RESUMO
"Heart appearance" on magnetic resonance imaging (MRI) is a unique presentation of bilateral medial medullary infarction. In contrast, "heart appearance" infarction of the pons has rarely been featured in the medical literature. In this paper, we present a case of "heart appearance" infarction of the pons with its MRI and magnetic resonance angiography (MRA) findings. The patient was an 87-year-old male who manifested with weakness in the four extremities. Later, bulbar palsy and tetraplegia became apparent, and he eventually was trapped in locked-in syndrome. Brain MRI disclosed a "heart appearance" lesion in the pons, which was high on diffusion-weighted image MRI and low on apparent diffusion coefficient map MRI. Brain MRA demonstrated that the basilar artery remained intact. A diagnosis of fresh, bilateral pontine infarction with a "heart appearance" was made. After the treatment he was transferred to another hospital for long-term care. This case suggests that bilateral ischemic involvement of the pons is possible even in the context of an intact basilar artery.
RESUMO
We describe a 17-year-old girl with Kleine-Levin syndrome (KLS), in which gabapentin was effective for the prevention of attacks. (99)mTc-ECD SPECT revealed hyperperfusion of the thalamus and nucleus accumbens presenting in the symptomatic period, suggesting epilepsy-like neuronal discharge from these structures. Treatment for KLS has not been established, although lithium has been used in limited cases with insignificant efficacy. Here, we report a case of recurrent hypersomnia in which gabapentin was effective for the prevention of attacks. We speculate that the recurrent hypersomnia and behaviour disturbance are related to epilepsy-like neuronal discharge from the thalamus due to dysfunction in GABAnergic receptors.
Assuntos
Aminas/uso terapêutico , Anticonvulsivantes/uso terapêutico , Ácidos Cicloexanocarboxílicos/uso terapêutico , Síndrome de Kleine-Levin/tratamento farmacológico , Ácido gama-Aminobutírico/uso terapêutico , Adolescente , Eletroencefalografia , Feminino , Gabapentina , Humanos , Síndrome de Kleine-Levin/diagnóstico , Síndrome de Kleine-Levin/fisiopatologia , Imageamento por Ressonância Magnética , Receptores de GABA-A/fisiologia , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Recent studies have revealed that the adult mammalian brain has the capacity to regenerate some neurons after various insults. However, the precise mechanism of insult-induced neurogenesis has not been demonstrated. In the normal brain, GFAP-expressing cells in the subventricular zone (SVZ) of the lateral ventricles include a neurogenic cell population that gives rise to olfactory bulb neurons only. Herein, we report evidence that, after a stroke, these cells are capable of producing new neurons outside the olfactory bulbs. SVZ GFAP-expressing cells labeled by a cell-type-specific viral infection method were found to generate neuroblasts that migrated toward the injured striatum after middle cerebral artery occlusion. These neuroblasts in the striatum formed elongated chain-like cell aggregates similar to those in the normal SVZ, and these chains were observed to be closely associated with thin astrocytic processes and blood vessels. Finally, long-term tracing of the green fluorescent-labeled cells with a Cre-loxP system revealed that the SVZ-derived neuroblasts differentiated into mature neurons in the striatum, in which they expressed neuronal-specific nuclear protein and formed synapses with neighboring striatal cells. These results highlight the role of the SVZ in neuronal regeneration after a stroke and its potential as an important therapeutic target for various neurological disorders.
Assuntos
Diferenciação Celular/fisiologia , Movimento Celular/fisiologia , Corpo Estriado/patologia , Ventrículos Laterais/citologia , Neurônios/fisiologia , Células-Tronco/fisiologia , Acidente Vascular Cerebral/metabolismo , Animais , Animais Geneticamente Modificados , Contagem de Células/métodos , Corpo Estriado/metabolismo , Corpo Estriado/fisiopatologia , Modelos Animais de Doenças , Proteínas do Domínio Duplacortina , Imunofluorescência/métodos , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Infarto da Artéria Cerebral Média , Camundongos , Camundongos Endogâmicos ICR , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/ultraestrutura , Neuropeptídeos/metabolismo , Acidente Vascular Cerebral/fisiopatologia , Fatores de TempoRESUMO
In the subventricular zone (SVZ) of the adult mammalian brain, neural stem cells continually produce transit-amplifying precursors, which generate neuroblasts migrating into the olfactory bulb. Previous studies have suggested that SVZ cells also have the capacity to generate some striatal neurons after cerebral ischemia. The infusion of epidermal growth factor (EGF) has been demonstrated to increase the number of these regenerated neurons. However, which cell types in the SVZ are stimulated to proliferate or differentiate after EGF infusion remains unknown. In this paper, we demonstrated that cerebral ischemia results in an increase in the number of EGF receptor (EGFR)-positive transit-amplifying cells in the SVZ. EGF infusion into the ischemic brain caused the number of transit-amplifying cells to increase and the number of neuroblasts to decrease. On the other hand, after an interval of 6 days after the discontinuation of EGF infusion, a significant increase in the number of neuroblasts was found, both in the striatum and the SVZ. These results suggest that the replacement of neurons in injured striatum can be enhanced by an EGF-induced expansion of transit-amplifying cells in the SVZ.
Assuntos
Isquemia Encefálica/patologia , Ventrículos Cerebrais/patologia , Corpo Estriado/efeitos dos fármacos , Fator de Crescimento Epidérmico/farmacologia , Neurônios/patologia , Animais , Astrócitos/patologia , Movimento Celular , Corpo Estriado/irrigação sanguínea , Corpo Estriado/patologia , Fator de Crescimento Epidérmico/administração & dosagem , Receptores ErbB/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos ICR , Proteínas Recombinantes/farmacologiaRESUMO
In the subventricular zone of the adult mammalian forebrain, neural stem cells (NSCs) reside and proliferate to generate young neurons. We screened factors that promoted the proliferation of NSCs in vitro by a recently developed proteomics technique, the ProteinChip system. In this screen, we identified a soluble carbohydrate-binding protein, Galectin-1, as a candidate. We show herein that Galectin-1 is expressed in a subset of slowly dividing subventricular zone astrocytes, which includes the NSCs. Based on results from intraventricular infusion experiments and phenotypic analyses of knockout mice, we demonstrate that Galectin-1 is an endogenous factor that promotes the proliferation of NSCs in the adult brain.
Assuntos
Carboidratos , Proliferação de Células , Galectina 1/metabolismo , Neurônios/fisiologia , Células-Tronco/fisiologia , Animais , Astrócitos/citologia , Astrócitos/fisiologia , Células Cultivadas , Galectina 1/genética , Humanos , Masculino , Camundongos , Camundongos Knockout , Neurônios/citologia , Fenótipo , Prosencéfalo/citologia , Prosencéfalo/metabolismo , Análise Serial de Proteínas , Ligação Proteica , Proteômica/métodos , Células-Tronco/citologiaRESUMO
Sox2 is expressed at high levels in neuroepithelial stem cells and persists in neural stem/progenitor cells throughout adulthood. We showed previously that the Sox2 regulatory region 2 (SRR2) drives strong expression in these cells. Here we generated transgenic mouse strains with the beta-geo reporter gene under the control of the SRR2 in order to examine the spatiotemporal function of this regulatory region. We show that the SRR2 functions specifically in neural stem/progenitor cells. However, unlike Nestin 2nd intronic enhancer, the SRR2 shows strong regional specificity functioning only in restricted areas of the telencephalon but not in any other portions of the central nervous system such as the spinal cord. We also show by in vitro clonogenic assay that at least some of these SRR2-functioning cells possess the hallmark properties of neural stem cells. In adult brains, we could detect strong beta-geo expression in the subventricular zone of the lateral ventricle and along the rostral migrating stream where actively dividing cells reside. Chromatin immunoprecipitation assays reveal interactions of POU and Sox factors with SRR2 in neural stem/progenitor cells. Our data also suggest that the specific recruitment of these proteins to the SRR2 in the telencephalon defines the spatiotemporal activity of the enhancer in the developing nervous system.