real time fluorescence imaging using the Ca(2+)- and H(+)-specific ratio dyes, indo-1 and SNARF-1. Incubation of these cultures with A beta(25-35) for 3-12 days in vitro increased [Ca2+]i and [H+]i in large, NMDA-responsive neurons.

Asunto(s)

Péptidos beta-Amiloides/farmacología , Calcio/metabolismo , Hipocampo/metabolismo , Neuronas/metabolismo , Fragmentos de Péptidos/farmacología , Animales , Animales Recién Nacidos , Astrocitos/citología , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Benzopiranos , Supervivencia Celular , Células Cultivadas , Colorantes Fluorescentes , Proteína Ácida Fibrilar de la Glía/análisis , Hipocampo/citología , Concentración de Iones de Hidrógeno , Indoles , Cinética , Microscopía Fluorescente , Naftoles , Neuronas/citología , Neuronas/efectos de los fármacos , Ratas , Rodaminas , Factores de Tiempo

RESUMEN

The purpose of this study was to explore whether bilateral frontal cortex contusion in rats would demonstrate changes relevant for understanding the pathology of frontal lobe injury in humans. Rats were allowed to survive for 3, 7, or 18 days postinjury (dpi). In the contused rats, albumin was trapped in frontal cortices, as well as in other brain areas, showing that neurons were exposed to plasma components. In the sham-operated rats, which had only craniotomy but no penetration of dura, the level of trapped albumin was also increased compared to intact controls, suggesting a partial lesion-like condition. Choline acetyltransferase activity was severely decreased in the frontal cortices of contused rats, compared to the sham-operated controls. The decrease was most pronounced at 3 dpi and less pronounced 18 dpi, suggesting that after the initial damage, regeneration of the cholinergic terminals occurred. The concentration of the mature presynaptic membrane protein D3(SNAP-25) was also decreased in the frontal cortices of contused rats at 3 and 7 dpi, whereas it was normalized at 18 dpi. Previously, we have evaluated changes in the rate of synaptic remodeling in brain injury by calculating the ratio of the neural cell adhesion molecule (NCAM) to D3(SNAP-25). The NCAM/D3(SNAP-25) ratio at 3 dpi was elevated by more than 60% in the frontal cortices of contused rats, suggesting a high initial rate of synaptic remodeling. The ratios were smaller at 7 and 18 dpi, suggesting that after the initial burst, the rate of remodeling leveled off. In contrast, astrocyte activation was less pronounced at 3 dpi than at 7 and 18 dpi, as measured by the levels of glial fibrillary acidic protein and glutamine synthetase immunoactivities. The immunoreactivity of glutamine synthetase more than doubled in the contused brains but its enzymatic activity increased less than 50%, suggesting that many enzymatic centers had been inactivated by free radicals. Calculated as the difference between the relative immunoreactivity and the relative enzymatic activity the "lost glutamine synthetase activity" increased continuously in frontal cortex and striatum from 3 to 18 dpi, indicating the production of free radicals long after the initial contusion event. In conclusion, following frontal cortical contusions the early synaptic damage was partly compensated by synaptic remodeling. We suggest that the continuous production of free radicals may have contributed to the declining remodeling rate and impair functional recovery.

Asunto(s)

Lesiones Encefálicas/fisiopatología , Fibras Colinérgicas/fisiología , Contusiones/fisiopatología , Lóbulo Frontal/lesiones , Proteínas de la Membrana , Regeneración Nerviosa , Especies Reactivas de Oxígeno/metabolismo , Sinapsis/fisiología , Animales , Astrocitos/metabolismo , Astrocitos/patología , Biomarcadores , Edema Encefálico/etiología , Edema Encefálico/metabolismo , Edema Encefálico/fisiopatología , Lesiones Encefálicas/complicaciones , Lesiones Encefálicas/metabolismo , Colina O-Acetiltransferasa/análisis , Fibras Colinérgicas/metabolismo , Contusiones/complicaciones , Contusiones/metabolismo , Radicales Libres , Lóbulo Frontal/metabolismo , Lóbulo Frontal/fisiopatología , Proteína Ácida Fibrilar de la Glía/análisis , Glutamato-Amoníaco Ligasa/análisis , Masculino , Proteínas del Tejido Nervioso/análisis , Moléculas de Adhesión de Célula Nerviosa/análisis , Ratas , Ratas Sprague-Dawley , Proteína 25 Asociada a Sinaptosomas , Factores de Tiempo

RESUMEN

We studied the effects of chronic K(+)-induced membrane depolarization and treatment with N-methyl-D-aspartate (NMDA) on cerebellar granule cells (CGCs) from weaver mutant mice and non-weaver litter-mates. The weaver mutation is a Gly-to-Ser substitution in a conserved region of the Girk2 G protein-coupled inward rectifying potassium channel [Patil N., Cox D. R., Bhat D., Faham M., Myers R. M. and Peterson A. S. (1995) Nature Genet. 11, 126-129] which induces early death of CGCs. The biochemical differentiation of CGCs was estimated as the rate of 2-deoxy-D-glucose accumulation and the expression of neural cell adhesion molecule (NCAM). High (25 mM) K+ ion concentration or treatment with NMDA greatly promoted the biochemical differentiation of both weaver mutant and non-weaver litter-mate mouse CGCs. In contrast to the marked effect on biochemical differentiation in both weaver and non-weaver mice CGSs, chronic high K+ treatment only had limited effect on survival. The survival of weaver mutant mouse CGCs in medium containing 5 mM K+ ions was very low, only 20% of the plated cells surviving at 7 days after plating, as opposed to the 50% for non-weaver CGCs. Chronic high K+ treatment improved the relative survival of weaver mutant mouse CGCs 1.6 2.2-fold and that of non-weaver CGCs 1.2-1.4-fold; the same number of CGCs (about 20% of the plated cells) were rescued by high K+ in both types of culture. The findings indicate that, in culture weaver mutant mouse, CGCs have a normal response to membrane depolarization and that the normal function of the Girk2 potassium channel is not critical for the survival of differentiated CGCs.

Asunto(s)

Cerebelo/fisiología , Ratones Mutantes Neurológicos/fisiología , Animales , Diferenciación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Senescencia Celular , Cerebelo/citología , Cerebelo/metabolismo , Desoxiglucosa/metabolismo , Electrofisiología , Ratones , N-Metilaspartato/farmacología , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Potasio/farmacología , Valores de Referencia , Factores de Tiempo

RESUMEN

We have previously reported that, unlike their rat counterparts, the survival of mouse cerebellar granule cells is independent of chronic stimulation whether owing to elevated K(+)-induced depolarization or NMDA (N-methyl-D-aspartate) receptor activation. One explanation could be that during the critical period mouse granule cells are very sensitive to NMDA receptor stimulation by endogenous glutamate released in the cultures. If so, this might be reflected by an increased expression of NMDA receptors or an increased response to their activation. We tested this hypothesis by measuring (a) the concentration of mRNA for the obligatory NMDA receptor subunit, NMDAR1, and (b) the glutamate/NMDA stimulated increase in cytosolic Ca(2+)-ion concentration in cultures at physiological or elevated K(+)-ion concentration. The expression of NMDAR1 mRNA was measured by competitive PCR of reversely transcribed mRNA and was normalized to that of the constitutively expressed H3.3 histone mRNA. The glutamate and NMDA stimulated increase in cytosolic Ca(2+)-ion concentration was measured using the fluorescent Ca(2+)-chelator Fluo3. In contrast to the hypothesis, we found NMDAR1 mRNA expression to be lower in mouse than in rat granule cells cultured for 4 days at physiological K(+)-ion concentration. However, the NMDA stimulated increase in cytosolic Ca(2+)-ion concentration did not differ in 4-day rat and mouse cultures. Although the glutamate-stimulated increase in cytosolic Ca(2+)-ion concentration in 2-day cultures was higher in mouse granule cells than in rat granule cells, the developmental profile of the glutamate-stimulated increase in cytosolic Ca(2+)-ion concentration was the same in both cases. In conclusion, we found no obvious evidence for increased NMDA receptor activity in mouse cerebellar granule cells cultured at physiological K(+)-ion concentration.

Asunto(s)

Calcio/metabolismo , Cerebelo/metabolismo , Neuronas/metabolismo , ARN Mensajero/biosíntesis , Receptores de Glutamato/fisiología , Receptores de N-Metil-D-Aspartato/genética , Compuestos de Anilina , Animales , Supervivencia Celular/fisiología , Células Cultivadas , Cerebelo/citología , Citosol/metabolismo , Colorantes Fluorescentes , Ácido Glutámico/fisiología , Modelos Lineales , Ratones , Neuronas/ultraestructura , Ratas , Xantenos

RESUMEN

Kindling of the olfactory bulb using a novel fast protocol (within 24 h) was studied in rats. In target brain regions, the effects of kindling were measured on the concentration of glial fibrillary acidic protein (GFAP) by dot-blot and on the concentrations of neural cell adhesion molecule (NCAM) and the 25 kDa synaptosomal associated protein of the D3 immunoprecipitate (D3(SNAP-25)) by crossed immunoelectrophoresis. Bilateral increases in the levels of GFAP, indicating activation of astrocytes, were detected in primary olfactory cortical projection areas, including the piriform cortex, and also in the basolateral amygdala and dentate gyrus, suggesting that these regions may be functionally altered during the kindling process. In the piriform cortex and dentate gyrus increased NCAM/D3(SNAP-25) ratios found ipsilaterally at seven days after kindling probably reflect an elevated rate of synaptic remodelling. At this time, however, an overall pattern of ipsilateral decreases in the synaptic marker proteins NCAM and D3(SNAP-25) indicated that this remodelling occurred on a background of synaptic degeneration. These results confirm previous studies showing that kindling is associated with synaptic remodelling and neuronal degeneration in the hippocampal formation and extends the area of plasticity to include the piriform cortex which is believed to be central to the kindling process.

Asunto(s)

Encéfalo/fisiología , Excitación Neurológica , Proteínas de la Membrana , Bulbo Olfatorio/fisiología , Sinapsis/fisiología , Animales , Astrocitos/fisiología , Biomarcadores , Proteína Ácida Fibrilar de la Glía/análisis , Proteína Ácida Fibrilar de la Glía/metabolismo , Inmunoelectroforesis Bidimensional , Masculino , Degeneración Nerviosa , Proteínas del Tejido Nervioso/análisis , Proteínas del Tejido Nervioso/metabolismo , Moléculas de Adhesión de Célula Nerviosa/análisis , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Especificidad de Órganos , Ratas , Ratas Wistar , Proteína 25 Asociada a Sinaptosomas , Sinaptosomas/fisiología

RESUMEN

The rat synaptosomal membrane antigen D3, which has been studied for more than 20 years since its first demonstration as a brain-specific protein, was shown to bind monoclonal antibodies to SNAP-25, a presynaptic plasma membrane-associated protein. In addition to SNAP-25, anti-D3 antiserum also precipitated two polypeptides of 34-36 kDa and 14-16 kDa. This suggests that anti-D3 binds all three of the 20S synaptic vesicle fusion particle components, i.e. SNAP-25, syntaxin, and vesicle-associated membrane protein (VAMP)/synaptobrevin. However, the botulinum toxins C and D, which are endoproteases selective for syntaxin and VAMP/synptobrevin, respectively, were unable to remove the D3 immunoreactivity from synaptosomal membranes. Therefore, it is concluded that D3 immunoreactivity is directed only against SNAP-25.

Asunto(s)

Proteínas de la Membrana , Proteínas del Tejido Nervioso/análisis , Proteínas del Tejido Nervioso/química , Neuropéptidos/química , Secuencia de Aminoácidos , Análisis de Varianza , Animales , Detergentes , Datos de Secuencia Molecular , Octoxinol , Ratas , Solubilidad , Proteína 25 Asociada a Sinaptosomas

RESUMEN

The neural cell adhesion molecule (NCAM) participates in adhesion and neuritic outgrowth during nervous system development. In the adult brain, NCAM is considered to be involved in neuronal sprouting and synaptic remodeling. The NCAM concentration of brain tissue has proved to be a useful marker of these processes, especially when viewed in comparison with the concentration of a marker of mature synapses, e.g. D3-protein (SNAP-25) or synaptophysin. The present review focusses on studies of adult brain in which NCAM concentration estimates and NCAM/D3 ratios have been used to evaluate the rate of synaptic remodeling in brain damage and degenerative diseases.

Asunto(s)

Química Encefálica/fisiología , Moléculas de Adhesión Celular Neuronal/análisis , Proteínas del Tejido Nervioso/análisis , Sinapsis/química , Animales , Biomarcadores/química , Daño Encefálico Crónico/metabolismo , Humanos , Degeneración Nerviosa/fisiología