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1.
Biomed Khim ; 65(5): 366-373, 2019 Aug.
Artigo em Russo | MEDLINE | ID: mdl-31666407

RESUMO

Neurogenesis is a complex process which governs embryonic brain development and is importants for brain plasticity throughout the whole life. Postnatal neurogenesis occurs in neurogenic niches that regulate the processes of proliferation and differentiation of stem and progenitor cells under the action of stimuli that trigger the mechanisms of neuroplasticity. Cells of glial and endothelial origin are the key regulators of neurogenesis. It is known that physiological neurogeneses is crucial for memory formation, whereas reparative neurogenesis provides partial repair of altered brain structure and compensation of neurological deficits caused by brain injury. Dysregulation of neurogenesis is a characteristics of various neurodevelopmental and neurodegenerative diseases, particularly, Alzheimer's disease which is very important medical and social problem. In the in vitro model of the neurogenic niche using hippocampal neurospheres as a source of stem/progenitor cells and astrocytes, we studied effects of astrocyte activation on the expression of markers of different stages of cell proliferation and differentiation. We found that aberrant mechanisms of development of stem and progenitor cells, caused by the beta-amyloid (Aß1-42), can be partially restored by targeted activation of GFAP-expressing cells in the neurogenic niche.


Assuntos
Peptídeos beta-Amiloides/farmacologia , Astrócitos/citologia , Células-Tronco Neurais/citologia , Neurogênese , Fragmentos de Peptídeos/farmacologia , Diferenciação Celular , Células Cultivadas , Hipocampo/citologia , Humanos
2.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 35(4): 308-311, 2019 Jul 28.
Artigo em Chinês | MEDLINE | ID: mdl-31701712

RESUMO

OBJECTIVE: To observe the expressions of sphingosine kinase 1 (SphK1) and sphingosine-1-phosphate receptor 2 (S1PR2) in hippocampus of epileptic rats and to investigate the pathogenesis of SphK1 and S1PR2 in epilepsy. METHODS: One hundred and eight male Sprague-Dawley (SD) rats were randomly divided into control group (n=48) and pilocarpine (PILO) group (n=60). A robust convulsive status epilepticus (SE) was induced in PILO group rats by the application of pilocarpine. Control group rats were injected with respective of physiological saline. Pilocarpine group was randomly divided into 6 subgroups (n=8): acute group (E6 h, E1 d, E3 d), latent group (E7 d) and chronic group (E30 d, E56 d). Each subgroup has 8 control rats and 8 epileptic rats. Hippocampal tissue and brain slices were obtained from control rats and rats subjected to the Li-PILO model of epilepsy at 6 h, 1 d, 3 d,7 d,30 d and 56 d after status epilepticus (SE). Western blot technique was used to determine the expressions of SphK1 and S1PR2 in hippocampus at different point of time after pilocarpine treatment. Immunofluorescence was applied to detect the activation and proliferation of hippocampal astrocytes and the localization of SphK1 and S1PR2 in rat hippocampal astrocytes. RESULTS: Compared with control group, the levels of SphK1 in acute phase (E3 d), latent phase (E7 d) and chronic phase (E30 d, E56 d) were significantly increased while the expressions of S1PR2 were decreased in acute phase (E3 d), latent phase (E7 d) and chronic phase (E30 d, E56 d)(P<0.05 or P<0.01). Immunofluorescence results showed astrocyte activation and proliferation in hippocampus of epileptic (E7 d) rats (P<0.05). Confocal microscopy confirmed the preferential expressions of SphK1 and S1PR2 in epileptic rat(E7 d)hippocampal astrocytes. CONCLUSION: The results indicate that SphK1 and S1PR2 may play an important role in the pathogenesis of epilepsy by regulating the activation and proliferation of hippocampal astrocytes and altering neuronal excitability.


Assuntos
Epilepsia/enzimologia , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Receptores de Lisoesfingolipídeo/metabolismo , Animais , Astrócitos/enzimologia , Epilepsia/fisiopatologia , Hipocampo/citologia , Hipocampo/enzimologia , Masculino , Pilocarpina , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
3.
Phys Rev Lett ; 123(17): 178103, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31702278

RESUMO

We develop a phenomenological coarse-graining procedure for activity in a large network of neurons, and apply this to recordings from a population of 1000+ cells in the hippocampus. Distributions of coarse-grained variables seem to approach a fixed non-Gaussian form, and we see evidence of scaling in both static and dynamic quantities. These results suggest that the collective behavior of the network is described by a nontrivial fixed point.


Assuntos
Hipocampo/fisiologia , Modelos Neurológicos , Neurônios/fisiologia , Animais , Hipocampo/citologia , Humanos , Camundongos , Rede Nervosa/citologia , Rede Nervosa/fisiologia , Neurônios/citologia
4.
Biol Res ; 52(1): 53, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31542051

RESUMO

BACKGROUND: Oxidative stress is the hallmark of diabetic encephalopathy, which may be caused by hyperglycaemic toxicity. We aimed to discover pharmacologic targets to restore redox homeostasis. We identified the transcription factor Nrf2 as such a target. METHODS: HT22 cells were cultured in 25 or 50 mM D-glucose with various concentrations of sulforaphane (SFN) (from 1.25 to 5.0 µM). Cell viability was tested with the Cell Counting Kit-8 assay. Reactive oxygen species (ROS) production was detected with an inverted fluorescence microscope using the dichlorodihydrofluorescein-diacetate fluorescent probe. The expression of NF-E2-related factor 2 (Nrf2), haem oxygenase-1 (HO-1) and nuclear factor-κB (NF-κB) at the mRNA and protein levels was detected by reverse transcription quantitative polymerase chain reaction and western blotting. RESULT: We found that a high glucose concentration (50 mM) increased the generation of ROS, downregulated the expression of Nrf2/HO-1 and upregulated the expression of NF-κB. Moreover, HT22 cell viability significantly decreased after culture in high-glucose medium for 24, 48 and 72 h, whereas the activation of the Nrf2/HO-1 pathway using a pharmacological Nrf2 activator abrogated this high-glucose-induced toxicity. CONCLUSION: This study suggests that the activation of the Nrf2-ARE signalling pathway might be a therapeutic target for the treatment of diabetic encephalopathy.


Assuntos
Glucose/toxicidade , Hipocampo/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/agonistas , Neuroproteção , Animais , Western Blotting , Linhagem Celular , Eletroforese em Gel de Campo Pulsado , Imunofluorescência , Hipocampo/citologia , Camundongos , Espécies Reativas de Oxigênio , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
5.
Nat Neurosci ; 22(10): 1718-1730, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31501571

RESUMO

Activity-driven transcription plays an important role in many brain processes, including those underlying memory and epilepsy. Here we combine genetic tagging of nuclei and ribosomes with RNA sequencing, chromatin immunoprecipitation with sequencing, assay for transposase-accessible chromatin using sequencing and Hi-C to investigate transcriptional and chromatin changes occurring in mouse hippocampal excitatory neurons at different time points after synchronous activation during seizure and sparse activation by novel context exploration. The transcriptional burst is associated with an increase in chromatin accessibility of activity-regulated genes and enhancers, de novo binding of activity-regulated transcription factors, augmented promoter-enhancer interactions and the formation of gene loops that bring together the transcription start site and transcription termination site of induced genes and may sustain the fast reloading of RNA polymerase complexes. Some chromatin occupancy changes and interactions, particularly those driven by AP1, remain long after neuronal activation and could underlie the changes in neuronal responsiveness and circuit connectivity observed in these neuroplasticity paradigms, perhaps thereby contributing to metaplasticity in the adult brain.


Assuntos
Epigenômica , Hipocampo/fisiologia , Neurônios/fisiologia , Animais , Cromatina/genética , Elementos Facilitadores Genéticos/genética , Genes Precoces/genética , Hipocampo/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Plasticidade Neuronal/genética , Plasticidade Neuronal/fisiologia , Regiões Promotoras Genéticas/genética , Convulsões/genética , Convulsões/fisiopatologia , Estado Epiléptico/genética , Estado Epiléptico/fisiopatologia , Fator de Transcrição AP-1/genética , Transcrição Genética/genética , Transcrição Genética/fisiologia
6.
Adv Exp Med Biol ; 1169: 31-53, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31487017

RESUMO

The discovery of neural stem cells in the adult mammalian hippocampus has attracted attention and controversy, which both continue to this day. Hippocampal neural stem cells and their immediate progeny, amplifying neuroprogenitor cells, give rise to neurons and astrocytes in the region. Envisioned as possible key for tissue regeneration, whether mobilized endogenously or transplanted exogenously, neural stem cells have been in the eye of both public and science over the course of the past 20 years. These cells are a heterogeneous population, and here, we review different aspects of their heterogeneity from morphology to metabolism and response to different stimuli.


Assuntos
Hipocampo , Células-Tronco Neurais , Animais , Astrócitos/citologia , Diferenciação Celular , Hipocampo/citologia , Humanos , Células-Tronco Neurais/citologia , Neurogênese , Neurônios/citologia
7.
Nat Neurosci ; 22(10): 1709-1717, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31451803

RESUMO

Nervous system function relies on complex assemblies of distinct neuronal cell types that have unique anatomical and functional properties instructed by molecular programs. Alternative splicing is a key mechanism for the expansion of molecular repertoires, and protein splice isoforms shape neuronal cell surface recognition and function. However, the logic of how alternative splicing programs are arrayed across neuronal cells types is poorly understood. We systematically mapped ribosome-associated transcript isoforms in genetically defined neuron types of the mouse forebrain. Our dataset provides an extensive resource of transcript diversity across major neuron classes. We find that neuronal transcript isoform profiles reliably distinguish even closely related classes of pyramidal cells and inhibitory interneurons in the mouse hippocampus and neocortex. These highly specific alternative splicing programs selectively control synaptic proteins and intrinsic neuronal properties. Thus, transcript diversification via alternative splicing is a central mechanism for the functional specification of neuronal cell types and circuits.


Assuntos
Processamento Alternativo/genética , Neurônios/fisiologia , Ribossomos/genética , Transcrição Genética/genética , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica/genética , Hipocampo/citologia , Interneurônios/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neocórtex/citologia , Neurônios/classificação , Terminações Pré-Sinápticas/metabolismo , Prosencéfalo/citologia , Isoformas de Proteínas/genética , Células Piramidais/fisiologia
8.
Adv Exp Med Biol ; 1155: 889-903, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468455

RESUMO

Diabetes causes memory loss. Hippocampus is responsible for memory and increased apoptosis was found in diabetes patients. Taurine improved memory in diabetes condition. However, mechanism is unclear. In current study, hippocampal cell line HT-22 cells were subjected to analysis as five groups i.e. Control, High glucose (HG) at concentration of 150 mM, HG + 10 mM (T1), 20 mM (T2) and 40 mM (T3) taurine solution. TUNEL assay showed that HG increased the number of apoptotic cell significantly while taurine reduced apoptosis. Taurine increased phosphorylation of Akt in HT-22 cell treated with HG, and increased phosphorylation of Bad (p-Bad) was seen suggesting involvement of Akt/Bad signaling pathway. Expression of Bcl-2 was reduced in HG group but taurine improved this. Bax expression showed opposite trend. This indicated that taurine may reduce apoptosis by controlling balance of Bcl-2 and Bax. When the activation of Akt was blocked by using of perifosine, the effect of taurine disappears either partially or altogether. Thus, it was clear that taurine reduces apoptosis via Akt/Bad pathway in HT-22 cells exposed to HG which further improves downstream balance of Bcl-2 and Bax. This mechanism may be involved in apoptosis of hippocampus cells in diabetic condition.


Assuntos
Apoptose , Neurônios/efeitos dos fármacos , Taurina/farmacologia , Animais , Linhagem Celular , Glucose , Hipocampo/citologia , Camundongos , Fosforilação , Transdução de Sinais
9.
Chem Pharm Bull (Tokyo) ; 67(7): 699-706, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257325

RESUMO

In our search for novel orally active α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonists, we found that conversion of an allyl group in the lead compound 2-[allyl(4-methylphenyl)amino]-4H-pyrido[3,2-e][1,3]thiazin-4-one (4) to a 2-cyanoethyl group significantly increased inhibitory activity against AMPA receptor-mediated kainate-induced toxicity in rat hippocampal cultures. Here, we synthesized 10 analogs bearing a 2-cyanoethyl group and administered them to mice to evaluate their anticonvulsant activity in maximal electroshock (MES)- and pentylenetetrazol (PTZ)-induced seizure tests, and their effects on motor coordination in a rotarod test. 3-{(4-Oxo-4H-pyrido[3,2-e][1,3]thiazin-2-yl)[4-(trifluoromethoxy)phenyl]amino}propanenitrile (25) and 3-[(2,2-difluoro-2H-1,3-benzodioxol-5-yl)(4-oxo-4H-pyrido[3,2-e][1,3]thiazin-2-yl)amino]propanenitrile (27) exhibited potent anticonvulsant activity in both seizure tests and induced minor motor disturbances as indicated in the rotarod test. The protective index values of 25 and 27 for MES-induced seizures (10.7 and 12.0, respectively) and PTZ-induced seizures (6.0 and 5.6, respectively) were considerably higher compared with those of YM928 (5) and talampanel (1).


Assuntos
Anticonvulsivantes/síntese química , Nitrilos/química , Receptores de AMPA/antagonistas & inibidores , Administração Oral , Animais , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Microssomos Hepáticos/metabolismo , Nitrilos/farmacologia , Nitrilos/uso terapêutico , Pentilenotetrazol/toxicidade , Ratos , Ratos Wistar , Receptores de AMPA/metabolismo , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Convulsões/veterinária , Relação Estrutura-Atividade
10.
Nat Commun ; 10(1): 2968, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273206

RESUMO

NMDA receptor-dependent long-term depression (LTD) in the hippocampus is a well-known form of synaptic plasticity that has been linked to different cognitive functions. The core mechanism for this form of plasticity is thought to be entirely neuronal. However, we now demonstrate that astrocytic activity drives LTD at CA3-CA1 synapses. We have found that LTD induction enhances astrocyte-to-neuron communication mediated by glutamate, and that Ca2+ signaling and SNARE-dependent vesicular release from the astrocyte are required for LTD expression. In addition, using optogenetic techniques, we show that low-frequency astrocytic activation, in the absence of presynaptic activity, is sufficient to induce postsynaptic AMPA receptor removal and LTD expression. Using cell-type-specific gene deletion, we show that astrocytic p38α MAPK is required for the increased astrocytic glutamate release and astrocyte-to-neuron communication during low-frequency stimulation. Accordingly, removal of astrocytic (but not neuronal) p38α abolishes LTD expression. Finally, this mechanism modulates long-term memory in vivo.


Assuntos
Astrócitos/enzimologia , Hipocampo/fisiologia , Memória de Longo Prazo/fisiologia , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Animais , Comportamento Animal/fisiologia , Condicionamento (Psicologia)/fisiologia , Medo/fisiologia , Feminino , Ácido Glutâmico/metabolismo , Hipocampo/citologia , Depressão Sináptica de Longo Prazo/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/fisiologia , Optogenética , Técnicas de Patch-Clamp , Potenciais Sinápticos/fisiologia
11.
Nat Commun ; 10(1): 3090, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300647

RESUMO

The role of brain somatic mutations in Alzheimer's disease (AD) is not well understood. Here, we perform deep whole-exome sequencing (average read depth 584×) in 111 postmortem hippocampal formation and matched blood samples from 52 patients with AD and 11 individuals not affected by AD. The number of somatic single nucleotide variations (SNVs) in AD brain specimens increases significantly with aging, and the rate of mutation accumulation in the brain is 4.8-fold slower than that in AD blood. The putatively pathogenic brain somatic mutations identified in 26.9% (14 of 52) of AD individuals are enriched in PI3K-AKT, MAPK, and AMPK pathway genes known to contribute to hyperphosphorylation of tau. We show that a pathogenic brain somatic mutation in PIN1 leads to a loss-of-function mutation. In vitro mimicking of haploinsufficiency of PIN1 aberrantly increases tau phosphorylation and aggregation. This study provides new insights into the genetic architecture underlying the pathogenesis of AD.


Assuntos
Doença de Alzheimer/genética , Peptidilprolil Isomerase de Interação com NIMA/genética , Agregação Patológica de Proteínas/genética , Proteínas tau/metabolismo , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/genética , Doença de Alzheimer/patologia , Animais , Linhagem Celular Tumoral , Feminino , Técnicas de Silenciamento de Genes , Haploinsuficiência , Hipocampo/citologia , Hipocampo/patologia , Humanos , Mutação com Perda de Função , Masculino , Camundongos , Pessoa de Meia-Idade , Taxa de Mutação , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Neurônios , Fosforilação/genética , Polimorfismo de Nucleotídeo Único , Agregação Patológica de Proteínas/patologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sequenciamento Completo do Exoma
12.
Nat Neurosci ; 22(8): 1357-1370, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31285615

RESUMO

The medial prefrontal cortex (mPFC) contains populations of GABAergic interneurons that play different roles in cognition and emotion. Their local and long-range inputs are incompletely understood. We used monosynaptic rabies viral tracers in combination with fluorescence micro-optical sectioning tomography to generate a whole-brain atlas of direct long-range inputs to GABAergic interneurons in the mPFC of male mice. We discovered that three subtypes of GABAergic interneurons in two areas of the mPFC are innervated by same upstream areas. Input from subcortical upstream areas includes cholinergic neurons from the basal forebrain and serotonergic neurons (which co-release glutamate) from the raphe nuclei. Reconstruction of single-neuron morphology revealed novel substantia innominata-anteromedial thalamic nucleus-mPFC and striatum-anteromedial thalamic nucleus-mPFC circuits. Based on the projection logic of individual neurons, we classified cortical and hippocampal input neurons into several types. This atlas provides the anatomical foundation for understanding the functional organization of the mPFC.


Assuntos
Mapeamento Encefálico/métodos , Interneurônios/fisiologia , Córtex Pré-Frontal/anatomia & histologia , Córtex Pré-Frontal/citologia , Ácido gama-Aminobutírico/fisiologia , Animais , Contagem de Células , Hipocampo/citologia , Hipocampo/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sistema Nervoso Parassimpático/citologia , Sistema Nervoso Parassimpático/fisiologia , Prosencéfalo/anatomia & histologia , Prosencéfalo/citologia , Núcleos da Rafe/citologia , Núcleos da Rafe/fisiologia , Neurônios Serotoninérgicos/fisiologia , Tálamo/citologia , Tálamo/fisiologia
13.
Nat Methods ; 16(8): 699-702, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31308551

RESUMO

Chemical inhibitors have revealed requirements for protein synthesis that drive cellular plasticity. We developed a genetically encodable protein synthesis inhibitor (gePSI) to achieve cell-type-specific temporal control of protein synthesis. Controlled expression of the gePSI in neurons or glia resulted in rapid, potent and reversible cell-autonomous inhibition of protein synthesis. Moreover, gePSI expression in a single neuron blocked the structural plasticity induced by single-synapse stimulation.


Assuntos
Engenharia Genética , Hipocampo/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , Neurônios/metabolismo , Biossíntese de Proteínas , Inibidores da Síntese de Proteínas/farmacologia , Sinapses/metabolismo , Animais , Células Cultivadas , Células HeLa , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Humanos , Neuroglia/citologia , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Inibidores da Síntese de Proteínas/química , Ratos , Sinapses/efeitos dos fármacos
14.
Int. j. morphol ; 37(2): 576-583, June 2019. graf
Artigo em Inglês | LILACS | ID: biblio-1002261

RESUMO

Antidepressants use during pregnancy was associated with an increased risk of autism spectrum disorders. Animal models based on early life alterations in serotonin availability replicate some of the anatomical and behavioral abnormalities observed in autistic individuals. In recent years there has been a growing interest in the possible role of the hippocampus in autism. The aim of study is to examine the effects of neonatal antidepressant (CTM) exposure during a sensitive period of brain development on pyramidal and granule cells density of hippocampal formation. We examined the pyramidal and granular cells density of dorsal hippocampus using Nissl stained sections obtained from neonatal citalopram (CTM) exposed rats (5 mg/kg, twice daily, s.c.), from postnatal day 8 to 21 (PN8-21), saline and non-exposed rats. The density of pyramidal cells was significantly increased by 10.2 % in CA1, 10.6 % in CA3 and 13.2 % in CA4 in CTM treated compared with non-treated or saline treated animals (p<0.0001). The density of granule cells in the dentate gyrus was significantly increased by 12.0 % in CTM treated compared with non-treated or saline treated animals (p<0.0001). These findings were obtained only from male rats, suggesting a sexual dimorphism in neural development after SSRI exposure. These data suggest that the neonatal exposure to CTM may induce long-lasting changes in the hippcampal formation in adults, and such effects appear to preferentially target males.


El uso de antidepresivos durante el embarazo se asoció con un mayor riesgo de trastornos del espectro autista. Los modelos animales basados en alteraciones tempranas de la vida en la disponibilidad de serotonina replican algunas de las anomalías anatómicas y de comportamiento observadas en individuos autistas. En los últimos años ha habido un interés creciente en el posible papel del hipocampo en el autismo. El objetivo del estudio fue examinar los efectos de la exposición al antidepresivo neonatal (CTM) durante un período sensible del desarrollo cerebral en la densidad de las células piramidales y granulares de la formación del hipocampo. Examinamos la densidad de las células piramidales y granulares del hipocampo dorsal utilizando secciones teñidas con Nissl obtenidas de ratas expuestas al citalopram neonatal (CTM) (5 mg / kg, dos veces al día, sc), desde el día postnatal 8 a 21 (PN8-21), solución salina y ratas no expuestas. La densidad de células piramidales se incrementó significativamente en un 10,2 % en CA1, 10,6 % en CA3 y 13,2 % en CA4 en CTM tratados en comparación con animales no tratados o tratados con solución salina (p <0,0001). La densidad de células granulares en el giro dentado aumentó significativamente en un 12,0 % en los animales tratados con CTM en comparación con los animales no tratados o tratados con solución salina (p <0,0001). Estos hallazgos se obtuvieron solo en ratas macho, lo que sugiere un dimorfismo sexual en el desarrollo neural después de la exposición a ISRS. Estos datos sugieren que la exposición neonatal a la CTM puede inducir cambios de larga duración en la formación del hipocampo en adultos, y estos efectos parecen dirigirse preferentemente a los machos.


Assuntos
Animais , Masculino , Feminino , Gravidez , Ratos , Efeitos Tardios da Exposição Pré-Natal , Citalopram/farmacologia , Hipocampo/efeitos dos fármacos , Antidepressivos/farmacologia , Transtorno Autístico/induzido quimicamente , Comportamento Animal/efeitos dos fármacos , Citalopram/efeitos adversos , Contagem de Células , Fatores Sexuais , Ratos Sprague-Dawley , Células Piramidais/efeitos dos fármacos , Hipocampo/citologia , Hipocampo/crescimento & desenvolvimento , Animais Recém-Nascidos , Antidepressivos/efeitos adversos
15.
Nat Commun ; 10(1): 2637, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31201332

RESUMO

The brain stores and recalls memories through a set of neurons, termed engram cells. However, it is unclear how these cells are organized to constitute a corresponding memory trace. We established a unique imaging system that combines Ca2+ imaging and engram identification to extract the characteristics of engram activity by visualizing and discriminating between engram and non-engram cells. Here, we show that engram cells detected in the hippocampus display higher repetitive activity than non-engram cells during novel context learning. The total activity pattern of the engram cells during learning is stable across post-learning memory processing. Within a single engram population, we detected several sub-ensembles composed of neurons collectively activated during learning. Some sub-ensembles preferentially reappear during post-learning sleep, and these replayed sub-ensembles are more likely to be reactivated during retrieval. These results indicate that sub-ensembles represent distinct pieces of information, which are then orchestrated to constitute an entire memory.


Assuntos
Hipocampo/fisiologia , Memória/fisiologia , Neurônios/fisiologia , Animais , Mapeamento Encefálico/métodos , Feminino , Hipocampo/citologia , Microscopia Intravital/métodos , Proteínas Luminescentes/química , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Camundongos Transgênicos , Microscopia de Fluorescência/métodos , Modelos Animais , Imagem Óptica/métodos , Optogenética/métodos , Sono/fisiologia
16.
Nat Commun ; 10(1): 2693, 2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31217419

RESUMO

The kinesin-3 KIF1C is a fast organelle transporter implicated in the transport of dense core vesicles in neurons and the delivery of integrins to cell adhesions. Here we report the mechanisms of autoinhibition and release that control the activity of KIF1C. We show that the microtubule binding surface of KIF1C motor domain interacts with its stalk and that these autoinhibitory interactions are released upon binding of protein tyrosine phosphatase PTPN21. The FERM domain of PTPN21 stimulates dense core vesicle transport in primary hippocampal neurons and rescues integrin trafficking in KIF1C-depleted cells. In vitro, human full-length KIF1C is a processive, plus-end directed motor. Its landing rate onto microtubules increases in the presence of either PTPN21 FERM domain or the cargo adapter Hook3 that binds the same region of KIF1C tail. This autoinhibition release mechanism allows cargo-activated transport and might enable motors to participate in bidirectional cargo transport without undertaking a tug-of-war.


Assuntos
Cinesina/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Animais , Transporte Biológico , Linhagem Celular , Vesículas Citoplasmáticas/metabolismo , Hipocampo/citologia , Humanos , Integrinas/metabolismo , Microscopia Intravital/métodos , Cinesina/genética , Cinesina/isolamento & purificação , Camundongos , Proteínas Associadas aos Microtúbulos/isolamento & purificação , Microtúbulos/metabolismo , Neurônios/citologia , Cultura Primária de Células , Ligação Proteica , Domínios Proteicos , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas Tirosina Fosfatases não Receptoras/isolamento & purificação , RNA Interferente Pequeno/metabolismo , Ratos , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Imagem Individual de Molécula/métodos
17.
Neuron ; 103(4): 673-685.e5, 2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31230762

RESUMO

Autism spectrum disorder (ASD) is strongly associated with de novo gene mutations. One of the most commonly affected genes is SCN2A. ASD-associated SCN2A mutations impair the encoded protein NaV1.2, a sodium channel important for action potential initiation and propagation in developing excitatory cortical neurons. The link between an axonal sodium channel and ASD, a disorder typically attributed to synaptic or transcriptional dysfunction, is unclear. Here we show that NaV1.2 is unexpectedly critical for dendritic excitability and synaptic function in mature pyramidal neurons in addition to regulating early developmental axonal excitability. NaV1.2 loss reduced action potential backpropagation into dendrites, impairing synaptic plasticity and synaptic strength, even when NaV1.2 expression was disrupted in a cell-autonomous fashion late in development. These results reveal a novel dendritic function for NaV1.2, providing insight into cellular mechanisms probably underlying circuit and behavioral dysfunction in ASD.


Assuntos
Transtorno do Espectro Autista/genética , Dendritos/fisiologia , Córtex Pré-Frontal/fisiologia , Células Piramidais/fisiologia , Potenciais de Ação , Animais , Sinalização do Cálcio , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Heterozigoto , Hipocampo/citologia , Hipocampo/crescimento & desenvolvimento , Hipocampo/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Potenciais Pós-Sinápticos em Miniatura/fisiologia , N-Metilaspartato/análise , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Neocórtex/fisiologia , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/crescimento & desenvolvimento , Engenharia de Proteínas , Comportamento Social , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/análise
18.
Sheng Li Xue Bao ; 71(3): 431-438, 2019 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-31218334

RESUMO

The present study was aimed to investigate the effects and mechanisms of electro-acupuncture (EA) on proliferation and differentiation of neural stem cells in the hippocampus of C57 mice exposed to different doses of X-ray radiation. Thirty-day-old C57BL/6J mice were randomly divided into control, irradiation, and EA groups. The control group was not treated with irradiation. The irradiation groups were exposed to different doses of X-ray (4, 8 or 16 Gy) for 10 min. The EA groups were electro-acupunctured at Baihui, Fengfu and bilateral Shenyu for 3 courses of treatment after X-ray radiation. Immunohistochemistry was used to evaluate proliferation and differentiation of the hippocampal neural stem cell. RT-PCR and Western blot were used to detect mRNA and protein expressions of Notch1 and Mash1 in the hippocampus, respectively. The results showed that, compared with the control group, the numbers of BrdU positive cells (4, 8 Gy subgroup) and BrdU/NeuN double-labeling positive cells (3 dose subgroups) were decreased significantly in the irradiation group, but the above changes could be reversed by EA. Compared with the control group, the number of BrdU/GFAP double-labeling positive cells in each dose subgroup of irradiation group was decreased significantly, while EA could reverse the change of 4 and 8 Gy dose subgroups. In addition, compared with the control group, the expression levels of Notch1 mRNA and protein in hippocampus were up-regulated, and the expression levels of Mash1 mRNA and protein were significantly decreased in each dose subgroup of irradiation group. Compared with irradiation group, the expression levels of Notch1 mRNA and protein in hippocampus of EA group were decreased significantly in each dose subgroup, and the expression levels of Mash1 mRNA and protein were increased significantly in 4 and 8 Gy subgroups. These results suggest that irradiation affects the proliferation and differentiation of neural stem cells in hippocampus of mice, whereas EA may significantly increase the proliferation and differentiation of hippocampal neural stem cells via the regulation of Notch signaling pathway.


Assuntos
Diferenciação Celular , Proliferação de Células , Eletroacupuntura , Células-Tronco Neurais/citologia , Raios X/efeitos adversos , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Hipocampo/citologia , Hipocampo/efeitos da radiação , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/efeitos da radiação , Distribuição Aleatória , Receptor Notch1/metabolismo
19.
Nat Neurosci ; 22(7): 1061-1065, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31209378

RESUMO

A key assumption of optogenetics is that light only affects opsin-expressing neurons. However, illumination invariably heats tissue, and many physiological processes are temperature-sensitive. Commonly used illumination protocols increased the temperature by 0.2-2 °C and suppressed spiking in multiple brain regions. In the striatum, light delivery activated an inwardly rectifying potassium conductance and biased rotational behavior. Thus, careful consideration of light-delivery parameters is required, as even modest intracranial heating can confound interpretation of optogenetic experiments.


Assuntos
Córtex Cerebral/fisiologia , Corpo Estriado/fisiologia , Hipocampo/fisiologia , Neurônios/fisiologia , Temperatura Ambiente , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/efeitos da radiação , Animais , Compostos de Bário/farmacologia , Córtex Cerebral/citologia , Cloretos/farmacologia , Corpo Estriado/citologia , Hipocampo/citologia , Temperatura Alta , Transporte de Íons/efeitos dos fármacos , Transporte de Íons/efeitos da radiação , Luz , Camundongos , Atividade Motora/efeitos da radiação , Neurônios/efeitos dos fármacos , Neurônios/efeitos da radiação , Optogenética/métodos , Técnicas de Patch-Clamp , Potássio/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/efeitos dos fármacos , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/efeitos da radiação , Projetos de Pesquisa
20.
Int J Mol Sci ; 20(11)2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31151322

RESUMO

Oxidative stress is believed to be one of the main causes of neurodegenerative diseases such as Alzheimer's disease (AD). The pathogenesis of AD is still not elucidated clearly but oxidative stress is one of the key hypotheses. Here, we found that artemisinin, an anti-malarial Chinese medicine, possesses neuroprotective effects. However, the antioxidative effects of artemisinin remain to be explored. In this study, we found that artemisinin rescued SH-SY5Y and hippocampal neuronal cells from hydrogen peroxide (H2O2)-induced cell death at clinically relevant doses in a concentration-dependent manner. Further studies showed that artemisinin significantly restored the nuclear morphology, improved the abnormal changes in intracellular reactive oxygen species (ROS), reduced the mitochondrial membrane potential, and caspase-3 activation, thereby attenuating apoptosis. Artemisinin also stimulated the phosphorylation of the adenosine monophosphate -activated protein kinase (AMPK) pathway in SH-SY5Y cells in a time- and concentration-dependent manner. Inhibition of the AMPK pathway attenuated the protective effect of artemisinin. These data put together suggested that artemisinin has the potential to protect neuronal cells. Similar results were obtained in primary cultured hippocampal neurons. Cumulatively, these results indicated that artemisinin protected neuronal cells from oxidative damage, at least in part through the activation of AMPK. Our findings support the role of artemisinin as a potential therapeutic agent for neurodegenerative diseases.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Artemisininas/farmacologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Antimaláricos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Células Cultivadas , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Neurônios/citologia , Neurônios/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
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