Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros












Base de dados
Intervalo de ano de publicação
1.
Curr Opin Neurobiol ; 77: 102630, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36209695

RESUMO

Frontal cortex is thought to underlie many advanced cognitive capacities, from self-control to long term planning. Reflecting these diverse demands, frontal neural activity is notoriously idiosyncratic, with tuning properties that are correlated with endless numbers of behavioral and task features. This menagerie of tuning has made it difficult to extract organizing principles that govern frontal neural activity. Here, we contrast two successful yet seemingly incompatible approaches that have begun to address this challenge. Inspired by the indecipherability of single-neuron tuning, the first approach casts frontal computations as dynamical trajectories traversed by arbitrary mixtures of neurons. The second approach, by contrast, attempts to explain the functional diversity of frontal activity with the biological diversity of cortical cell-types. Motivated by the recent discovery of functional clusters in frontal neurons, we propose a consilience between these population and cell-type-specific approaches to neural computations, advancing the conjecture that evolutionarily inherited cell-type constraints create the scaffold within which frontal population dynamics must operate.


Assuntos
Cognição , Lobo Frontal , Lobo Frontal/fisiologia , Cognição/fisiologia , Neurônios/fisiologia
2.
Nat Commun ; 13(1): 1676, 2022 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35354804

RESUMO

Running profoundly alters stimulus-response properties in mouse primary visual cortex (V1), but its effect in higher-order visual cortex is under-explored. Here we systematically investigate how visual responses vary with locomotive state across six visual areas and three cortical layers using a massive dataset from the Allen Brain Institute. Although previous work has shown running speed to be positively correlated with neural activity in V1, here we show that the sign of correlations between speed and neural activity varies across extra-striate cortex, and is even negative in anterior extra-striate cortex. Nevertheless, across all visual cortices, neural responses can be decoded more accurately during running than during stationary periods. We show that this effect is not attributable to changes in population activity structure, and propose that it instead arises from an increase in reliability of single-neuron responses during locomotion.


Assuntos
Roedores , Córtex Visual , Animais , Locomoção/fisiologia , Camundongos , Estimulação Luminosa , Reprodutibilidade dos Testes , Córtex Visual/fisiologia
3.
Nat Neurosci ; 22(11): 1761-1770, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31659335

RESUMO

Systems neuroscience seeks explanations for how the brain implements a wide variety of perceptual, cognitive and motor tasks. Conversely, artificial intelligence attempts to design computational systems based on the tasks they will have to solve. In artificial neural networks, the three components specified by design are the objective functions, the learning rules and the architectures. With the growing success of deep learning, which utilizes brain-inspired architectures, these three designed components have increasingly become central to how we model, engineer and optimize complex artificial learning systems. Here we argue that a greater focus on these components would also benefit systems neuroscience. We give examples of how this optimization-based framework can drive theoretical and experimental progress in neuroscience. We contend that this principled perspective on systems neuroscience will help to generate more rapid progress.


Assuntos
Inteligência Artificial , Aprendizado Profundo , Redes Neurais de Computação , Animais , Encéfalo/fisiologia , Humanos
4.
Neuron ; 93(4): 822-839.e6, 2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28162807

RESUMO

Pain thresholds are, in part, set as a function of emotional and internal states by descending modulation of nociceptive transmission in the spinal cord. Neurons of the rostral ventromedial medulla (RVM) are thought to critically contribute to this process; however, the neural circuits and synaptic mechanisms by which distinct populations of RVM neurons facilitate or diminish pain remain elusive. Here we used in vivo opto/chemogenetic manipulations and trans-synaptic tracing of genetically identified dorsal horn and RVM neurons to uncover an RVM-spinal cord-primary afferent circuit controlling pain thresholds. Unexpectedly, we found that RVM GABAergic neurons facilitate mechanical pain by inhibiting dorsal horn enkephalinergic/GABAergic interneurons. We further demonstrate that these interneurons gate sensory inputs and control pain through temporally coordinated enkephalin- and GABA-mediated presynaptic inhibition of somatosensory neurons. Our results uncover a descending disynaptic inhibitory circuit that facilitates mechanical pain, is engaged during stress, and could be targeted to establish higher pain thresholds. VIDEO ABSTRACT.


Assuntos
Encefalinas/metabolismo , Neurônios GABAérgicos/metabolismo , Interneurônios/metabolismo , Vias Neurais/fisiologia , Dor/fisiopatologia , Medula Espinal/metabolismo , Animais , Tronco Encefálico/metabolismo , Tronco Encefálico/fisiopatologia , Bulbo/metabolismo , Camundongos Transgênicos , Corno Dorsal da Medula Espinal/metabolismo , Corno Dorsal da Medula Espinal/fisiopatologia
5.
Cell Rep ; 17(6): 1699-1710, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27806306

RESUMO

Spinal dorsal horn circuits receive, process, and transmit somatosensory information. To understand how specific components of these circuits contribute to behavior, it is critical to be able to directly modulate their activity in unanesthetized in vivo conditions. Here, we develop experimental tools that enable optogenetic control of spinal circuitry in freely moving mice using commonly available materials. We use these tools to examine mechanosensory processing in the spinal cord and observe that optogenetic activation of somatostatin-positive interneurons facilitates both mechanosensory and itch-related behavior, while reversible chemogenetic inhibition of these neurons suppresses mechanosensation. These results extend recent findings regarding the processing of mechanosensory information in the spinal cord and indicate the potential for activity-induced release of the somatostatin neuropeptide to affect processing of itch. The spinal implant approach we describe here is likely to enable a wide range of studies to elucidate spinal circuits underlying pain, touch, itch, and movement.


Assuntos
Mecanotransdução Celular , Medula Espinal/fisiologia , Animais , Feminino , Histamina , Interneurônios/fisiologia , Luz , Camundongos Endogâmicos C57BL , Fibras Ópticas , Optogenética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Prurido/patologia , Prurido/fisiopatologia , Somatostatina/metabolismo
6.
Sci Transl Med ; 8(337): 337rv5, 2016 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-27147590

RESUMO

Optogenetics offers promise for dissecting the complex neural circuits of the spinal cord and peripheral nervous system and has therapeutic potential for addressing unmet clinical needs. Much progress has been made to enable optogenetic control in normal and disease states, both in proof-of-concept and mechanistic studies in rodent models. In this Review, we discuss challenges in using optogenetics to study the mammalian spinal cord and peripheral nervous system, synthesize common features that unite the work done thus far, and describe a route forward for the successful application of optogenetics to translational research beyond the brain.


Assuntos
Encéfalo/metabolismo , Optogenética/métodos , Sistema Nervoso Periférico/metabolismo , Medula Espinal/metabolismo , Animais , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...