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1.
Yakugaku Zasshi ; 140(10): 1207-1212, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32999199

RESUMO

T-type calcium channels are low-threshold voltage-gated calcium channel and characterized by unique electrophysiological properties such as fast inactivation and slow deactivation kinetics. All subtypes of T-type calcium channel (Cav3.1, 3.2 and 3.3) are widely expressed in the central nerve system, and they have an important role in homeostasis of sleep, pain response, and development of epilepsy. Recently, several reports suggest that T-type calcium channels may mediate neuronal plasticity in the mouse brain. We succeeded to develop T-type calcium channel enhancer ethyl 8'-methyl-2',4-dioxo-2-(piperidin-1-yl)-2'H-spiro[cyclopentane-1,3'-imidazo[1,2-a]pyridine]-2-ene-3-carboxylate (SAK3) which enhances Cav3.1 and 3.3 currents in each-channel expressed neuro2A cells. SAK3 can promote acetylcholine (ACh) release in the mouse hippocampus via enhancing T-type calcium channel. In this review, we have introduced the role of T-type calcium channel, especially Cav3.1 channel in the mouse hippocampus based on our previous data using SAK3 and Cav3.1 knockout mice.


Assuntos
Canais de Cálcio Tipo T/efeitos dos fármacos , Canais de Cálcio Tipo T/fisiologia , Imidazóis/farmacologia , Neurônios/fisiologia , Compostos de Espiro/farmacologia , Acetilcolina/metabolismo , Animais , Encéfalo/fisiologia , Canais de Cálcio Tipo T/genética , Canais de Cálcio Tipo T/metabolismo , Células Cultivadas , Sistema Nervoso Central/metabolismo , Fenômenos Eletrofisiológicos , Epilepsia/etiologia , Expressão Gênica/efeitos dos fármacos , Hipocampo/metabolismo , Homeostase , Camundongos , Plasticidade Neuronal , Dor/etiologia , Ratos , Sono/fisiologia
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1512-1515, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018278

RESUMO

The patient-clinician relationship is known to significantly affect the pain experience, as empathy, mutual trust and therapeutic alliance can significantly modulate pain perception and influence clinical therapy outcomes. The aim of the present study was to use an EEG hyperscanning setup to identify brain and behavioral mechanisms supporting the patient-clinician relationship while this clinical dyad is engaged in a therapeutic interaction. Our previous study applied fMRI hyperscanning to investigate whether brain concordance is linked with analgesia experienced by a patient while undergoing treatment by the clinician. In this current hyperscanning project we investigated similar outcomes for the patient-clinician dyad exploiting the high temporal resolution of EEG and the possibility to acquire the signals while patients and clinicians were present in the same room and engaged in a face-to-face interaction under an experimentally-controlled therapeutic context. Advanced source localization methods allowed for integration of spatial and spectral information in order to assess brain correlates of therapeutic alliance and pain perception in different clinical interaction contexts. Preliminary results showed that both behavioral and brain responses across the patient-clinician dyad were significantly affected by the interaction style.Clinical Relevance- The context of a clinical intervention can significantly impact the treatment of chronic pain. Effective therapeutic alliance, based on empathy, mutual trust, and warmth can improve treatment adherence and clinical outcomes. A deeper scientific understanding of the brain and behavioral mechanisms underlying an optimal patient-clinician interaction may lead to improved quality of clinical care and physician training, as well as better understanding of the social aspects of the biopsychosocial model mediating analgesia in chronic pain patients.


Assuntos
Encéfalo , Dor Crônica , Manejo da Dor , Relações Profissional-Paciente , Encéfalo/fisiologia , Humanos , Imagem por Ressonância Magnética , Percepção da Dor
3.
Nat Commun ; 11(1): 5004, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020473

RESUMO

Adaptive brain function requires that sensory impressions of the social and natural milieu are dynamically incorporated into intrinsic brain activity. While dynamic switches between brain states have been well characterised in resting state acquisitions, the remodelling of these state transitions by engagement in naturalistic stimuli remains poorly understood. Here, we show that the temporal dynamics of brain states, as measured in fMRI, are reshaped from predominantly bistable transitions between two relatively indistinct states at rest, toward a sequence of well-defined functional states during movie viewing whose transitions are temporally aligned to specific features of the movie. The expression of these brain states covaries with different physiological states and reflects subjectively rated engagement in the movie. In sum, a data-driven decoding of brain states reveals the distinct reshaping of functional network expression and reliable state transitions that accompany the switch from resting state to perceptual immersion in an ecologically valid sensory experience.


Assuntos
Encéfalo/fisiologia , Filmes Cinematográficos , Adulto , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Feminino , Frequência Cardíaca/fisiologia , Humanos , Imagem por Ressonância Magnética , Masculino , Filmes Cinematográficos/classificação , Filmes Cinematográficos/estatística & dados numéricos , Percepção/fisiologia , Pupila/fisiologia , Descanso/fisiologia , Inquéritos e Questionários , Adulto Jovem
4.
PLoS Comput Biol ; 16(9): e1008165, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32941457

RESUMO

Combining information from multiple sources is a fundamental operation performed by networks of neurons in the brain, whose general principles are still largely unknown. Experimental evidence suggests that combination of inputs in cortex relies on nonlinear summation. Such nonlinearities are thought to be fundamental to perform complex computations. However, these non-linearities are inconsistent with the balanced-state model, one of the most popular models of cortical dynamics, which predicts networks have a linear response. This linearity is obtained in the limit of very large recurrent coupling strength. We investigate the stationary response of networks of spiking neurons as a function of coupling strength. We show that, while a linear transfer function emerges at strong coupling, nonlinearities are prominent at finite coupling, both at response onset and close to saturation. We derive a general framework to classify nonlinear responses in these networks and discuss which of them can be captured by rate models. This framework could help to understand the diversity of non-linearities observed in cortical networks.


Assuntos
Potenciais de Ação/fisiologia , Modelos Neurológicos , Rede Nervosa/citologia , Rede Nervosa/fisiologia , Neurônios/fisiologia , Animais , Encéfalo/citologia , Encéfalo/fisiologia , Biologia Computacional , Haplorrinos , Camundongos , Dinâmica não Linear
5.
PLoS Comput Biol ; 16(9): e1008146, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32970679

RESUMO

According to the efficient coding hypothesis, sensory systems are adapted to maximize their ability to encode information about the environment. Sensory neurons play a key role in encoding by selectively modulating their firing rate for a subset of all possible stimuli. This pattern of modulation is often summarized via a tuning curve. The optimally efficient distribution of tuning curves has been calculated in variety of ways for one-dimensional (1-D) stimuli. However, many sensory neurons encode multiple stimulus dimensions simultaneously. It remains unclear how applicable existing models of 1-D tuning curves are for neurons tuned across multiple dimensions. We describe a mathematical generalization that builds on prior work in 1-D to predict optimally efficient multidimensional tuning curves. Our results have implications for interpreting observed properties of neuronal populations. For example, our results suggest that not all tuning curve attributes (such as gain and bandwidth) are equally useful for evaluating the encoding efficiency of a population.


Assuntos
Biologia Computacional/métodos , Modelos Neurológicos , Células Receptoras Sensoriais/fisiologia , Encéfalo/fisiologia , Humanos
7.
Nat Commun ; 11(1): 4715, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948772

RESUMO

Animal-fMRI is a powerful method to understand neural mechanisms of cognition, but it remains a major challenge to scan actively participating small animals under low-stress conditions. Here, we present an event-related functional MRI platform in awake pigeons using single-shot RARE fMRI to investigate the neural fundaments for visually-guided decision making. We established a head-fixated Go/NoGo paradigm, which the animals quickly learned under low-stress conditions. The animals were motivated by water reward and behavior was assessed by logging mandibulations during the fMRI experiment with close to zero motion artifacts over hundreds of repeats. To achieve optimal results, we characterized the species-specific hemodynamic response function. As a proof-of-principle, we run a color discrimination task and discovered differential neural networks for Go-, NoGo-, and response execution-phases. Our findings open the door to visualize the neural fundaments of perceptual and cognitive functions in birds-a vertebrate class of which some clades are cognitively on par with primates.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Cognição/fisiologia , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/veterinária , Vigília , Animais , Artefatos , Comportamento Animal/fisiologia , Mapeamento Encefálico , Columbidae , Humanos , Inibição Psicológica , Aprendizagem , Movimento (Física) , Redes Neurais de Computação , Recompensa
8.
Nat Commun ; 11(1): 4429, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868772

RESUMO

Can humans be trained to make strategic use of latent representations in their own brains? We investigate how human subjects can derive reward-maximizing choices from intrinsic high-dimensional information represented stochastically in neural activity. Reward contingencies are defined in real-time by fMRI multivoxel patterns; optimal action policies thereby depend on multidimensional brain activity taking place below the threshold of consciousness, by design. We find that subjects can solve the task within two hundred trials and errors, as their reinforcement learning processes interact with metacognitive functions (quantified as the meaningfulness of their decision confidence). Computational modelling and multivariate analyses identify a frontostriatal neural mechanism by which the brain may untangle the 'curse of dimensionality': synchronization of confidence representations in prefrontal cortex with reward prediction errors in basal ganglia support exploration of latent task representations. These results may provide an alternative starting point for future investigations into unconscious learning and functions of metacognition.


Assuntos
Encéfalo/fisiologia , Reforço Psicológico , Adulto , Estado de Consciência , Tomada de Decisões , Feminino , Humanos , Aprendizagem , Imagem por Ressonância Magnética/métodos , Masculino , Metacognição/fisiologia , Adulto Jovem
10.
PLoS One ; 15(9): e0236155, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32915780

RESUMO

Large brains in prey may select for adoption of anti-predator behavior that facilitates escape. Prey species with relatively large brains have been shown to be less likely to fall prey to predators. This results in the prediction that individuals that have been captured by predators on average should have smaller brains than sympatric conspecifics. We exploited the fact that Eurasian pygmy owls Glaucidium passerinum hoard small mammals and birds in cavities and nest-boxes for over-winter survival, allowing for comparison of the phenotype of prey with that of live conspecifics. In Northern Europe, main prey of pygmy owls are voles of the genera Myodes and Microtus, while forest birds and shrews are the most important alternative prey. Large fluctuations (amplitude 100-200-fold) in vole populations induce rapid numerical responses of pygmy owls to main prey populations, which in turn results in varying predation pressure on small birds. We found, weighed and measured 153 birds in food-stores of pygmy owls and mist-netted, weighed and measured 333 live birds of 12 species in central-western Finland during two autumns with low (2017) and high (2018) pygmy owl predation risk. In two autumns, individuals with large brains were captured later compared to individuals with small brains, consistent with the hypothesis that such individuals survived for longer. Avian prey of pygmy owls had smaller heads than live birds in autumn 2018 when predation risk by pygmy owls was high. This difference in head size was not significant in 2017 when predation risk by pygmy owls was reduced. Finally, avian survivors were in better body condition than avian prey individuals. These findings are consistent with the hypothesis that pygmy owls differentially prey on birds in poor condition with small brains. These findings are consistent with the hypothesis that predation risk imposed by pygmy owls on small birds in boreal forests varies depending on the abundance of the main prey (voles).


Assuntos
Comportamento Predatório , Estrigiformes , Animais , Arvicolinae/fisiologia , Encéfalo/fisiologia , Feminino , Masculino , Tamanho do Órgão , Estações do Ano , Musaranhos/fisiologia , Estrigiformes/fisiologia , Taiga
11.
Nat Commun ; 11(1): 4632, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32934230

RESUMO

Mapping neuroanatomy is a foundational goal towards understanding brain function. Electron microscopy (EM) has been the gold standard for connectivity analysis because nanoscale resolution is necessary to unambiguously resolve synapses. However, molecular information that specifies cell types is often lost in EM reconstructions. To address this, we devise a light microscopy approach for connectivity analysis of defined cell types called spectral connectomics. We combine multicolor labeling (Brainbow) of neurons with multi-round immunostaining Expansion Microscopy (miriEx) to simultaneously interrogate morphology, molecular markers, and connectivity in the same brain section. We apply this strategy to directly link inhibitory neuron cell types with their morphologies. Furthermore, we show that correlative Brainbow and endogenous synaptic machinery immunostaining can define putative synaptic connections between neurons, as well as map putative inhibitory and excitatory inputs. We envision that spectral connectomics can be applied routinely in neurobiology labs to gain insights into normal and pathophysiological neuroanatomy.


Assuntos
Conectoma/métodos , Microscopia/métodos , Neurônios/fisiologia , Animais , Encéfalo/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Neuroanatomia , Neurônios/química , Sinapses/química , Sinapses/fisiologia
12.
PLoS One ; 15(9): e0234749, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32966291

RESUMO

Traumatic brain injury (TBI) can lead to neurodegeneration in the injured circuitry, either through primary structural damage to the neuron or secondary effects that disrupt key cellular processes. Moreover, traumatic injuries can preferentially impact subpopulations of neurons, but the functional network effects of these targeted degeneration profiles remain unclear. Although isolating the consequences of complex injury dynamics and long-term recovery of the circuit can be difficult to control experimentally, computational networks can be a powerful tool to analyze the consequences of injury. Here, we use the Izhikevich spiking neuron model to create networks representative of cortical tissue. After an initial settling period with spike-timing-dependent plasticity (STDP), networks developed rhythmic oscillations similar to those seen in vivo. As neurons were sequentially removed from the network, population activity rate and oscillation dynamics were significantly reduced. In a successive period of network restructuring with STDP, network activity levels returned to baseline for some injury levels and oscillation dynamics significantly improved. We next explored the role that specific neurons have in the creation and termination of oscillation dynamics. We determined that oscillations initiate from activation of low firing rate neurons with limited structural inputs. To terminate oscillations, high activity excitatory neurons with strong input connectivity activate downstream inhibitory circuitry. Finally, we confirm the excitatory neuron population role through targeted neurodegeneration. These results suggest targeted neurodegeneration can play a key role in the oscillation dynamics after injury.


Assuntos
Lesões Encefálicas Traumáticas/fisiopatologia , Simulação por Computador , Modelos Neurológicos , Rede Nervosa/fisiopatologia , Doenças Neurodegenerativas/fisiopatologia , Potenciais de Ação , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Lesões Encefálicas Traumáticas/complicações , Humanos , Rede Nervosa/fisiologia , Doenças Neurodegenerativas/etiologia , Plasticidade Neuronal , Neurônios/patologia , Neurônios/fisiologia
13.
Nature ; 586(7827): 31-32, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32939081
14.
PLoS One ; 15(8): e0238373, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866215

RESUMO

The term "retroactive avoidance" refers to a special class of effects of future stimulus presentations on past behavioral responses. Specifically, it refers to the anticipatory avoidance of aversive stimuli that were unpredictable through random selection after the response. This phenomenon is supposed to challenge the common view of the arrow of time and the direction of causality. Preliminary evidence of "retroactive avoidance" has been published in mainstream psychological journals and started a heated debate about the robustness and the true existence of this effect. A series of seven experiments published in 2014 in the Journal of Consciousness Studies (Maier et al., 2014) tested the influence of randomly drawn future negative picture presentations on avoidance responses based on key presses preceding them. The final study in that series used a sophisticated quantum-based random stimulus selection procedure and implemented the most severe test of retroactive avoidance within this series. Evidence for the effect, though significant, was meager and anecdotal, Bayes factor (BF10) = 2. The research presented here represents an attempt to exactly replicate the original effect with a high-power (N = 2004) preregistered multi-lab study. The results indicate that the data favored the null effect (i.e., absence of retroactive avoidance) with a BF01 = 4.38. Given the empirical strengths of the study, namely its preregistration, multi-lab approach, high power, and Bayesian analysis used, this failed replication questions the validity and robustness of the original findings. Not reaching a decisive level of Bayesian evidence and not including skeptical researchers may be considered limitations of this study. Exploratory analyses of the change in evidence for the effect across time, performed on a post-hoc basis, revealed several potentially interesting anomalies in the data that might guide future research in this area.


Assuntos
Aprendizagem da Esquiva/fisiologia , Encéfalo/fisiologia , Estudantes/psicologia , Adulto , Teorema de Bayes , Feminino , Humanos , Masculino , Adulto Jovem
15.
CBE Life Sci Educ ; 19(3): es8, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32870083

RESUMO

Cognitive neuroscience research is typically conducted in controlled laboratory environments that hold very little resemblance to science, technology, engineering, and mathematics classrooms. Fortunately, recent advances in portable electroencephalography technology now allow researchers to collect brain data from groups of students in real-world classrooms. Even though this line of research is still new, there is growing evidence that students' engagement, memory retention, and social dynamics are reflected in the brain-to-brain synchrony between students and teachers (i.e., the similarity in their brain responses). In this Essay, I will provide an overview of this emerging line of research, discuss how this approach can facilitate new collaborations between neuroscientists and discipline-based education researchers, and propose directions for future research.


Assuntos
Encéfalo/fisiologia , Engenharia/educação , Matemática/educação , Ciência/educação , Tecnologia/educação , Universidades , Humanos , Relações Interpessoais , Estudantes/psicologia
16.
PLoS One ; 15(9): e0238318, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881901

RESUMO

Knowledge on neural processing during complex non-stationary motion sequences of sport-specific movements still remains elusive. Hence, we aimed at investigating hemodynamic response alterations during a basketball slalom dribbling task (BSDT) using multi-distance functional near-infrared spectroscopy (fNIRS) in 23 participants (12 females). Additionally, we quantified how the brain adapts its processing as a function of altered hand use (dominant right hand (DH) vs. non-dominant left hand (NDH) vs. alternating hands (AH)) and pace of execution (slow vs. fast) in BSDT. We found that BSDT activated bilateral premotor cortex (PMC), supplementary motor cortex (SMA), primary motor cortex (M1) as well as inferior parietal cortex and somatosensory association cortex. Slow dominant hand dribbling (DHslow) evoked lower contralateral hemodynamic responses in sensorimotor regions compared to fast dribbling (DHfast). Furthermore, during DHslow dribbling, we found lower hemodynamic responses in ipsilateral M1 as compared to dribbling with alternating hands (AHslow). Hence, altered task complexity during BSDT induced differential hemodynamic response patterns. Furthermore, a correlation analysis revealed that lower levels of perceived task complexity are associated with lower hemodynamic responses in ipsilateral PMC-SMA, which is an indicator for neuronal efficiency in participants with better basketball dribbling skills. The present study extends previous findings by showing that varying levels of task complexity are reflected by specific hemodynamic response alterations even during sports-relevant motor behavior. Taken together, we suggest that quantifying brain activation during complex movements is a prerequisite for assessing brain-behavior relations and optimizing motor performance.


Assuntos
Encéfalo/fisiologia , Hemodinâmica , Adulto , Basquetebol , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Feminino , Lateralidade Funcional/fisiologia , Hemoglobinas/química , Humanos , Masculino , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Adulto Jovem
17.
J Transl Med ; 18(1): 322, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32847594

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic has led to a declaration of a Public Health Emergency of International Concern by the World Health Organization. As of May 18, 2020, there have been more than 4.7 million cases and over 316,000 deaths worldwide. COVID-19 is caused by a highly infectious novel coronavirus known as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), leading to an acute infectious disease with mild-to-severe clinical symptoms such as flu-like symptoms, fever, headache, dry cough, muscle pain, loss of smell and taste, increased shortness of breath, bilateral viral pneumonia, conjunctivitis, acute respiratory distress syndromes, respiratory failure, cytokine release syndrome (CRS), sepsis, etc. While physicians and scientists have yet to discover a treatment, it is imperative that we urgently address 2 questions: how to prevent infection in immunologically naive individuals and how to treat severe symptoms such as CRS, acute respiratory failure, and the loss of somatosensation. Previous studies from the 1918 influenza pandemic have suggested vitamin D's non-classical role in reducing lethal pneumonia and case fatality rates. Recent clinical trials also reported that vitamin D supplementation can reduce incidence of acute respiratory infection and the severity of respiratory tract diseases in adults and children. According to our literature search, there are no similar findings of clinical trials that have been published as of July 1st, 2020, in relation to the supplementation of vitamin D in the potential prevention and treatment for COVID-19. In this review, we summarize the potential role of vitamin D extra-renal metabolism in the prevention and treatment of the SARS-CoV-2 infection, helping to bring us slightly closer to fulfilling that goal. We will focus on 3 major topics here: 1. Vitamin D might aid in preventing SARS-CoV-2 infection: Vitamin D: Overview of Renal and Extra-renal metabolism and regulation. Vitamin D: Overview of molecular mechanism and multifaceted functions beyond skeletal homeostasis. Vitamin D: Overview of local immunomodulation in human infectious diseases. Anti-viral infection. Anti-malaria and anti-systemic lupus erythematosus (SLE). 2. Vitamin D might act as a strong immunosuppressant inhibiting cytokine release syndrome in COVID-19: Vitamin D: Suppression of key pro-inflammatory pathways including nuclear factor kappa B (NF-kB), interleukin-6 (IL-6), and tumor necrosis factor (TNF). 3. Vitamin D might prevent loss of neural sensation in COVID-19 by stimulating expression of neurotrophins like Nerve Growth Factor (NGF): Vitamin D: Induction of key neurotrophic factors. .


Assuntos
Quimioprevenção/métodos , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/terapia , Imunomodulação/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/terapia , Vitamina D/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/fisiologia , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/fisiopatologia , Suplementos Nutricionais , Humanos , Sistema Imunitário/efeitos dos fármacos , Sistema Imunitário/fisiologia , Neuroproteção/efeitos dos fármacos , Pneumonia Viral/epidemiologia , Pneumonia Viral/fisiopatologia , Vitamina D/metabolismo , Vitamina D/farmacologia , Deficiência de Vitamina D/dietoterapia , Deficiência de Vitamina D/epidemiologia , Deficiência de Vitamina D/metabolismo , Deficiência de Vitamina D/virologia
18.
Nat Commun ; 11(1): 4275, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32848155

RESUMO

New neurons are generated in adult mammals. Adult hippocampal neurogenesis is considered to play an important role in cognition and mental health. The number and properties of newly born neurons are regulatable by a broad range of physiological and pathological conditions. To begin to understand the underlying cellular mechanisms and functional relevance of adult neurogenesis, many studies rely on quantification of adult-born neurons. However, lack of standardized methods to quantify new neurons is impeding research reproducibility across laboratories. Here, we review the importance of stereology, and propose why and how it should be applied to the study of adult neurogenesis.


Assuntos
Encéfalo/citologia , Encéfalo/fisiologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/fisiologia , Neurogênese/fisiologia , Adulto , Células-Tronco Adultas/citologia , Células-Tronco Adultas/fisiologia , Animais , Giro Denteado/citologia , Giro Denteado/fisiologia , Humanos , Modelos Neurológicos , Plasticidade Neuronal
19.
Nat Commun ; 11(1): 4234, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843643

RESUMO

Brain-machine interfaces are promising tools to restore lost motor functions and probe brain functional mechanisms. As the number of recording electrodes has been exponentially rising, the signal processing capability of brain-machine interfaces is falling behind. One of the key bottlenecks is that they adopt conventional von Neumann architecture with digital computation that is fundamentally different from the working principle of human brain. In this work, we present a memristor-based neural signal analysis system, where the bio-plausible characteristics of memristors are utilized to analyze signals in the analog domain with high efficiency. As a proof-of-concept demonstration, memristor arrays are used to implement the filtering and identification of epilepsy-related neural signals, achieving a high accuracy of 93.46%. Remarkably, our memristor-based system shows nearly 400× improvements in the power efficiency compared to state-of-the-art complementary metal-oxide-semiconductor systems. This work demonstrates the feasibility of using memristors for high-performance neural signal analysis in next-generation brain-machine interfaces.


Assuntos
Interfaces Cérebro-Computador , Redes Neurais de Computação , Processamento de Sinais Assistido por Computador/instrumentação , Encéfalo/fisiologia , Computadores Analógicos , Sinapses Elétricas/fisiologia , Epilepsia/fisiopatologia , Humanos , Modelos Neurológicos , Transistores Eletrônicos
20.
PLoS One ; 15(8): e0236897, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760113

RESUMO

Advancing age affects the recruitment of task related neural resources thereby changing the efficiency, capacity and use of compensatory processes. With advancing age, brain activity may therefore increase within a region or be reorganized to utilize different brain regions. The different brain regions may be exclusive to old adults or accessible to young and old alike, but non-optimal. Interference during verbal working memory information retention recruits parahippocampal brain regions in young adults similar to brain activity recruited by old adults in the absence of external interference. The current work tests the hypothesis that old adults recruit neural resources to combat increases in age-related intrinsic noise that young adults recruit during high levels of interference during information retention. This experiment administered a verbal delayed item recognition task with low and high levels of an interfering addition task during information maintenance. Despite strong age-related behavioral effects, brain imaging results demonstrated no significant interaction effects between age group and the interference or memory tasks. Significant effects were only found for the interaction between interference level and memory load within the inferior frontal cortex, supplementary motor cortex and posterior supramarginal regions. Results demonstrate that neural resources were shared when facing increasing memory load and interference. The combined cognitive demands resulted in brain activity reaching a neural capacity limit which was similar for both age groups and which brain activation did not increase above. Despite significant behavioral differences the neural capacity limited the detection of age group differences in brain activity.


Assuntos
Encéfalo/fisiologia , Memória , Adulto , Envelhecimento/fisiologia , Feminino , Humanos , Masculino , Córtex Pré-Frontal/fisiologia , Tempo de Reação , Lobo Temporal/fisiologia
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