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1.
J Neural Transm (Vienna) ; 130(6): 839-846, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37046147

RESUMO

The clinical presentation of Parkinson's disease and atypical Parkinsonian syndromes is often heterogeneous. Additional diagnostic procedures including brain imaging and biomarker analyses can help to appreciate the various syndromes, but a precise clinical evaluation and differentiation is always necessary. To better assess the relevance of distinct clinical symptoms that arose within 1 year of disease manifestation and evaluate their indicative potential for an atypical Parkinsonian syndrome, we conducted a modified Delphi panel with seven movement disorder specialists. Five different topics with several clinical symptom items were discussed and consensus criteria were tested. This resulted in distinct symptom patterns for each atypical Parkinsonian syndrome showing the multitude of clinical involvement in each neurodegenerative disease. Strongly discriminating clinical signs were few and levels of indication were variable. A prospective validation of the assessments made is needed. This demonstrates that both clinical evaluation and elaborate additional diagnostic procedures are needed to achieve a high diagnostic standard.


Assuntos
Atrofia de Múltiplos Sistemas , Doença de Parkinson , Transtornos Parkinsonianos , Paralisia Supranuclear Progressiva , Humanos , Diagnóstico Diferencial , Atrofia de Múltiplos Sistemas/diagnóstico , Doença de Parkinson/diagnóstico , Transtornos Parkinsonianos/diagnóstico , Paralisia Supranuclear Progressiva/diagnóstico
2.
Glia ; 69(8): 2006-2022, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33942391

RESUMO

Following stroke, neuronal death takes place both in the infarct region and in brain areas distal to the lesion site including the hippocampus. The hippocampus is critically involved in learning and memory processes and continuously generates new neurons. Dysregulation of adult neurogenesis may be associated with cognitive decline after a stroke lesion. In particular, proliferation of precursor cells and the formation of new neurons are increased after lesion. Within the first week, many new precursor cells die during development. How dying precursors are removed from the hippocampus and to what extent phagocytosis takes place after stroke is still not clear. Here, we evaluated the effect of a prefrontal stroke lesion on the phagocytic activity of microglia in the dentate gyrus (DG) of the hippocampus. Three-months-old C57BL/6J mice were injected once with the proliferation marker BrdU (250 mg/kg) 6 hr after a middle cerebral artery occlusion or sham surgery. The number of apoptotic cells and the phagocytic capacity of the microglia were evaluated by means of immunohistochemistry, confocal microscopy, and 3D-reconstructions. We found a transient but significant increase in the number of apoptotic cells in the DG early after stroke, associated with impaired removal by microglia. Interestingly, phagocytosis of newly generated precursor cells was not affected. Our study shows that a prefrontal stroke lesion affects phagocytosis of apoptotic cells in the DG, a region distal to the lesion core. Whether disturbed phagocytosis might contribute to inflammatory- and maladaptive processes including cognitive impairment following stroke needs to be further investigated.


Assuntos
Microglia , Acidente Vascular Cerebral , Animais , Giro Denteado , Hipocampo/patologia , Camundongos , Camundongos Endogâmicos C57BL , Microglia/patologia , Neurogênese/fisiologia , Fagocitose , Acidente Vascular Cerebral/patologia
3.
Stem Cells ; 38(9): 1188-1201, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32473039

RESUMO

The limited proliferative capacity of neuroprogenitor cells (NPCs) within the periventricular germinal niches (PGNs) located caudal of the subventricular zone (SVZ) of the lateral ventricles together with their high proliferation capacity after isolation strongly implicates cell-extrinsic humoral factors restricting NPC proliferation in the hypothalamic and midbrain PGNs. We comparatively examined the effects of norepinephrine (NE) as an endogenous candidate regulator of PGN neurogenesis in the SVZ as well as the periventricular hypothalamus and the periaqueductal midbrain. Histological and neurochemical analyses revealed that the pattern of NE innervation of the adult PGNs is inversely associated with their in vivo NPC proliferation capacity with low NE levels coupled to high NPC proliferation in the SVZ but high NE levels coupled to low NPC proliferation in hypothalamic and midbrain PGNs. Intraventricular infusion of NE decreased NPC proliferation and neurogenesis in the SVZ-olfactory bulb system, while pharmacological NE inhibition increased NPC proliferation and early neurogenesis events in the caudal PGNs. Neurotoxic ablation of NE neurons using the Dsp4-fluoxetine protocol confirmed its inhibitory effects on NPC proliferation. Contrarily, NE depletion largely impairs NPC proliferation within the hippocampus in the same animals. Our data indicate that norepinephrine has opposite effects on the two fundamental neurogenic niches of the adult brain with norepinephrine being a negative regulator of adult periventricular neurogenesis. This knowledge might ultimately lead to new therapeutic approaches to influence neurogenesis in hypothalamus-related metabolic diseases or to stimulate endogenous regenerative potential in neurodegenerative processes such as Parkinson's disease.


Assuntos
Células-Tronco Neurais/citologia , Norepinefrina/farmacologia , Nicho de Células-Tronco , Animais , Proliferação de Células/efeitos dos fármacos , Hipocampo/citologia , Ventrículos Laterais/citologia , Mesencéfalo/citologia , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Bulbo Olfatório/citologia , Fenótipo , Receptores Adrenérgicos beta/metabolismo , Transdução de Sinais/efeitos dos fármacos
4.
J Neurosci ; 39(9): 1755-1766, 2019 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-30617211

RESUMO

Stroke robustly stimulates adult neurogenesis in the hippocampal dentate gyrus. It is currently unknown whether this process induces beneficial or maladaptive effects, but morphological and behavioral studies have reported aberrant neurogenesis and impaired hippocampal-dependent memory following stroke. However, the intrinsic function and network incorporation of adult-born granule cells (ABGCs) after ischemia is unclear. Using patch-clamp electrophysiology, we evaluated doublecortin-positive (DCX+) ABGCs as well as DCX- dentate gyrus granule cells 2 weeks after a stroke or sham operation in DCX/DsRed transgenic mice of either sex. The developmental status, intrinsic excitability, and synaptic excitability of ABGCs were accelerated following stroke, while dendritic morphology was not aberrant. Regression analysis revealed uncoupled development of intrinsic and network excitability, resulting in young, intrinsically hyperexcitable ABGCs receiving disproportionately large glutamatergic inputs. This aberrant functional maturation in the subgroup of ABGCs in the hippocampus may contribute to defective hippocampal function and increased seizure susceptibility following stroke.SIGNIFICANCE STATEMENT Stroke increases hippocampal neurogenesis but the functional consequences of the postlesional response is mostly unclear. Our findings provide novel evidence of aberrant functional maturation of newly generated neurons following stroke. We demonstrate that stroke not only causes an accelerated maturation of the intrinsic and synaptic parameters of doublecortin-positive, new granule cells in the hippocampus, but that this accelerated development does not follow physiological dynamics due to uncoupled intrinsic and synaptic maturation. Hyperexcitable immature neurons may contribute to disrupted network integration following stroke.


Assuntos
Giro Denteado/fisiopatologia , Infarto da Artéria Cerebral Média/fisiopatologia , Neurogênese , Potenciais Sinápticos , Animais , Giro Denteado/patologia , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Feminino , Ácido Glutâmico/metabolismo , Masculino , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Neurônios/metabolismo , Neurônios/fisiologia , Neuropeptídeos/genética , Neuropeptídeos/metabolismo
5.
Fortschr Neurol Psychiatr ; 88(9): 609-619, 2020 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-32957144

RESUMO

The present work provides an overview of the various nuclear medicine methods in the diagnosis of neurodegenerative parkinsonian syndromes and their respective evidence and is intended to enable practical decision-making aids in the application and interpretation of the methods and findings. The value of the procedures differs considerably in relation to the two relevant diagnostic questions. On the one hand, it is the question of whether there is a neurodegenerative parkinsonian syndrome at all, and on the other hand the question of which one. While the DAT-SPECT is undisputedly the method of choice for answering the first question (taking certain parameters into account), this method is not suitable for answering the second question. To categorise parkinsonian syndromes into idiopathic (i. e. Parkinson´s disease) or atypical, various procedures are used in everyday clinical practice including MIBG scintigraphy, and FDG-PET. We explain why FDG-PET currently is not only the most suitable of these methods to differentiate an idiopathic parkinsonian syndrome, from an atypical Parkinson's syndrome, but also enables sufficiently valid to distinguish the various atypical neurodegenerative Parkinson's syndromes (i. e. MSA, PSP and CBD) from each other and therefore should be reimbursed by health insurances.


Assuntos
Transtornos Parkinsonianos/classificação , Transtornos Parkinsonianos/diagnóstico , Diagnóstico Diferencial , Humanos , Doença de Parkinson/diagnóstico , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada de Emissão de Fóton Único
6.
Fortschr Neurol Psychiatr ; 86(S 01): S34-S42, 2018 09.
Artigo em Alemão | MEDLINE | ID: mdl-30241099

RESUMO

Epidemiological studies suggest an association of certain foods with the risk of Parkinson's disease. Also, a number of studies revaeled positive effects on disease progression by caffeine, higher uric acid and total cholesterol levels - especially in men. However, it is not yet clear whether a specific dietary concept or the effects of the intestinal microbiota on the human metabolism could play a role in the course of the disease. Given the lack of prospective nutrition studies, only general recommendations can be given: a "balanced" seasonal regional diet with emphasis on vegetables, fruits, nuts, fish, low amount of red meat, and non-processed foods with a low level of simple carbohydrates may be helpful. Especially for the elderly, a low-protein diet should be avoided. Rather, in order to prevent the development of sarcopenia and malnutrition, particular attention must be paid to adequate protein intake. The supply of vitamins B12 and D3 must be ensured - at the same time, the non-critical use of dietary supplements, especially micronutrients with presumed anti-oxidative properties, should be discouraged.


Assuntos
Dietoterapia/métodos , Gastroenteropatias/fisiopatologia , Gastroenteropatias/terapia , Terapia Nutricional/métodos , Doença de Parkinson/fisiopatologia , Doença de Parkinson/terapia , Feminino , Gastroenteropatias/etiologia , Trato Gastrointestinal/fisiopatologia , Humanos , Masculino , Doença de Parkinson/complicações , Risco
7.
BMC Neurosci ; 18(1): 31, 2017 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-28279169

RESUMO

BACKGROUND: Increased motor activity or social interactions through enriched environment are strong stimulators of grey and white matter plasticity in the adult rodent brain. In the present study we evaluated whether specific reaching training of the dominant forelimb (RT) and stimulation of unspecific motor activity through enriched environment (EE) influence the generation of distinct oligodendrocyte subpopulations in the sensorimotor cortex and corpus callosum of the adult rat brain. Animals were placed in three different housing conditions: one group was transferred to an EE, a second group received daily RT, whereas a third group remained in the standard cage. Bromodeoxyuridine (BrdU) was applied at days 2-6 after start of experiments and animals were allowed to survive for 10 and 42 days. RESULTS: Enriched environment and daily reaching training of the dominant forelimb significantly increased the number of newly differentiated GSTπ+ oligodendrocytes at day 10 and newly differentiated CNPase+ oligodendrocytes in the sensorimotor cortex at day 42. The myelin level as measured by CNPase expression was increased in the frontal cortex at day 42. Distribution of newly differentiated NG2+ subpopulations changed between 10 and 42 days with an increase of GSTπ+ subtypes and a decrease of NG2+ cells in the sensorimotor cortex and corpus callosum. Analysis of neuronal marker doublecortin (DCX) showed that more than half of NG2+ cells express DCX in the cortex. The number of new DCX+NG2+ cells was reduced by EE at day 10. CONCLUSIONS: Our results indicate for the first time that specific and unspecific motor training conditions differentially alter the process of differentiation from oligodendrocyte subpopulations, in particular NG2+DCX+ cells, in the sensorimotor cortex and corpus callosum.


Assuntos
Corpo Caloso/fisiologia , Abrigo para Animais , Destreza Motora/fisiologia , Oligodendroglia/fisiologia , Prática Psicológica , Córtex Sensório-Motor/fisiologia , 2',3'-Nucleotídeo Cíclico Fosfodiesterases/metabolismo , Animais , Antígenos/metabolismo , Bromodesoxiuridina , Corpo Caloso/citologia , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Membro Anterior/fisiologia , Lobo Frontal/citologia , Lobo Frontal/fisiologia , Masculino , Proteínas Associadas aos Microtúbulos/metabolismo , Modelos Animais , Neurogênese/fisiologia , Neuropeptídeos/metabolismo , Oligodendroglia/citologia , Proteoglicanas/metabolismo , Distribuição Aleatória , Ratos Wistar , Tempo de Reação , Córtex Sensório-Motor/citologia
8.
J Neural Transm (Vienna) ; 123(1): 31-43, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26138439

RESUMO

During the last decades, symptomatic treatment of motor symptoms of Parkinson's disease (PD) improved continuously and is reflected by long-range independency of the patient during the disease course. However, advanced stages of PD still represent an important challenge to patients, caregivers and treating physicians. In patients with advanced PD, interventional therapy strategies are increasingly applied. These device-related treatment strategies using pump-based continuous dopaminergic stimulation (CDS) or deep brain stimulation (DBS) opened new treatment options especially if motor complications predominate. Well-designed clinical studies on these interventional therapeutic approaches provided class 1 evidence for the efficacy of DBS and CDS in advanced PD and opened new perspectives for their use in earlier disease stages also. Therefore, careful selection of patients amenable to the (semi)invasive therapy options becomes more and more important and requires an interdisciplinary setting that accounts for (i) optimal patient information and awareness, (ii) selection of best individual treatment modality, (iii) training of relatives and caregivers, (iv) management of complications, and (v) follow-up care. Here, we address these topics by summarizing current state-of-the-art in patient selection, providing specificities of treatment options and troubleshooting, and defining steps towards an optimized patient-centered care. Interventional therapies pioneer in the area of individualized treatment approaches for PD, and may be complemented in the future by biomarker-based improved stratification and by closed-loop systems for adaptive therapeutic strategies. In the present review, we summarize the proceedings of an Expert Workshop on Parkinson's disease held on November 22, 2014 in Frankfurt, Germany.


Assuntos
Antiparkinsonianos/efeitos adversos , Estimulação Encefálica Profunda/métodos , Doença de Parkinson/terapia , Assistência Centrada no Paciente , Humanos , Seleção de Pacientes
9.
BMC Neurosci ; 16: 20, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25881110

RESUMO

BACKGROUND: Recovery following stroke depends on cellular plasticity in the perilesional zone (PZ). Doublecortin (DCX), a protein mainly labeling immature neurons in neurogenic niches is also highly expressed in the vicinity of focal cortical infarcts. Notably, the number of DCX+ cells positively correlates with the recovery of functional deficits after stroke though the nature and origin of these cells remains unclear. RESULTS: In the present study, we aimed to characterize the population of DCX+ cells in the vicinity of ischemic infarcts in a mouse model in detail. Employing a photothrombosis model, distinct immunohistochemical techniques, stereology and confocal microscopy, we show that: i) DCX+ cells in the perilesional zone do not constitute a homogenous population and two cell types, stellate and polar cells can be distinguished according to their morphology. ii) Stellate cells are mainly located in the lateral and medial vicinity of the insult and express astrocytic markers. iii) Polar cells are found almost exclusively in the corpus callosum region including in the preserved deep cortical layers close to the subventricular zone (SVZ). Further, they do not show any colocalisation of glial markers. Polar morphology and distribution suggest a migration towards the lesion. CONCLUSIONS: In summary, our findings provide evidence that in mice DCX+ cells in the perilesional zone of cortical infarcts comprise a distinct cell population and the majority of cells are of glial nature.


Assuntos
Proteínas Associadas aos Microtúbulos/metabolismo , Neuroglia/metabolismo , Neuropeptídeos/metabolismo , Córtex Sensório-Motor/metabolismo , Acidente Vascular Cerebral/metabolismo , Animais , Corpo Caloso/metabolismo , Corpo Caloso/patologia , Modelos Animais de Doenças , Progressão da Doença , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Imuno-Histoquímica , Masculino , Camundongos Endogâmicos C57BL , Microscopia Confocal , Neuroglia/patologia , Neurônios/metabolismo , Neurônios/patologia , Córtex Sensório-Motor/patologia , Nicho de Células-Tronco/fisiologia , Acidente Vascular Cerebral/patologia , Fatores de Tempo
10.
Hippocampus ; 23(12): 1345-58, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23929505

RESUMO

Neurogenesis in the adult dentate gyrus (DG) generates new granule neurons that differentiate in the inner one-third of the granule cell layer (GCL). The migrating precursors of these neurons arise from neural stem cells (NSCs) in the subgranular zone (SGZ). Although it is established that pathological conditions, including epilepsy and stroke, cause dispersion of granule neuron precursors, little is known about the factors that regulate their normal placement. Based on the high expression of the chemokine CXCL12 in the adult GCL and its role in guiding neuronal migration in development, we addressed the function of the CXCL12 receptor CXCR4 in adult neurogenesis. Using transgenic reporter mice, we detected Cxcr4-GFP expression in NSCs, neuronal-committed progenitors, and immature neurons of adult and aged mice. Analyses of hippocampal NSC cultures and hippocampal tissue by immunoblot and immunohistochemistry provided evidence for CXCL12-promoted phosphorylation/activation of CXCR4 receptors in NSCs in vivo and in vitro. Cxcr4 deletion in NSCs of the postnatal or mature DG using Cre technology reduced neurogenesis. Fifty days after Cxcr4 ablation in the mature DG, the SGZ showed a severe reduction of Sox2-positive neural stem/early progenitor cells, NeuroD-positive neuronal-committed progenitors, and DCX-positive immature neurons. Many immature neurons were ectopically placed in the hilus and inner molecular layer, and some developed an aberrant dendritic morphology. Only few misplaced cells survived permanently as ectopic neurons. Thus, CXCR4 signaling maintains the NSC pool in the DG and specifies the inner one-third of the GCL as differentiation area for immature granule neurons.


Assuntos
Giro Denteado/citologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Neurônios/fisiologia , Receptores CXCR4/metabolismo , Fatores Etários , Animais , Fármacos Anti-HIV/farmacologia , Apolipoproteína A-I/genética , Apolipoproteína A-I/metabolismo , Benzilaminas , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Quimiocina CXCL12/farmacologia , Ciclamos , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Regulação da Expressão Gênica no Desenvolvimento/genética , Compostos Heterocíclicos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/metabolismo , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Neurogênese/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neuropeptídeos/metabolismo , Receptores CXCR4/genética , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo
11.
NPJ Parkinsons Dis ; 9(1): 162, 2023 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-38071194

RESUMO

Progressive supranuclear palsy (PSP) is an atypical Parkinsonian disorder which results in deterioration of motor and cognitive skills, including language disorders such as impaired word retrieval. While there is evidence of successful use of tDCS to improve word fluency in PSP, little is known about the effectiveness of brain stimulation for word retrieval in sentence context. Therefore, we investigated whether tDCS reduces sentence completion time in PSP patients. In this sham-controlled, triple-blinded crossover study, anodal tDCS (atDCS) was applied over the left Broca's area at 2 mA for 20 min (n = 23). In contrast to patients with multiple system atrophy (MSA), also an atypical Parkinsonian disorder, and healthy elderlies, sentence completion improved in PSP patients when tDCS was applied. The improvement in word fluency reported in previous studies using other electrode positions was not replicated. By using atDCS of the left Broca's area, we were able to demonstrate a difference between the two movement disorders. The obtained insight could be helpful to improve language therapy of these disorders.

12.
Parkinsonism Relat Disord ; 114: 105769, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37531837

RESUMO

INTRODUCTION: Morphological alterations of the vagus nerve (VN) in Parkinson's disease (PD) are discussed controversially. Several studies reported no difference in VN cross-sectional area (CSA) in PD patients in nerve ultrasound, others found a reduced CSA interpreted as atrophy of the VN and involvement of the dorsal nucleus of VN. METHODS: In a prospective comparative cross-sectional study, CSA of the VN bilaterally and the right ulnar nerve, clinical PD scales, non-motor symptoms and autonomic tests were compared between 49 PD patients and 24 healthy controls. Nerve ultrasound was performed by two independent investigators, patients and controls were compared at Bonferroni corrected p < 0.025 using results of both investigators and averaged results. Blinding included CSA measurements and PD scores, but not PD diagnosis. RESULTS: Bilateral averaged VN CSA was significantly lower in PD patients than in controls (Right VN PD mean 2.70 mm2 SD 0.69, controls 3.30 mm2 SD 0.49, p < 0.001. Left VN PD mean 2.45 mm2 SD 0.57, controls 2.77 mm2 SD 0.46, p = 0.012). No difference was found in the ulnar nerve. There was a weak negative correlation between the right VN CSA and the Unified Parkinson Disease Rating Scale (-0.08 mm2 per 10 points). The area under the receiver operating characteristic curve for the right VN was 0.78 (p < 0.001). CONCLUSION: The present results support the hypothesis of atrophy of the VN in PD. Reduction of VN CSA is a weak marker of disease progression. Nerve ultrasound of the VN might represent a supplementary method in diagnosis of PD.


Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/diagnóstico por imagem , Estudos Prospectivos , Estudos Transversais , Nervo Vago/diagnóstico por imagem , Atrofia
13.
Cells ; 12(4)2023 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-36831319

RESUMO

Ischemic lesions stimulate adult neurogenesis in the dentate gyrus, however, this is not associated with better cognitive function. Furthermore, increased neurogenesis is associated with the formation of aberrant neurons. In a previous study, we showed that a running task after a stroke not only increases neurogenesis but also the number of aberrant neurons without improving general performance. Here, we determined whether stimulation in an enriched environment after a lesion could increase neurogenesis and cognitive function without enhancing the number of aberrant neurons. After an ischemic stroke induced by MCAO, animals were transferred to an enriched environment containing a running wheel, tunnels and nest materials. A GFP-retroviral vector was delivered on day 3 post-stroke and a modified water maze test was performed 6 weeks after the lesion. We found that the enriched environment significantly increased the number of new neurons compared with the unstimulated stroke group but not the number of aberrant cells after a lesion. Increased neurogenesis after environmental enrichment was associated with improved cognitive function. Our study showed that early placement in an enriched environment after a stroke lesion markedly increased neurogenesis and flexible learning but not the formation of aberrant neurons, indicating that rehabilitative training, as a combination of running wheel training and enriched environment housing, improved functional and structural outcomes after a stroke.


Assuntos
Cognição , Acidente Vascular Cerebral , Camundongos , Animais , Cognição/fisiologia , Acidente Vascular Cerebral/patologia , Neurônios/fisiologia , Neurogênese/fisiologia , Hipocampo/patologia
14.
Stroke ; 43(9): 2468-75, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22738919

RESUMO

BACKGROUND AND PURPOSE: Adult neurogenesis in the dentate gyrus is a unique form of brain plasticity that is strongly stimulated after stroke. We investigate the morphological properties of new granule cells, which are born and develop after the ischemic insult, and query whether these adult-born neurons properly integrate into the pre-existing hippocampal circuitries. METHODS: Two well-established models were used to induce either small cortical infarcts (photothrombosis model) or large territorial infarcts (transient middle cerebral artery occlusion model). New granule cells were labeled 4 days after the initial insult by intrahippocampal injection of a retroviral vector encoding green fluorescent protein and newborn neurons were morphologically analyzed using a semiautomatic Neurolucida system and confocal laser scanning microscopy at 6 weeks. RESULTS: Approximately 5% to 10% of newborn granule cells displayed significant morphological abnormalities comprising additional basal dendrites and, after middle cerebral artery occlusion, also ectopic cell position. The extent of morphological abnormalities was higher after large territorial infarcts and seems to depend on the severity of ischemic damage. An increased portion of mushroom spines in aberrant neurons suggests stable synaptic integration. However, poststroke generated granule cells with regular appearance also demonstrate alterations in dendritic complexity and spine morphology. CONCLUSIONS: The remarkable stimulation of dentate neurogenesis after stroke coincides with an increased rate of aberrantly integrated neurons, which may contribute to functional impairments and, hypothetically, favor pathogenesis of adjustment disorders, cognitive deficits, or epilepsy often seen in stroke patients.


Assuntos
Neurogênese/fisiologia , Retroviridae/genética , Acidente Vascular Cerebral/patologia , Animais , Isquemia Encefálica/patologia , Grânulos Citoplasmáticos/patologia , Grânulos Citoplasmáticos/ultraestrutura , Dendritos/patologia , Dendritos/ultraestrutura , Espinhas Dendríticas/patologia , Espinhas Dendríticas/ultraestrutura , Giro Denteado/patologia , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Imuno-Histoquímica , Infarto da Artéria Cerebral Média/patologia , Trombose Intracraniana/patologia , Proteínas Luminescentes/genética , Masculino , Plasticidade Neuronal/fisiologia , Neurônios/patologia , Neurônios/ultraestrutura , Ratos , Ratos Wistar , Proteína Vermelha Fluorescente
15.
Neurobiol Dis ; 46(2): 431-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22366183

RESUMO

The adult brain responds to diverse pathologies such as stroke with increased generation of neurons in the dentate gyrus of the hippocampus. However, only little is known regarding the functional integration of newborn neurons into pre-existing neuronal circuits. In this study, we investigated whether newborn neurons generated after experimental stroke are recruited for different behavioral tasks. Adult mice received photochemical cortical infarcts in the sensorimotor cortex and proliferating cells were labeled using the proliferation marker, bromodeoxyuridine. Eight weeks after stroke induction, the animals were trained to perform either a spatiotemporal task or a sensorimotor task. Immediate early gene expression (c-fos, Zif268) in newborn neurons was analyzed directly after the last session. Using this approach, we demonstrate that post-stroke generated neurons are recruited within the hippocampal networks. The sensorimotor task activates significantly more newborn neurons compared to the spatiotemporal task. Further experiments employing the two well-established stimulators of neurogenesis, enriched environment and voluntary wheel running, both significantly increase post-stroke neurogenesis in the dentate gyrus but do not affect the percentage of recruited neurons compared to controls. Significantly, the spatiotemporal task leads to a higher portion of activated newborn neurons in the granule cell layer, suggesting a specific spatial activation pattern of new neurons in the dentate gyrus.


Assuntos
Movimento Celular/fisiologia , Hipocampo/citologia , Hipocampo/fisiologia , Neurogênese/fisiologia , Neurônios/fisiologia , Acidente Vascular Cerebral/patologia , Animais , Animais Recém-Nascidos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Rede Nervosa/citologia , Rede Nervosa/fisiologia , Desempenho Psicomotor/fisiologia
16.
Mov Disord ; 27(8): 1019-25, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22730050

RESUMO

A number of neuropathological studies have demonstrated that the olfactory system is among the first brain regions affected in Parkinson's disease (PD). These findings correlate with pathophysiological and pathological data that show a loss in olfactory bulb (OB) volume in patients with PD. However, to date, MRI has not been a reliable method for the in vivo detection of this volumetric loss in PD. Using a 3.0-Tesla MRI constructive interference in the steady-state sequence, OB volume was evaluated in patients with PD (n = 16) and healthy control subjects (n = 16). A significant loss of OB volume was observed in patients with PD, compared to the healthy control group (91.2 ± 15.72 versus 131.4 ± 24.56 mm(3) , respectively). Specifically, decreased height of the left OB appears to be a reliable parameter that is adaptable to clinical practice and significantly correlates with OB volume loss in patients with idiopathic PD. Measuring both the volume and height of the OB by MRI may be a valuable method for the clinical investigation of PD.


Assuntos
Bulbo Olfatório/patologia , Doença de Parkinson/patologia , Idoso , Interpretação Estatística de Dados , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Odorantes , Percepção Olfatória
17.
Proc Natl Acad Sci U S A ; 106(27): 11336-41, 2009 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-19549869

RESUMO

In the adult dentate gyrus, radial glia-like cells represent putative stem cells generating neurons and glial cells. Here, we combined patch-clamp recordings, biocytin filling, immunohistochemistry, single-cell transcript analysis, and mouse transgenics to test for connexin expression and gap junctional coupling of radial glia-like cells and its impact on neurogenesis. Radial glia-like cells were identified in mice expressing EGFP under control of the nestin and gfap promoters. We show that a majority of Radial glia-like cells are coupled and express Cx43. Neuronal precursors were not coupled. Mice lacking Cx30 and Cx43 in GFAP-positive cells displayed almost complete inhibition of proliferation and a significant decline in numbers of radial glia-like cells and granule neurons. Inducible virus-mediated ablation of connexins in the adult hippocampus also reduced neurogenesis. These findings strongly suggest the requirement of connexin expression by radial glia-like cells for intact neurogenesis in the adult brain and point to possible communication pathways of these cells.


Assuntos
Conexina 43/metabolismo , Conexinas/metabolismo , Giro Denteado/metabolismo , Neurogênese , Neuroglia/metabolismo , Animais , Bromodesoxiuridina/metabolismo , Contagem de Células , Proliferação de Células , Conexina 30 , Grânulos Citoplasmáticos/metabolismo , Giro Denteado/citologia , Junções Comunicantes/metabolismo , Deleção de Genes , Humanos , Lisina/análogos & derivados , Lisina/metabolismo , Camundongos , Camundongos Knockout , Neuroglia/citologia , Isoformas de Proteínas/metabolismo
18.
Exp Neurol ; 338: 113591, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33387461

RESUMO

Sepsis associated encephalopathy (SAE) is a major complication of patients surviving sepsis with a prevalence up to 70%. Although the initial pathophysiological events of SAE are considered to arise during the acute phase of sepsis, there is increasing evidence that SAE leads to persistent brain dysfunction with severe cognitive decline in later life. Previous studies suggest that the hippocampal formation is particularly involved leading to atrophy in later stages. Thereby, the underlying cellular mechanisms are only poorly understood. Here, we hypothesized that endogenous neural stems cells and adult neurogenesis in the hippocampus are impaired following sepsis and that these changes may contribute to persistent cognitive dysfunction when the animals have physically fully recovered. We used the murine sepsis model of peritoneal contamination and infection (PCI) and combined different labeling methods of precursor cells with confocal microscopy studies to assess the neurogenic niche in the dentate gyrus at day 42 postsepsis. We found that following sepsis i) gliogenesis is increased, ii) the absolute number of radial glia-like cells (type 1 cells), which are considered the putative stem cells, is significantly reduced, iii) the generation of new neurons is not significantly altered, while iv) the synaptic spine maturation of new neurons is impaired with a shift to expression of more immature and less mature spines. In conclusion, sepsis mainly leads to depletion of the neural stem cell pool and enhanced gliogenesis in the dentate gyrus which points towards an accelerated aging of the hippocampus due to septic insult.


Assuntos
Células Ependimogliais/patologia , Hipocampo/patologia , Células-Tronco Neurais/patologia , Neurogênese/fisiologia , Encefalopatia Associada a Sepse/patologia , Animais , Camundongos , Camundongos Endogâmicos C57BL
19.
BMC Neurosci ; 11: 146, 2010 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-21083887

RESUMO

BACKGROUND: It is well known that focal ischemia increases neurogenesis in the adult dentate gyrus of the hippocampal formation but the cellular mechanisms underlying this proliferative response are only poorly understood. We here investigated whether precursor cells which constitutively proliferate before the ischemic infarct contribute to post-ischemic neurogenesis. To this purpose, transgenic mice expressing green fluorescent protein (GFP) under the control of the nestin promoter received repetitive injections of the proliferation marker bromodeoxyuridine (BrdU) prior to induction of cortical infarcts. We then immunocytochemically analyzed the fate of these BrdU-positive precursor cell subtypes from day 4 to day 28 after the lesion. RESULTS: Quantification of BrdU-expressing precursor cell populations revealed no alteration in number of radial glia-like type 1 cells but a sequential increase of later precursor cell subtypes in lesioned animals (type 2a cells at day 7, type 3 cells/immature neurons at day 14). These alterations result in an enhanced survival of mature neurons 4 weeks postinfarct. CONCLUSIONS: Focal cortical infarcts recruit dentate precursor cells generated already before the infarct and significantly contribute to an enhanced neurogenesis. Our findings thereby increase our understanding of the complex cellular mechanisms of postlesional neurogenesis.


Assuntos
Proliferação de Células , Infarto Cerebral/patologia , Giro Denteado/patologia , Células-Tronco Neurais/patologia , Neurogênese/fisiologia , Plasticidade Neuronal/fisiologia , Células-Tronco/patologia , Animais , Infarto Cerebral/fisiopatologia , Giro Denteado/citologia , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos , Células-Tronco Neurais/citologia , Células-Tronco/citologia
20.
J Am Geriatr Soc ; 68(7): 1469-1475, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32198768

RESUMO

OBJECTIVES: Although delirium is often investigated, little is known about the outcomes of patients having acute neuropsychological changes at a single time point without fulfilling the criteria of full delirium. Our aim was to determine point prevalence, predictors, and long-term outcomes of delirium and acute neuropsychological changes in patients aged 60 years and older across different departments of a university hospital with general inpatient care. DESIGN: Prospective observational study. SETTING: University hospital excluding psychiatric wards. PARTICIPANTS: At baseline, 669 patients were assessed, and follow-ups occurred at months 6, 12, 18, and 36. MEASUREMENTS: Measurements were obtained using the Confusion Assessment Method (CAM), comprehensive geriatric assessment, health-related quality of life, functional state (month 6), and mortality rates (months 6, 12, 18, and 36). Subjects were classified into (1) patients with delirium according to the CAM, (2) patients with only two positive CAM items (2-CAM state), and (3) patients without delirium. RESULTS: Delirium was present in 10.8% and the 2-CAM state in an additional 12.7% of patients. Highest prevalence of delirium was observed in medical and surgical intensive care units and neurosurgical wards. Cognitive restrictions, restricted mobility, electrolyte imbalance, the number of medications per day, any fixations, and the presence of a urinary catheter predicted the presence of delirium and 2-CAM-state. The mean Karnofsky Performance Score and EuroQol-5D were comparable between delirium and the 2-CAM state after 6 months. The 6-, 12-, 18-, and 36-month mortality rates of patients with delirium and the 2-CAM state were comparable. The nurses' evaluation of distinct patients showed high specificity (89%) but low sensitivity (53%) for the detection of delirium in wide-awake patients. CONCLUSION: Patients with an acute change or fluctuation in mental status or inattention with one additional CAM symptom (ie, disorganized thinking or an altered level of consciousness) have a similar risk for a lower quality of life and death as patients with delirium. J Am Geriatr Soc 68:1469-1475, 2020.


Assuntos
Confusão/diagnóstico , Delírio/diagnóstico , Avaliação Geriátrica , Hospitalização , Avaliação de Resultados da Assistência ao Paciente , Idoso , Cognição , Delírio/psicologia , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Inquéritos e Questionários
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