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1.
Physiol Rev ; 101(1): 353-415, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32816652

RESUMO

The array of whiskers on the snout provides rodents with tactile sensory information relating to the size, shape and texture of objects in their immediate environment. Rodents can use their whiskers to detect stimuli, distinguish textures, locate objects and navigate. Important aspects of whisker sensation are thought to result from neuronal computations in the whisker somatosensory cortex (wS1). Each whisker is individually represented in the somatotopic map of wS1 by an anatomical unit named a 'barrel' (hence also called barrel cortex). This allows precise investigation of sensory processing in the context of a well-defined map. Here, we first review the signaling pathways from the whiskers to wS1, and then discuss current understanding of the various types of excitatory and inhibitory neurons present within wS1. Different classes of cells can be defined according to anatomical, electrophysiological and molecular features. The synaptic connectivity of neurons within local wS1 microcircuits, as well as their long-range interactions and the impact of neuromodulators, are beginning to be understood. Recent technological progress has allowed cell-type-specific connectivity to be related to cell-type-specific activity during whisker-related behaviors. An important goal for future research is to obtain a causal and mechanistic understanding of how selected aspects of tactile sensory information are processed by specific types of neurons in the synaptically connected neuronal networks of wS1 and signaled to downstream brain areas, thus contributing to sensory-guided decision-making.


Assuntos
Vias Neurais/fisiologia , Sensação/fisiologia , Córtex Somatossensorial/fisiologia , Vibrissas/fisiologia , Animais , Encefalopatias/fisiopatologia , Interfaces Cérebro-Computador , Humanos , Camundongos , Transdução de Sinais/fisiologia , Vibrissas/inervação
2.
PLoS Biol ; 20(5): e3001667, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35639787

RESUMO

Excitatory and inhibitory neurons in diverse cortical regions are likely to contribute differentially to the transformation of sensory information into goal-directed motor plans. Here, we investigate the relative changes across mouse sensorimotor cortex in the activity of putative excitatory and inhibitory neurons-categorized as regular spiking (RS) or fast spiking (FS) according to their action potential (AP) waveform-comparing before and after learning of a whisker detection task with delayed licking as perceptual report. Surprisingly, we found that the whisker-evoked activity of RS versus FS neurons changed in opposite directions after learning in primary and secondary whisker motor cortices, while it changed similarly in primary and secondary orofacial motor cortices. Our results suggest that changes in the balance of excitation and inhibition in local circuits concurrent with changes in the long-range synaptic inputs in distinct cortical regions might contribute to performance of delayed sensory-to-motor transformation.


Assuntos
Córtex Motor , Córtex Somatossensorial , Potenciais de Ação/fisiologia , Animais , Camundongos , Córtex Motor/fisiologia , Neurônios/fisiologia , Córtex Somatossensorial/fisiologia , Vibrissas
3.
Nat Rev Neurosci ; 20(9): 533-546, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31367018

RESUMO

Tactile sensory information from facial whiskers provides nocturnal tunnel-dwelling rodents, including mice and rats, with important spatial and textural information about their immediate surroundings. Whiskers are moved back and forth to scan the environment (whisking), and touch signals from each whisker evoke sparse patterns of neuronal activity in whisker-related primary somatosensory cortex (wS1; barrel cortex). Whisking is accompanied by desynchronized brain states and cell-type-specific changes in spontaneous and evoked neuronal activity. Tactile information, including object texture and location, appears to be computed in wS1 through integration of motor and sensory signals. wS1 also directly controls whisker movements and contributes to learned, whisker-dependent, goal-directed behaviours. The cell-type-specific neuronal circuitry in wS1 that contributes to whisker sensory perception is beginning to be defined.


Assuntos
Rede Nervosa/fisiologia , Transdução de Sinais/fisiologia , Córtex Somatossensorial/fisiologia , Tato/fisiologia , Vibrissas/fisiologia , Animais , Camundongos , Ratos , Roedores , Córtex Sensório-Motor/fisiologia , Vibrissas/inervação
4.
Neuropsychol Rehabil ; 33(8): 1430-1455, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35929897

RESUMO

This systematic review aimed to present the comparison of the impacts of conventional exercise and virtual reality (VR) exergaming on the physical and cognitive abilities of people with multiple sclerosis (PwMS). The literature search was conducted in the EMBASE, PubMed, Scopus, CINAHL, and Cochrane Library databases. Eligible studies were identified by independent reviewers based on the title, abstract and full-texts. Studies were limited to randomized clinical trials published in peer-reviewed journals in English that compared conventional exercise with VR-exergaming for improving the physical and cognitive abilities of PwMS. Selected studies were assessed for their risk of bias and the major findings of the reviewed studies were analyzed descriptively. The search identified 239 articles of which 10 studies met the eligibility criteria. Despite these studies employing strategies to control biases, some risks of bias remain. Various gaming platforms and conventional exercises were used based on the extent of technologies and therapy regimens. The selected studies used measures of physical and cognitive abilities to compare VR-exergaming with conventional exercise. This review suggests positive impacts of both VR-exergaming and conventional exercise in MS rehabilitation. We also found that VR-exergaming generally exceeded conventional exercise for improving physical and cognitive abilities, psychosocial status, and fatigue.


Assuntos
Esclerose Múltipla , Realidade Virtual , Humanos , Jogos Eletrônicos de Movimento , Terapia por Exercício , Emprego , Esclerose Múltipla/reabilitação
5.
Annu Rev Neurosci ; 37: 183-203, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24821429

RESUMO

Facial muscles drive whisker movements, which are important for active tactile sensory perception in mice and rats. These whisker muscles are innervated by cholinergic motor neurons located in the lateral facial nucleus. The whisker motor neurons receive synaptic inputs from premotor neurons, which are located within the brain stem, the midbrain, and the neocortex. Complex, distributed neural circuits therefore regulate whisker movement during behavior. This review focuses specifically on cortical whisker motor control. The whisker primary motor cortex (M1) strongly innervates brain stem reticular nuclei containing whisker premotor neurons, which might form a central pattern generator for rhythmic whisker protraction. In a parallel analogous pathway, the whisker primary somatosensory cortex (S1) strongly projects to the brain stem spinal trigeminal interpolaris nucleus, which contains whisker premotor neurons innervating muscles for whisker retraction. These anatomical pathways may play important functional roles, since stimulation of M1 drives exploratory rhythmic whisking, whereas stimulation of S1 drives whisker retraction.


Assuntos
Tronco Encefálico/fisiologia , Córtex Motor/fisiologia , Córtex Somatossensorial/fisiologia , Vibrissas/inervação , Vibrissas/fisiologia , Animais , Núcleo do Nervo Facial/fisiologia , Neurônios Motores/fisiologia , Inibição Neural/fisiologia , Vias Neurais
6.
Cereb Cortex ; 31(5): 2610-2624, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33350443

RESUMO

Synapses are the fundamental elements of the brain's complicated neural networks. Although the ultrastructure of synapses has been extensively studied, the difference in how synaptic inputs are organized onto distinct neuronal types is not yet fully understood. Here, we examined the cell-type-specific ultrastructure of proximal processes from the soma of parvalbumin-positive (PV+) and somatostatin-positive (SST+) GABAergic neurons in comparison with a pyramidal neuron in the mouse primary visual cortex (V1), using serial block-face scanning electron microscopy. Interestingly, each type of neuron organizes excitatory and inhibitory synapses in a unique way. First, we found that a subset of SST+ neurons are spiny, having spines on both soma and dendrites. Each of those spines has a highly complicated structure that has up to eight synaptic inputs. Next, the PV+ and SST+ neurons receive more robust excitatory inputs to their perisoma than does the pyramidal neuron. Notably, excitatory synapses on GABAergic neurons were often multiple-synapse boutons, making another synapse on distal dendrites. On the other hand, inhibitory synapses near the soma were often single-targeting multiple boutons. Collectively, our data demonstrate that synaptic inputs near the soma are differentially organized across cell types and form a network that balances inhibition and excitation in the V1.


Assuntos
Neurônios GABAérgicos/ultraestrutura , Células Piramidais/ultraestrutura , Sinapses/ultraestrutura , Córtex Visual/ultraestrutura , Animais , Neurônios GABAérgicos/metabolismo , Imageamento Tridimensional , Camundongos , Microscopia Eletrônica de Varredura , Parvalbuminas/metabolismo , Células Piramidais/metabolismo , Somatostatina/metabolismo
7.
J Cross Cult Gerontol ; 36(1): 21-42, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33141375

RESUMO

This study examined built environmental and socio-demographic variables as correlates of sedentary behaviour in a population of older adults, and attempted to introduce the idea of measuring sedentary behaviour with two domains, namely 'partial sedentary behaviour' and 'absolute sedentary behaviour'. The study's population was community-dwelling older adults aged 60 years or more in Accra, Ghana. A self-reported questionnaire was used to gather data from 504 older people. Multiple linear regression analysis was used to present findings, with all nominal categorical variables incorporated in this analysis dummy-coded. The overall (third) regression model accounted for a variance of 55.9% and a significant F-test [F (25,454) = 22.99; p < 0.001)]. Gender was positively associated with sedentary behaviour - the sedentary behaviour of women was 28 min in excess of that of men. Sedentary behaviour decreased as the social network size and supporting social network of older people increased. Sedentary behaviour decreased as availability of spacious road pavements, secure social recreational centres for older people, and health services in the community increased. The improvement of road safety conditions at the community level and design of the built environment to support social integration of older people are major recommendations of this study.


Assuntos
Ambiente Construído , Características de Residência/estatística & dados numéricos , Comportamento Sedentário , Meio Social , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Estudos Transversais , Feminino , Gana , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , Autorrelato , Fatores Socioeconômicos , Inquéritos e Questionários
8.
Int J Sport Nutr Exerc Metab ; 30(6): 427-434, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32932231

RESUMO

This study aimed to identify the acute effects of caffeinated chewing gum (CAF) on bicycle motocross (BMX) time-trial (TT) performance. In a randomized, placebo-controlled, double-blind cross-over design, 14 male BMX riders (age = 20.0 ± 3.3 years; height = 1.78 ± 0.04 m; body mass = 72 ± 4 kg), consumed either (300 mg; 4.2 ± 0.2 mg/kg) caffeinated (300 mg caffeine, 6 g sugars) or a placebo (0 mg caffeine, 0 g sugars) gum, and undertook three BMX TTs. Repeated-measure analysis revealed that CAF has a large ergogenic effect on TT time, F(1, 14) = 33.570, p = .001, ηp2=.71; -1.5% ± 0.4 compared with the placebo. Peak power and maximal power to weight ratio also increased significantly compared with the placebo condition, F(1, 14) = 54.666, p = .001, ηp2=.79; +3.5% ± 0.6, and F(1, 14) = 57.399, p = .001, ηp2=.80; +3% ± 0.3, respectively. Rating of perceived exertion was significantly lower F(1, 14) = 25.020, p = .001, ηp2=.64 in CAF (6.6 ± 1.3) compared with the placebo (7.2 ± 1.7). Administering a moderate dose (300 mg) of CAF could improve TT time by enhancing power and reducing the perception of exertion. BMX coaches and riders may consider consuming CAF before a BMX race to improve performance and reduce rating of perceived exertion.

9.
Cereb Cortex ; 27(7): 3869-3878, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28444185

RESUMO

Neurons process information through spatiotemporal integration of synaptic input. Synaptic transmission between any given pair of neurons is typically a dynamic process with presynaptic action potentials (APs) evoking depressing or facilitating postsynaptic potentials when presynaptic APs occur within hundreds of milliseconds of each other. In order to understand neocortical function, it is therefore important to investigate such short-term synaptic plasticity at synapses between different types of neocortical neurons. Here, we examine short-term synaptic dynamics between excitatory neurons in different layers of the mouse C2 barrel column through in vitro whole-cell recordings. We find layer-dependent short-term plasticity, with depression being dominant at many synaptic connections. Interestingly, however, presynaptic layer 2 neurons predominantly give rise to facilitating excitatory synaptic output at short interspike intervals of 10 and 30 ms. Previous studies have found prominent burst firing of excitatory neurons in supragranular layers of awake mice. The facilitation we observed in the synaptic output of layer 2 may, therefore, be functionally relevant, possibly serving to enhance the postsynaptic impact of burst firing.


Assuntos
Rede Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Córtex Somatossensorial/citologia , Animais , Biofísica , Estimulação Elétrica , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Patch-Clamp , Sinapses/fisiologia , Fatores de Tempo
10.
J Neurosci ; 35(41): 13896-903, 2015 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-26468190

RESUMO

The basal forebrain (BF) houses major ascending projections to the entire neocortex that have long been implicated in arousal, learning, and attention. The disruption of the BF has been linked with major neurological disorders, such as coma and Alzheimer's disease, as well as in normal cognitive aging. Although it is best known for its cholinergic neurons, the BF is in fact an anatomically and neurochemically complex structure. Recent studies using transgenic mouse lines to target specific BF cell types have led to a renaissance in the study of the BF and are beginning to yield new insights about cell-type-specific circuit mechanisms during behavior. These approaches enable us to determine the behavioral conditions under which cholinergic and noncholinergic BF neurons are activated and how they control cortical processing to influence behavior. Here we discuss recent advances that have expanded our knowledge about this poorly understood brain region and laid the foundation for future cell-type-specific manipulations to modulate arousal, attention, and cortical plasticity in neurological disorders. SIGNIFICANCE STATEMENT: Although the basal forebrain is best known for, and often equated with, acetylcholine-containing neurons that provide most of the cholinergic innervation of the neocortex, it is in fact an anatomically and neurochemically complex structure. Recent studies using transgenic mouse lines to target specific cell types in the basal forebrain have led to a renaissance in this field and are beginning to dissect circuit mechanisms in the basal forebrain during behavior. This review discusses recent advances in the roles of basal forebrain cholinergic and noncholinergic neurons in cognition via their dynamic modulation of cortical activity.


Assuntos
Prosencéfalo Basal/citologia , Prosencéfalo Basal/fisiologia , Cognição/fisiologia , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Optogenética/métodos , Animais , Humanos
11.
Eur J Neurosci ; 41(3): 354-67, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25476605

RESUMO

Mice can gather tactile sensory information by actively moving their whiskers to palpate objects in their immediate surroundings. Whisker sensory perception therefore requires integration of sensory and motor information, which occurs prominently in the neocortex. The signalling pathways from the neocortex for controlling whisker movements are currently poorly understood in mice. Here, we delineate two pathways, one originating from primary whisker somatosensory cortex (wS1) and the other from whisker motor cortex (wM1), that control qualitatively distinct movements of contralateral whiskers. Optogenetic stimulation of wS1 drove retraction of contralateral whiskers while stimulation of wM1 drove rhythmic whisker protraction. To map brainstem pathways connecting these cortical areas to whisker motor neurons, we used a combination of anterograde tracing using adenoassociated virus injected into neocortex and retrograde tracing using monosynaptic rabies virus injected into whisker muscles. Our data are consistent with wS1 driving whisker retraction by exciting glutamatergic premotor neurons in the rostral spinal trigeminal interpolaris nucleus, which in turn activate the motor neurons innervating the extrinsic retractor muscle nasolabialis. The rhythmic whisker protraction evoked by wM1 stimulation might be driven by excitation of excitatory and inhibitory premotor neurons in the brainstem reticular formation innervating both intrinsic and extrinsic muscles. Our data therefore begin to unravel the neuronal circuits linking the neocortex to whisker motor neurons.


Assuntos
Atividade Motora/fisiologia , Córtex Motor/anatomia & histologia , Córtex Somatossensorial/anatomia & histologia , Vibrissas/inervação , Animais , Axônios/fisiologia , Vias Eferentes/anatomia & histologia , Vias Eferentes/fisiologia , Feminino , Lateralidade Funcional/fisiologia , Ácido Glutâmico/metabolismo , Masculino , Camundongos Transgênicos , Córtex Motor/fisiologia , Neurônios Motores/citologia , Neurônios Motores/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Inibição Neural/fisiologia , Periodicidade , Formação Reticular/anatomia & histologia , Formação Reticular/fisiologia , Córtex Somatossensorial/fisiologia , Núcleo Espinal do Trigêmeo/anatomia & histologia , Núcleo Espinal do Trigêmeo/fisiologia , Vibrissas/fisiologia
12.
Adv Exp Med Biol ; 859: 273-96, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26238057

RESUMO

The development of functional imaging techniques applicable to neuroscience and covering a wide range of spatial and temporal scales has greatly facilitated the exploration of the relationships between cognition, behaviour and electrical brain activity. For mammals, the neocortex plays a particularly profound role in generating sensory perception, controlling voluntary movement, higher cognitive functions and planning goal-directed behaviours. Since these remarkable functions of the neocortex cannot be explored in simple model preparations or in anesthetised animals, the neural basis of behaviour must be explored in awake behaving subjects. Because neocortical function is highly distributed across many rapidly interacting regions, it is essential to measure spatiotemporal dynamics of cortical activity in real-time. Extensive work in anesthetised mammals has shown that in vivo Voltage-Sensitive Dye Imaging (VSDI) reveals the neocortical population membrane potential dynamics at millisecond temporal resolution and subcolumnar spatial resolution. Here, we describe recent advances indicating that VSDI is also already well-developed for exploring cortical function in behaving monkeys and mice. The first animal model, the non-human primate, is well-suited for fundamental exploration of higher-level cognitive function and behavior. The second animal model, the mouse, benefits from a rich arsenal of molecular and genetic technologies. In the monkey, imaging from the same patch of cortex, repeatedly, is feasible for a long period of time, up to a year. In the rodent, VSDI is applicable to freely moving and awake head-restrained mice. Interactions between different cortical areas and different cortical columns can therefore now be dynamically mapped through VSDI and related to the corresponding behaviour. Thus by applying VSDI to mice and monkeys one can begin to explore how behaviour emerges from neuronal activity in neuronal networks residing in different cortical areas.


Assuntos
Corantes Fluorescentes/química , Atividade Motora/fisiologia , Neocórtex/fisiologia , Neurônios/fisiologia , Sinapses/fisiologia , Potenciais Sinápticos/fisiologia , Imagens com Corantes Sensíveis à Voltagem/métodos , Animais , Mapeamento Encefálico , Potenciais Evocados Visuais/fisiologia , Macaca , Camundongos , Microeletrodos , Neocórtex/ultraestrutura , Rede Nervosa/fisiologia , Rede Nervosa/ultraestrutura , Neurônios/ultraestrutura , Análise Espaço-Temporal , Sinapses/ultraestrutura , Imagens com Corantes Sensíveis à Voltagem/instrumentação
13.
J Neurophysiol ; 112(8): 1801-14, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24944218

RESUMO

Uniform random sparse network architectures are ubiquitous in computational neuroscience, but the implicit hypothesis that they are a good representation of real neuronal networks has been met with skepticism. Here we used two experimental data sets, a study of triplet connectivity statistics and a data set measuring neuronal responses to channelrhodopsin stimuli, to evaluate the fidelity of thousands of model networks. Network architectures comprised three neuron types (excitatory, fast spiking, and nonfast spiking inhibitory) and were created from a set of rules that govern the statistics of the resulting connection types. In a high-dimensional parameter scan, we varied the degree distributions (i.e., how many cells each neuron connects with) and the synaptic weight correlations of synapses from or onto the same neuron. These variations converted initially uniform random and homogeneously connected networks, in which every neuron sent and received equal numbers of synapses with equal synaptic strength distributions, to highly heterogeneous networks in which the number of synapses per neuron, as well as average synaptic strength of synapses from or to a neuron were variable. By evaluating the impact of each variable on the network structure and dynamics, and their similarity to the experimental data, we could falsify the uniform random sparse connectivity hypothesis for 7 of 36 connectivity parameters, but we also confirmed the hypothesis in 8 cases. Twenty-one parameters had no substantial impact on the results of the test protocols we used.


Assuntos
Córtex Cerebral/fisiologia , Modelos Neurológicos , Rede Nervosa/fisiologia , Redes Neurais de Computação , Potenciais de Ação , Animais , Simulação por Computador , Interpretação Estatística de Dados , Humanos , Neurônios/fisiologia , Optogenética , Sinapses/fisiologia
14.
Nature ; 454(7206): 881-5, 2008 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-18633351

RESUMO

Internal brain states form key determinants for sensory perception, sensorimotor coordination and learning. A prominent reflection of different brain states in the mammalian central nervous system is the presence of distinct patterns of cortical synchrony, as revealed by extracellular recordings of the electroencephalogram, local field potential and action potentials. Such temporal correlations of cortical activity are thought to be fundamental mechanisms of neuronal computation. However, it is unknown how cortical synchrony is reflected in the intracellular membrane potential (V(m)) dynamics of behaving animals. Here we show, using dual whole-cell recordings from layer 2/3 primary somatosensory barrel cortex in behaving mice, that the V(m) of nearby neurons is highly correlated during quiet wakefulness. However, when the mouse is whisking, an internally generated state change reduces the V(m) correlation, resulting in a desynchronized local field potential and electroencephalogram. Action potential activity was sparse during both quiet wakefulness and active whisking. Single action potentials were driven by a large, brief and specific excitatory input that was not present in the V(m) of neighbouring cells. Action potential initiation occurs with a higher signal-to-noise ratio during active whisking than during quiet periods. Therefore, we show that an internal brain state dynamically regulates cortical membrane potential synchrony during behaviour and defines different modes of cortical processing.


Assuntos
Comportamento Exploratório/fisiologia , Potenciais da Membrana/fisiologia , Neurônios/fisiologia , Córtex Somatossensorial/fisiologia , Vigília/fisiologia , Animais , Eletroencefalografia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
15.
Cell Rep ; 43(1): 113618, 2024 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-38150365

RESUMO

Goal-directed behaviors involve coordinated activity in many cortical areas, but whether the encoding of task variables is distributed across areas or is more specifically represented in distinct areas remains unclear. Here, we compared representations of sensory, motor, and decision information in the whisker primary somatosensory cortex, medial prefrontal cortex, and tongue-jaw primary motor cortex in mice trained to lick in response to a whisker stimulus with mice that were not taught this association. Irrespective of learning, properties of the sensory stimulus were best encoded in the sensory cortex, whereas fine movement kinematics were best represented in the motor cortex. However, movement initiation and the decision to lick in response to the whisker stimulus were represented in all three areas, with decision neurons in the medial prefrontal cortex being more selective, showing minimal sensory responses in miss trials and motor responses during spontaneous licks. Our results reconcile previous studies indicating highly specific vs. highly distributed sensorimotor processing.


Assuntos
Neocórtex , Córtex Somatossensorial , Camundongos , Animais , Córtex Somatossensorial/fisiologia , Objetivos , Lobo Parietal , Neurônios , Vibrissas/fisiologia
16.
Nat Rev Neurosci ; 9(7): 557-68, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18568015

RESUMO

Neuroscience produces a vast amount of data from an enormous diversity of neurons. A neuronal classification system is essential to organize such data and the knowledge that is derived from them. Classification depends on the unequivocal identification of the features that distinguish one type of neuron from another. The problems inherent in this are particularly acute when studying cortical interneurons. To tackle this, we convened a representative group of researchers to agree on a set of terms to describe the anatomical, physiological and molecular features of GABAergic interneurons of the cerebral cortex. The resulting terminology might provide a stepping stone towards a future classification of these complex and heterogeneous cells. Consistent adoption will be important for the success of such an initiative, and we also encourage the active involvement of the broader scientific community in the dynamic evolution of this project.


Assuntos
Córtex Cerebral/citologia , Interneurônios , Ácido gama-Aminobutírico/metabolismo , Potenciais de Ação , Axônios/ultraestrutura , Córtex Cerebral/metabolismo , Humanos , Interneurônios/classificação , Interneurônios/citologia , Interneurônios/metabolismo , Sinapses/ultraestrutura
17.
PLoS One ; 18(6): e0287174, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37311008

RESUMO

Neocortical neurons can increasingly be divided into well-defined classes, but their activity patterns during quantified behavior remain to be fully determined. Here, we obtained membrane potential recordings from various classes of excitatory and inhibitory neurons located across different cortical depths in the primary whisker somatosensory barrel cortex of awake head-restrained mice during quiet wakefulness, free whisking and active touch. Excitatory neurons, especially those located superficially, were hyperpolarized with low action potential firing rates relative to inhibitory neurons. Parvalbumin-expressing inhibitory neurons on average fired at the highest rates, responding strongly and rapidly to whisker touch. Vasoactive intestinal peptide-expressing inhibitory neurons were excited during whisking, but responded to active touch only after a delay. Somatostatin-expressing inhibitory neurons had the smallest membrane potential fluctuations and exhibited hyperpolarising responses at whisking onset for superficial, but not deep, neurons. Interestingly, rapid repetitive whisker touch evoked excitatory responses in somatostatin-expressing inhibitory neurons, but not when the intercontact interval was long. Our analyses suggest that distinct genetically-defined classes of neurons at different subpial depths have differential activity patterns depending upon behavioral state providing a basis for constraining future computational models of neocortical function.


Assuntos
Tato , Vibrissas , Animais , Potenciais da Membrana , Neurônios , Somatostatina
18.
JMIR Res Protoc ; 12: e44940, 2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36867455

RESUMO

BACKGROUND: Unmet pediatric mental health (MH) needs are growing as rates of pediatric depression and anxiety dramatically increase. Access to care is limited by multiple factors, including a shortage of clinicians trained in developmentally specific, evidence-based services. Novel approaches to MH care delivery, including technology-leveraged and readily accessible options, need to be evaluated in service of expanding evidence-based services to youths and their families. Preliminary evidence supports the use of Woebot, a relational agent that digitally delivers guided cognitive behavioral therapy (CBT) through a mobile app, for adults with MH concerns. However, no studies have evaluated the feasibility and acceptability of such app-delivered relational agents specifically for adolescents with depression and/or anxiety within an outpatient MH clinic, nor compared them to other MH support services. OBJECTIVE: This paper describes the protocol for a randomized controlled trial evaluating the feasibility and acceptability of an investigational device, Woebot for Adolescents (W-GenZD), within an outpatient MH clinic for youths presenting with depression and/or anxiety. The study's secondary aim will compare the clinical outcomes of self-reported depressive symptoms with W-GenZD and a telehealth-delivered CBT-based skills group (CBT-group). Tertiary aims will evaluate additional clinical outcomes and therapeutic alliance between adolescents in W-GenZD and the CBT-group. METHODS: Participants include youths aged 13-17 years with depression and/or anxiety seeking care from an outpatient MH clinic at a children's hospital. Eligible youths will have no recent safety concerns or complex comorbid clinical diagnoses; have no concurrent individual therapy; and, if on medications, are on stable doses, based on clinical screening and as well as study-specific criteria. RESULTS: Recruitment began in May 2022. As of December 8, 2022, we have randomized 133 participants. CONCLUSIONS: Establishing the feasibility and acceptability of W-GenZD within an outpatient MH clinical setting will add to the field's current understanding of the utility and implementation considerations of this MH care service modality. The study will also evaluate the noninferiority of W-GenZD against the CBT-group. Findings may also have implications for patients, families, and providers looking for additional MH support options for adolescents seeking help for their depression and/or anxiety. Such options expand the menu of supports for youths with lower-intensity needs as well as possibly reduce waitlists and optimize clinician deployment toward more severe cases. TRIAL REGISTRATION: ClinicalTrials.gov NCT05372913; https://clinicaltrials.gov/ct2/show/NCT05372913. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/44940.

19.
Function (Oxf) ; 4(6): zqad056, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37841525

RESUMO

We are constantly bombarded by sensory information and constantly making decisions on how to act. In order to optimally adapt behavior, we must judge which sequences of sensory inputs and actions lead to successful outcomes in specific circumstances. Neuronal circuits of the basal ganglia have been strongly implicated in action selection, as well as the learning and execution of goal-directed behaviors, with accumulating evidence supporting the hypothesis that midbrain dopamine neurons might encode a reward signal useful for learning. Here, we review evidence suggesting that midbrain dopaminergic neurons signal reward prediction error, driving synaptic plasticity in the striatum underlying learning. We focus on phasic increases in action potential firing of midbrain dopamine neurons in response to unexpected rewards. These dopamine neurons prominently innervate the dorsal and ventral striatum. In the striatum, the released dopamine binds to dopamine receptors, where it regulates the plasticity of glutamatergic synapses. The increase of striatal dopamine accompanying an unexpected reward activates dopamine type 1 receptors (D1Rs) initiating a signaling cascade that promotes long-term potentiation of recently active glutamatergic input onto striatonigral neurons. Sensorimotor-evoked glutamatergic input, which is active immediately before reward delivery will thus be strengthened onto neurons in the striatum expressing D1Rs. In turn, these neurons cause disinhibition of brainstem motor centers and disinhibition of the motor thalamus, thus promoting motor output to reinforce rewarded stimulus-action outcomes. Although many details of the hypothesis need further investigation, altogether, it seems likely that dopamine signals in the striatum might underlie important aspects of goal-directed reward-based learning.


Assuntos
Dopamina , Estriado Ventral , Dopamina/metabolismo , Aprendizagem , Recompensa , Neurônios Dopaminérgicos/metabolismo , Estriado Ventral/metabolismo
20.
Curr Biol ; 33(16): 3436-3451.e7, 2023 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-37536343

RESUMO

During reward-based learning tasks, animals make orofacial movements that globally influence brain activity at the timings of reward expectation and acquisition. These orofacial movements are not explicitly instructed and typically appear along with goal-directed behaviors. Here, we show that reinforcing optogenetic stimulation of dopamine neurons in the ventral tegmental area (oDAS) in mice is sufficient to induce orofacial movements in the whiskers and nose without accompanying goal-directed behaviors. Pavlovian conditioning with a sensory cue and oDAS elicited cue-locked and oDAS-aligned orofacial movements, which were distinguishable by a machine-learning model. Inhibition or knockout of dopamine D1 receptors in the nucleus accumbens inhibited oDAS-induced motion but spared cue-locked motion, suggesting differential regulation of these two types of orofacial motions. In contrast, inactivation of the whisker primary motor cortex (wM1) abolished both types of orofacial movements. We found specific neuronal populations in wM1 representing either oDAS-aligned or cue-locked whisker movements. Notably, optogenetic stimulation of wM1 neurons successfully replicated these two types of movements. Our results thus suggest that accumbal D1-receptor-dependent and -independent neuronal signals converge in the wM1 for facilitating distinct uninstructed orofacial movements during a reward-based learning task.


Assuntos
Núcleo Accumbens , Área Tegmentar Ventral , Camundongos , Animais , Núcleo Accumbens/fisiologia , Área Tegmentar Ventral/fisiologia , Movimento , Neurônios Dopaminérgicos/fisiologia , Receptores de Dopamina D1 , Recompensa
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