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Neuroscience Bulletin ; (6): 1645-1657, 2021.
Article in English | WPRIM | ID: wpr-922643


Steroid hormones play important roles in brain development and function. The signaling of steroid hormones depends on the interaction between steroid receptors and their coactivators. Although the function of steroid receptor coactivators has been extensively studied in other tissues, their functions in the central nervous system are less well investigated. In this study, we addressed the function of steroid receptor coactivator 3 (SRC3) - a member of the p160 SRC protein family that is expressed predominantly in the hippocampus. While hippocampal development was not altered in Src3

Animals , Hippocampus , Long-Term Potentiation , Mice , Neuronal Plasticity , Nuclear Receptor Coactivator 3/genetics , Synapses
Article in English | WPRIM | ID: wpr-922255


The N-methyl-D-aspartate receptor (NMDAR) in central nerve system is mostly composed of GluN1 and GluN2 subunits. The classical NMDAR has been intensively studied. However, GluN3‑containing NMDAR is much less expressed and have atypical channel properties. Recently, accumulating evidences have revealed two types of GluN3‑containing NMDAR: glutamate-gated GluN1/GluN2/GluN3 NMDAR and glycine-gated GluN1/GluN3 NMDAR. The former may play important roles in regulating synapse maturation and pruning non-used synapses, and its elevated expression at the adult stage may alter synaptic reorganization in some neuropsychiatric disorders. The latter is expressed in the medial habenula and involves in control of aversion. This article reviews the recent progresses on the expression, functional properties of GluN3‑containing atypical NMDARs and the physiological and pathological relevance.

Central Nervous System/metabolism , Protein Subunits/metabolism , Receptors, N-Methyl-D-Aspartate , Synapses
Article in Chinese | WPRIM | ID: wpr-879023


To explore the effect of Baihe Dihuang Decoction on the synaptic plasticity of hippocampal neurons in rats with anxious depression. Fifty SD rats were randomly divided into normal group, model group, venlafaxine group(6.75 mg·kg~(-1)), high-dose Baihe Dihuang Decoction group(8.64 g·kg~(-1)) and low-dose Baihe Dihuang Decoction group(4.32 g·kg~(-1)). Chronic restraint stress(6 h) combined with corticosterone(ih, 30 mg·kg~(-1)) was used to establish an anxious depression model, and 7 days after modeling, the administration started and continued for 21 days. The anxiety and depression-like behaviors of the rats were evaluated. Golgi-Cox staining and electron microscopy were used to observe the morphology and ultrastructural changes of synaptic dendrites. Immunofluorescence was used to detect the expression of hippocampal synaptic plasticity protein synapsin-1 and postsynaptic density protein 95(PSD-95). Western blot method was used to detect the expression of functional protein synaptophysin(SYP) and synaptic Ras GTPase activating protein(SynGap). The results showed that the rats in the model group had obvious anxiety and depression-like behaviors, the hip-pocampal dendritic spine density and branch length were reduced, the number of synapses was cut, and the internal structure was da-maged. The average fluorescence intensity of synapsin-1 and PSD-95 was significantly reduced and the expression of SYP and SynGap also decreased. High-dose Baihe Dihuang Decoction could significantly improve the anxiety and depression-like behaviors of model rats, relieve synaptic damage, and increase the expression of synapsin-1, PSD-95, SYP, and SynGap proteins. Therefore, we believe that Baihe Dihuang Decoction can improve anxiety and depression behaviors by regulating the synaptic plasticity of hippocampal neurons.

Animals , Depression/drug therapy , Hippocampus , Neuronal Plasticity , Rats , Rats, Sprague-Dawley , Synapses
Med. U.P.B ; 39(2): 49-55, 21/10/2020.
Article in Spanish | LILACS, COLNAL | ID: biblio-1123581


La aparición progresiva de habilidades sensoriales, motoras y cognitivo-afectivas en el humano a lo largo de su desarrollo es un reflejo de cambios fisiológicos que se gestan al interior del sistema nervioso. Dichos cambios hacen parte de procesos dinámicos y dependen, después del nacimiento, de la actividad eléctrica inducida por la experiencia. Considerando lo anterior, el sistema nervioso en desarrollo constituye una especie de protomapa, sobre el que la experiencia moldea características moleculares, neuroquímicas y de conectividad, que se reflejan en las actividades emergentes del sistema. La evidencia que soporta la importancia que la influencia experiencial tiene sobre el desarrollo del sistema nervioso viene en aumento. Esta revisión reúne información sobre estudios en modelos biológicos y en humanos sometidos a privación sensorial y ambiental. Se enfatiza en la caracterización de los rasgos cognitivos y sociales.

The progressive advent of sensory, motor, affective, and cognitive skills in the human being through its development, demonstrate physiological changes that are gestated within the nervous system. These processes are dynamic and dependent postnatally on electrical activity induced by experience. Taking this into account, the developing nervous system constitutes a protomap molded by experience dependent molecular, physiological and connectivity characteristics, which are reflected in the emergent principles of the system. The evidence that supports the importance of experience as influence over the development of this system has increased in the past years. This document gathers information about animal models and human studies enduring sensory and environmental deprivation, emphasizing in the characterization of their cognitive and social remarks.

O aparecimento progressivo de habilidades sensoriais, motoras e cognitivo-afetivas no humano ao longo do seu desenvolvimento é um reflexo de mudanças fisiológicas que se gestam no interior do sistema nervoso. Ditas mudanças fazem parte de processos dinâmicos e dependem, depois do nascimento, da atividade elétrica induzida pela experiência. Considerando o anterior, o sistema nervoso em desenvolvimento constitui uma espécie de "protomapa", sobre o que a experiência molda características moleculares, neuroquímicas e de conectividade, que se refletem nas atividades emergentes do sistema. A evidência que suporta a importância que a influência experiencial tem sobre o desenvolvimento do sistema nervoso vem em aumento. Esta revisão reúne informação sobre estudos em modelos biológicos e em humanos submetidos a privação sensorial e ambiental. Se enfatiza na caracterização das características cognitivas e sociais.

Humans , Animals , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Neurodevelopmental Disorders , Reflex , Sensory Deprivation , Synapses , Cognition , Models, Animal , Growth and Development , Models, Biological , Nervous System , Neuronal Plasticity
Acta Physiologica Sinica ; (6): 220-226, 2020.
Article in Chinese | WPRIM | ID: wpr-827066


Synaptic cell adhesion molecules (CAMs) are a type of membrane surface glycoproteins that mediate the structural and functional interactions between pre- and post-synaptic sites. Synaptic CAMs dynamically regulate synaptic activity and plasticity, and their expression and function are modulated by environmental factors. Synaptic CAMs are also important effector molecules of stress response, and mediate the adverse impact of stress on cognition and emotion. In this review, we will summarize the recent progress on the role of synaptic CAMs in stress, and aim to provide insight into the molecular mechanisms and drug development of stress-related disorders.

Cell Adhesion , Cell Adhesion Molecules , Physiology , Humans , Neuronal Plasticity , Stress, Physiological , Stress, Psychological , Synapses
Article in Chinese | WPRIM | ID: wpr-781308


OBJECTIVE@#To explore susceptibility genes for autism spectrum disorders (ASD).@*METHODS@#Whole-exome sequencing was carried out for 60 family trios affected with sporadic ASD. Genetic variants discovered in over 10% of the patients were selected for genotype-phenotype correlation and pathway enrichment analysis using Phenolyzer software and metascape database. Combining gene-phenotypic scores, pathway-related genes associated with neural and neurite triggering were screened for the candidates.@*RESULTS@#A total of 170 common variants were found to be associated with the ASD phenotype. Among these, there was only one high-confidence gene [SHANK2(0.8146)] and four medium-confidence genes [ERBB2(0.1322), LAMC3(0.1117), PPFIA4(0.1059), DISC1(0.1002)]. Twenty-pathways and four biological processes were found to be statistically significant by pathway enrichment analysis, which included neuron projection morphogenesis (GO: 0048812), regulation of neuroblast proliferation (GO: 1902692), modulation of excitatory postsynaptic potential (GO: 0098815), and dendrite morphogenesis (GO: 0048813). Twenty-one genes were found to be closely associated with neurological and neurite triggering, among which only SHANK2, ERBB2, and DISC1 had above-medium confidence correlation scores with the ASD phenotypes.@*CONCLUSION@#Abnormal neuron projection morphogenesis (GO: 0048812) may be closely related to the occurrence of ASD. SHANK2, ERBB2, and DISC1 are susceptibility genes for ASD.

Autism Spectrum Disorder , Genetics , Genetic Predisposition to Disease , Genetic Variation , Humans , Phenotype , Synapses , Genetics , Whole Exome Sequencing
Rev. chil. neuropsicol. (En línea) ; 14(1): 30-35, ago. 2019.
Article in Spanish | LILACS | ID: biblio-1102090


El objetivo de este artículo de revisión es dar a conocer diferentes perspectivas que han contribuido al estudio del Código Neuronal, un concepto que proviene de la Neurociencia y que explica el funcionamiento del cerebro a través de conexiones de neuronas. Se entregan cuatro ideas relacionadas con el análisis de este funcionamiento. En primer lugar, la propuesta de Convergencia Jerárquica, que ofrece una explicación asociada a un correlato neuronal específico para una conducta determinada. En segundo lugar, se aborda la idea del Código de Poblaciones, que explica el trabajo de un grupo de neuronas que representan un determinado estado. Posteriormente se expone la propuesta de Correlación Temporal, que plantea la presencia de poblaciones neuronales activas que se diferencian entre sí en base a patrones temporales de descarga para, finalmente, llegar al concepto de redes neuronales y sus diferentes modelos explicativos que han actuado como cimientos para el desarrollo de la Neurociencia moderna y que han sido desarrollados gracias a los aportes de la Biología, la Física, las Matemáticas, entre otras disciplinas, y que han generado las bases para la comprensión del funcionamiento del cerebro a través de neuronas interconectadas para lograr la expresión de los diferentes procesos cognitivos. El presente artículo pretende que el lector desarrolle una visión panorámica y general de cómo opera el flujo de la información que procesa el sistema nervioso central y el impacto que este fenómeno genera en el proceso de integración sensorial como parte de la emoción y la cognición en el cerebro humano.

The objective of this review article is to present different perspectives that have contributed to the study of the Neural Code, a concept that comes from Neuroscience and that explains the functioning of the brain through neuron connections. Four ideas related to the analysis of this functioning are presented. Firstly, the proposal of Hierarchical Convergence, which offers an explanation associated with a specific neuronal correlate for a specific behavior. Secondly, the idea of the Population Code is discussed, which explains the work of a group of neurons that represent a certain state. Subsequently, the proposal of Temporal Correlation is addressed, which proposes the presence of active neuronal populations that differentiate each other based on temporal discharge patterns, finally arriving at the concept of neural networks and their different explanatory models. The latter have acted as foundations for the development of modern Neuroscience and have been developed thanks to the contributions of Biology, Physics, Mathematics, among other disciplines, and have generated the basis for understanding the functioning of the brain through interconnected neurons to achieve the expression of the different cognitive processes. The paper aims to develop a panoramic and general view of how the flow of information processed by the central nervous system operates and the impact that this phenomenon generates in the process of sensory integration as part of emotion and cognition in the human brain.

Humans , Neurons/physiology , Synapses , Neurosciences , Cognition
Medicina (B.Aires) ; 79(1,supl.1): 27-32, abr. 2019. ilus, tab
Article in Spanish | LILACS | ID: biblio-1002601


Los trastornos del espectro autista (TEA) son una alteración funcional de la corteza cerebral, que presenta anomalías estructurales del neurodesarrollo que afectan fundamentalmente a la función sináptica y el patrón de conexiones dentro y entre columnas corticales. Desde su aspecto etiológico, el TEA tiene una importante carga genética, considerándose un desorden derivado de una combinación de mutaciones "de novo", asociadas a una predisposición derivada de variaciones comunes heredadas. Las principales anomalías genéticas asociadas a TEA implican genes que codifican proteínas de la sinapsis. Así, en pacientes con TEA se han descrito alteraciones del desarrollo inicial de las sinapsis en los circuitos de conexión entre áreas corticales de procesamiento complejo. La complejidad molecular observada en la predisposición a desarrollar un TEA, junto con la diversidad de fenotipos estructurales neuronales, ha hecho que los modelos animales reproduzcan solo parcialmente el TEA. Para avanzar en el estudio experimental se hace pues necesario desarrollar modelos más representativos, como son los modelos celulares derivados de células humanas. En las últimas décadas, el desarrollo de la biología de las células madre nos da medios para acceder a paradigmas experimentales sobre células derivadas de individuos con TEA. Actualmente, los modelos de células plutipotentes inducidas (IPs) derivadas de células humanas permiten profundizar en el estudio de las bases moleculares y celulares del TEA. Sin embargo, presentan problemas inherentes derivados de la manipulación experimental que conlleva la reprogramación de la expresión génica, por lo que otros modelos celulares se están también postulando como válidos.

Autism Spectrum Disorders (ASD) are a functional alteration of the cerebral cortex, which presents structural neurodevelopmental anomalies that affect synaptic function and the pattern of connections within and between cortical columns. From its etiological aspect, ASD has an important genetic load, considering a polygenic disorder, derived from a combination of "de novo" genetic mutations, associated to a predisposition derived from common inherited variations. The main genetic anomalies associated with ASD involve genes that encode proteins of the synapse. Thus, in patients with ASD, alterations in the initial development of the synapses have been described in the connection circuits between complex processing cortical areas. The molecular complexity observed in the predisposition to develop an ASD, together with the diversity of structural phenotypes, has made animal models reproduce only partially the ASD. To advance in the experimental study it is therefore necessary to develop representative models, such as cellular models derived from human cells. In recent decades, the advances in stem cell biology give us a way to apply experimental paradigms in cells derived from individuals with ASD. Currently, induced pluripotent cells (IPs) derived from human adult cells allow deepening the study of molecular and cellular bases of the neuronal development in humans, as well as the anomalies in this development, which give rise to disorders such as ASD. However, they present inherent problems derived from the experimental manipulation that involves the reprogramming of gene expression, therefore other models are also been explored.

Humans , Autism Spectrum Disorder/physiopathology , Models, Biological , Synapses/physiology , Synapses/genetics , Gene Expression , Genetic Predisposition to Disease/genetics , Epigenesis, Genetic/genetics , Induced Pluripotent Stem Cells/cytology , Neurodevelopmental Disorders/physiopathology , Autism Spectrum Disorder/genetics
Experimental Neurobiology ; : 451-457, 2019.
Article in English | WPRIM | ID: wpr-763782


Currently, compared to jaw-closing (JC) α-motoneurons, the information on the distribution and morphology of glutamatergic synapses on the jaw-closing (JC) γ-motoneurons, which may help elucidate the mechanism of isometric contraction of the JC muscle, is very limited. This study investigated the distribution and ultrastructural features of vesicular glutamate transporter 1 (VGLUT1)- and VGLUT2-immunopositive (+) axon terminals (boutons) on JC γ-motoneurons by retrograde tracing with horseradish peroxidase, electron microscopic immunocytochemistry, and quantitative analysis. About 35% of the boutons on identified JC γ-motoneurons were VGLUT+, and of those, 99% were VGLUT2+. The fraction of VGLUT1+ boutons of all boutons and the percentage of membrane of JC γ-motoneurons covered by these boutons were significantly lower than those for the JC α-motoneurons, revealed in our previous work. The bouton volume, mitochondrial volume, and active zone area of the VGLUT2+ boutons on the JC γ-motoneurons were uniformly small. These findings suggest that the JC γ-motoneurons, in contrast to the JC α-motoneurons, receive generally weak glutamatergic synaptic input almost exclusively from VGLUT2+ premotoneurons that form direct synapse with motoneurons.

Animals , Horseradish Peroxidase , Immunohistochemistry , Isometric Contraction , Membranes , Microscopy, Electron , Mitochondrial Size , Motor Neurons , Presynaptic Terminals , Rats , Synapses , Vesicular Glutamate Transport Protein 1
Experimental Neurobiology ; : 320-328, 2019.
Article in English | WPRIM | ID: wpr-763772


The basolateral amygdala (BLA) receives dense projections from cholinergic neurons of the basal forebrain. Acetylcholine can contributes to amygdala-dependent behaviors: formation and extinction of fear memory and appetitive instrumental learning. However, the cholinergic mechanism at the circuit level has not been defined yet. We demonstrated that cholinergic-induced di-synaptic inhibition of BLA pyramidal neurons exhibits a retrograde form of short-term synaptic inhibition, depolarization-induced suppression of inhibition (DSI). Activation of nicotinic receptors was sufficient to evoke action potentials in cholecystokinin (CCK)-positive inhibitory neurons, which strongly inhibit pyramidal neurons through their perisomatic synapses. Our cell type-specific monosynaptic retrograde tracing also revealed that CCK neurons are innervated by basal forebrain cholinergic neurons. Therefore, our data indicated that CCK inhibitory neurons mediate the cholinergic-induced di-synaptic inhibition of BLA pyramidal neurons.

Acetylcholine , Action Potentials , Basal Forebrain , Basolateral Nuclear Complex , Cholecystokinin , Cholinergic Neurons , Conditioning, Operant , Iontophoresis , Memory , Neurons , Pyramidal Cells , Receptors, Nicotinic , Synapses
Article in English | WPRIM | ID: wpr-761804


It is known that top-down associative inputs terminate on distal apical dendrites in layer 1 while bottom-up sensory inputs terminate on perisomatic dendrites of layer 2/3 pyramidal neurons (L2/3 PyNs) in primary sensory cortex. Since studies on synaptic transmission in layer 1 are sparse, we investigated the basic properties and cholinergic modulation of synaptic transmission in layer 1 and compared them to those in perisomatic dendrites of L2/3 PyNs of rat primary visual cortex. Using extracellular stimulations of layer 1 and layer 4, we evoked excitatory postsynaptic current/potential in synapses in distal apical dendrites (L1-EPSC/L1-EPSP) and those in perisomatic dendrites (L4-EPSC/L4-EPSP), respectively. Kinetics of L1-EPSC was slower than that of L4-EPSC. L1-EPSC showed presynaptic depression while L4-EPSC was facilitating. In contrast, inhibitory postsynaptic currents showed similar paired-pulse ratio between layer 1 and layer 4 stimulations with depression only at 100 Hz. Cholinergic stimulation induced presynaptic depression by activating muscarinic receptors in excitatory and inhibitory synapses to similar extents in both inputs. However, nicotinic stimulation enhanced excitatory synaptic transmission by ~20% in L4-EPSC. Rectification index of AMPA receptors and AMPA/NMDA ratio were similar between synapses in distal apical and perisomatic dendrites. These results provide basic properties and cholinergic modulation of synaptic transmission between distal apical and perisomatic dendrites in L2/3 PyNs of the visual cortex, which might be important for controlling information processing balance depending on attentional state.

Animals , Electronic Data Processing , Dendrites , Depression , Inhibitory Postsynaptic Potentials , Kinetics , Pyramidal Cells , Rats , Receptors, AMPA , Receptors, Muscarinic , Synapses , Synaptic Transmission , Visual Cortex
Article in English | WPRIM | ID: wpr-761304


OBJECTIVES: Restorative Dentistry and Endodontics (Restor Dent Endod; RDE) is an English-language journal published by the Korean Academy of Conservative Dentistry, and it has been online since 2012 with quarterly publications. The purpose of this paper was to review and analyze the publications in this journal since its inception and over the 7-year period from 2012 to 2018. MATERIALS AND METHODS: This paper assessed the number, type, and subject of articles published, as well as authorship patterns and article citations of the journal over a 7-year period. The citation indicator for the journal (h-index) was assessed using Google Scholar. RESULTS: The number of articles per issue has remained relatively consistent in the 7 years that were analyzed. An analysis of the article types revealed various categories of review articles. Original research articles accounted for the most articles per volume. Twice as many articles per volume were on endodontic topics than on restorative subjects. Articles published in RDE have been widely cited in Synapse, Crossref, and PubMed Central. A country-wise mapping of authors' institutions revealed significant contributions from authors around the world. With an h-index of 24, RDE ranks third among journals in its specialty. The most cited articles were open lectures on statistics and research articles on recent concepts, technology, and materials. CONCLUSION: Over the last 7 years, RDE has served as a platform for a large number of manuscripts in the field of restorative dentistry and endodontics.

Authorship , Bibliometrics , Dentistry , Endodontics , Lecture , Phytolacca dodecandra , Publications , Synapses
Article in English | WPRIM | ID: wpr-762697


PURPOSE: Complete removal of the caudate lobe, which is sometimes necessary, is accomplished via isolated caudate lobectomy or hepatectomy that includes the caudate lobe. It is impossible, however, to confirm the right and ventral margins of the caudate lobe by preoperative imaging. This study was undertaken to determine whether we could identify the right and ventral margins of the caudate lobe preoperatively using Synapse 3D visualization software. METHODS: Ninety-four preoperative 3-dimensional (3D) computed tomographic images (1-mm slices) of the liver from candidate donors were examined. The images of the caudate lobe were subjected to a counter-staining method according to Synapse 3D to delineate their dimensions. We first examined whether the right margin of the caudate lobe exceeded the plane formed by the root of the right hepatic vein (RHV) and the right side of the inferior vena cava (IVC). Second, we determined whether the ventral margin of the caudate lobe exceeded the plane formed by the root of the middle hepatic vein (MHV) and the root of the RHV. RESULTS: For the right margin, 17 cases (18%) exceeded the RHV-IVC plane by a mean of 10.2 mm (range, 2.4–27.2 mm). For the ventral margin, 28 cases (30%) exceeded the MHV-RHV plane by a mean of 17.4 mm (range, 1.2–49.1 mm). CONCLUSION: Evaluating the anatomy of caudate lobe using Synapse 3D preoperatively could be helpful for more precise anatomical resection of the caudate lobe.

Hepatectomy , Hepatic Veins , Humans , Imaging, Three-Dimensional , Liver , Methods , Synapses , Tissue Donors , Vena Cava, Inferior
Neuroscience Bulletin ; (6): 497-506, 2019.
Article in English | WPRIM | ID: wpr-775419


Neuroligins (NLs) are postsynaptic cell-adhesion proteins that play important roles in synapse formation and the excitatory-inhibitory balance. They have been associated with autism in both human genetic and animal model studies, and affect synaptic connections and synaptic plasticity in several brain regions. Yet current research mainly focuses on pyramidal neurons, while the function of NLs in interneurons remains to be understood. To explore the functional difference among NLs in the subtype-specific synapse formation of both pyramidal neurons and interneurons, we performed viral-mediated shRNA knockdown of NLs in cultured rat cortical neurons and examined the synapses in the two major types of neurons. Our results showed that in both types of neurons, NL1 and NL3 were involved in excitatory synapse formation, and NL2 in GABAergic synapse formation. Interestingly, NL1 affected GABAergic synapse formation more specifically than NL3, and NL2 affected excitatory synapse density preferentially in pyramidal neurons. In summary, our results demonstrated that different NLs play distinct roles in regulating the development and balance of excitatory and inhibitory synapses in pyramidal neurons and interneurons.

Animals , Cell Adhesion Molecules, Neuronal , Physiology , Cells, Cultured , Cerebral Cortex , Embryology , Physiology , GABAergic Neurons , Physiology , Interneurons , Physiology , Membrane Proteins , Physiology , Nerve Tissue Proteins , Physiology , Protein Isoforms , Physiology , Pyramidal Cells , Physiology , Rats, Sprague-Dawley , Synapses , Physiology
Experimental Neurobiology ; : 85-103, 2019.
Article in English | WPRIM | ID: wpr-739528


Cell replacement therapy using neural progenitor cells (NPCs) following ischemic stroke is a promising potential therapeutic strategy, but lacks efficacy for human central nervous system (CNS) therapeutics. In a previous in vitro study, we reported that the overexpression of human arginine decarboxylase (ADC) genes by a retroviral plasmid vector promoted the neuronal differentiation of mouse NPCs. In the present study, we focused on the cellular mechanism underlying cell proliferation and differentiation following ischemic injury, and the therapeutic feasibility of NPCs overexpressing ADC genes (ADC-NPCs) following ischemic stroke. To mimic cerebral ischemia in vitro , we subjected the NPCs to oxygen-glucose deprivation (OGD). The overexpressing ADC-NPCs were differentiated by neural lineage, which was related to excessive intracellular calcium-mediated cell cycle arrest and phosphorylation in the ERK1/2, CREB, and STAT1 signaling cascade following ischemic injury. Moreover, the ADC-NPCs were able to resist mitochondrial membrane potential collapse in the increasingly excessive intracellular calcium environment. Subsequently, transplanted ADC-NPCs suppressed infarct volume, and promoted neural differentiation, synapse formation, and motor behavior performance in an in vivo tMCAO rat model. The results suggest that ADC-NPCs are potentially useful for cell replacement therapy following ischemic stroke.

Animals , Arginine , Brain Ischemia , Calcium , Cell Cycle Checkpoints , Cell Proliferation , Central Nervous System , Humans , In Vitro Techniques , Membrane Potential, Mitochondrial , Mice , Models, Animal , Neurons , Phosphorylation , Plasmids , Stem Cells , Stroke , Synapses , Zidovudine
Article in Chinese | WPRIM | ID: wpr-781848


Biological neural networks have dual properties of small-world attributes and scale-free attributes. Most of the current researches on neural networks are based on small-world networks or scale-free networks with lower clustering coefficient, however, the real brain network is a scale-free network with small-world attributes. In this paper, a scale-free spiking neural network with high clustering coefficient and small-world attribute was constructed. The dynamic evolution process was analyzed from three aspects: synaptic regulation process, firing characteristics and complex network characteristics. The experimental results show that, as time goes by, the synaptic strength gradually decreases and tends to be stable. As a result, the connection strength of the network decreases and tends to be stable; the firing rate of neurons gradually decreases and tends to be stable, and the synchronization becomes worse; the local information transmission efficiency is stable, the global information transmission efficiency is reduced and tends to be stable, and the small-world attributes are relatively stable. The dynamic characteristics vary with time and interact with each other. The regulation of synapses is based on the firing time of neurons, and the regulation of synapses will affect the firing of neurons and complex characteristics of networks. In this paper, a scale-free spiking neural network was constructed, which has biological authenticity. It lays a foundation for the research of artificial neural network and its engineering application.

Action Potentials , Models, Neurological , Neural Networks, Computer , Neuronal Plasticity , Synapses
Acta Physiologica Sinica ; (6): 471-477, 2019.
Article in Chinese | WPRIM | ID: wpr-777166


The C1q family is one of the subcomponents of the C1 complex that recognizes immune complexes and initiates the classical pathway of the complement system. In addition, as a pattern recognition receptor (PRR), the C1q family binds to a wide variety of ligands. As a member of the C1q family, the secretory C1q includes several subtypes. The main subtypes are cerebellin (Cbln) and C1q-like protein (C1ql). In the nervous system, secretory C1q is involved in the formation and regulation of various types of synapses, thus secretory C1q is closely related to diseases of the central nervous system. In this article, we review the role of secretory C1q in synapse formation and regulation, and its relationship with some diseases of the central nervous system.

Antigen-Antibody Complex , Central Nervous System , Complement C1q , Physiology , Humans , Synapses , Physiology
Int. j. morphol ; 37(1): 28-35, 2019. tab, graf
Article in English | LILACS | ID: biblio-990000


SUMMARY: There is an increasing amount of evidence that supports the diabetic complications of the central nervous system structure and function. The cerebellum, which is one of the primary structure derived from the hindbrain, plays an important role in motor control, motor coordination, and non-motor functions, such as cognitive processing. The synapse is a critical structure that regulates neuronal communication, and well-defined afferent and efferent fibre connections in the cerebellum help in maintaining the proper working order. Thus, the present study sought to investigate the long-term effects of diabetes-induced synaptopathy in the cerebellum, using both histological and ultrastructural studies. Twenty Sprague-Dawley male rats were divided randomly into control and diabetic groups, and diabetes was then induced through a single intraperitoneal injection of streptozotocin (60 mg/kg body weight). Six month later, the rats were sacrificed and the cerebellum was removed. Light and electron microscopic examinations showed a degeneration of Purkinje cells (Neuron purkinjense) with shrunken cells, pyknotic nuclei, and synaptopathy, including the reduction in synapse density, number of synaptic vesicles, and maturation of synapses in the molecular layer of diabetic cerebellum. The disruptions in synaptic profiles, which observed in the diabetic condition, could be related to cerebellar dysfunction, thus leading to the defects in coordinated movement, balance, as well as cognitive learning and memory.

RESUMEN: Actualmente existe una creciente evidencia que apoya las complicaciones diabéticas de la estructura y función del sistema nervioso central. El cerebelo, una de las estructuras primarias del cerebro posterior, desempeña un papel importante en el control motor, la coordinación motora y las funciones no motoras, tanto como en el procesamiento cognitivo. La sinapsis es una estructura crítica que regula la comunicación neuronal y las conexiones de fibras aferentes y eferentes bien definidas en el cerebelo, ayudan a mantener el funcionamiento correcto. Por lo tanto, en el presente estudio se investigaron los efectos a largo plazo de la sinaptopatía inducida por la diabetes en el cerebelo, utilizando estudios histológicos y ultraestructurales. Veinte ratas SpragueDawley macho se dividieron al azar en grupos de control y diabetes, se indujó la diabetes a través de una inyección intraperitoneal única de estreptozotocina (60 mg / kg de peso corporal). Seis meses después, se sacrificaron las ratas y se extrajo el cerebelo. Los exámenes de microscopías óptica y electrónica mostraron una degeneración de las neuronas purkinjenses (células de Purkinje), con células reducidas, núcleos picnóticos y sinaptopatía, como también la densidad reducida de sinapsis, el número de vesículas sinápticas y la maduración de las sinapsis en la capa molecular del cerebelo de las ratas diabéticas. Las interrupciones en los perfiles sinápticos, que se observaron en la condición diabética, podrían estar relacionadas con la disfunción cerebelosa, lo que lleva a defectos en el movimiento coordinado, el equilibrio, así como al aprendizaje cognitivo y la memoria.

Animals , Male , Rats , Synapses/pathology , Cerebellum/pathology , Diabetes Mellitus, Experimental/pathology , Purkinje Cells/pathology , Weight Loss , Rats, Sprague-Dawley , Glycosuria/pathology , Hyperglycemia/pathology , Microscopy/methods
Rev. chil. neuropsicol. (En línea) ; 13(1): 1-5, ago. 2018.
Article in Spanish | LILACS | ID: biblio-1099481


El objetivo de esta revisión es dar a conocer las diferentes vertientes que sustentan el proceso del aprendizaje en base a un concepto que ha alcanzado una gran importancia en los últimos años, el Ambiente Enriquecido (AE). Un término que ha sido emanado desde la biología, con diversos estudios de laboratorio realizados por científicos de renombre mundial y que, progresivamente ha ido incorporándose a disciplinas como la Psicología y la Pedagogía. En este artículo proponemos la descripción del impacto de este concepto en el proceso de aprendizaje experimentado por los seres humanos y su abordaje desde una perspectiva multidisciplinaria. Comenzamos por describir las bases neurofisiológicas del aprendizaje, con los fundamentos de la teoría neuronal como principal protagonista, pasando por la importancia de la Plasticidad Sináptica (PS) en el proceso de aprendizaje, el fenómeno de la Potenciación a Largo Plazo (PLP), como proceso generador de redes neuronales efectivas y sólidas. Posteriormente abordamos la génesis del Ambiente Enriquecido, con su origen en los experimentos con ratones de laboratorio, para posteriormente describir los conceptos y términos que han emanado del mismo que han sido aplicables a la Psicología Educacional tales como el Ambiente Desafiante, los instrumentos necesarios para su implementación y también el importante rol de las emociones en el proceso de aprendizaje de los sujetos. Finalmente, describimos el rol de la Pedagogía en la aplicación de actividades efectivas que conduzcan a un aprendizaje significativo en base al Ambiente Enriquecido.

The aim of this review is to present different strands that sustain the learning process based on a concept that has reached a major importance in recent years, the Enriched Environment (EE). A term that has been emerged from biology, with various laboratory studies conducted by world-renowned scientists and that has progressively been incorporated into disciplines such as Psychology and Education. In this article, we propose the description of the impact of this concept on the learning process experienced by human beings and its approach from a multidisciplinary perspective. We begin by describing the neurophysiological bases of learning, with the fundamentals of neuronal theory as the main protagonist, passing through the importance of Synaptic Plasticity (SP) in the learning process, the phenomenon of Long Term Potentiation (LTP), as a generating process of effective and solid neural networks. Subsequently, we covered the genesis of the Enriched Environment, with its origin in the experiments with laboratory mice, to later describe the concepts and terms that have emanated from it and have been applicable to Educational Psychology, such as Challenging Environment, the necessary instruments for its implementation and the important role of emotions in the subjects' learning process. Finally, we describe the role of Education in the implementation of effective activities that lead to meaningful learning based on the Enriched Environment.

Humans , Environment , Learning/physiology , Neuronal Plasticity/physiology , Synapses/physiology
Article in English | WPRIM | ID: wpr-715620


Glial cells are receiving much attention since they have been recognized as important regulators of many aspects of brain function and disease. Recent evidence has revealed that two different glial cells, astrocytes and microglia, control synapse elimination under normal and pathological conditions via phagocytosis. Astrocytes use the MEGF10 and MERTK phagocytic pathways, and microglia use the classical complement pathway to recognize and eliminate unwanted synapses. Notably, glial phagocytosis also contributes to the clearance of disease-specific protein aggregates, such as β-amyloid, huntingtin, and α-synuclein. Here we reivew recent findings showing that glial cells are active regulators in brain functions through phagocytosis and that changes in glial phagocytosis contribute to the pathogenesis of various neurodegenerative diseases. A better understanding of the cellular and molecular mechanisms of glial phagocytosis in healthy and diseased brains will greatly improve our current approach in treating these diseases.

Astrocytes , Brain , Complement Pathway, Classical , Microglia , Neurodegenerative Diseases , Neuroglia , Phagocytosis , Protein Aggregates , Synapses