Base de dados : MEDLINE
Pesquisa : A13.950 [Categoria DeCS]
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  1 / 2749 MEDLINE  
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[PMID]:29184204
[Au] Autor:Winder AT; Echagarruga C; Zhang Q; Drew PJ
[Ad] Endereço:Center for Neural Engineering, Pennsylvania State University, University Park, PA, USA.
[Ti] Título:Weak correlations between hemodynamic signals and ongoing neural activity during the resting state.
[So] Source:Nat Neurosci;20(12):1761-1769, 2017 Dec.
[Is] ISSN:1546-1726
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Spontaneous fluctuations in hemodynamic signals in the absence of a task or overt stimulation are used to infer neural activity. We tested this coupling by simultaneously measuring neural activity and changes in cerebral blood volume (CBV) in the somatosensory cortex of awake, head-fixed mice during periods of true rest and during whisker stimulation and volitional whisking. We found that neurovascular coupling was similar across states and that large, spontaneous CBV changes in the absence of sensory input were driven by volitional whisker and body movements. Hemodynamic signals during periods of rest were weakly correlated with neural activity. Spontaneous fluctuations in CBV and vessel diameter persisted when local neural spiking and glutamatergic input were blocked, as well as during blockade of noradrenergic receptors, suggesting a non-neuronal origin for spontaneous CBV fluctuations. Spontaneous hemodynamic signals reflect a combination of behavior, local neural activity, and putatively non-neural processes.
[Mh] Termos MeSH primário: Hemodinâmica/fisiologia
Descanso/fisiologia
[Mh] Termos MeSH secundário: Animais
Comportamento Animal/fisiologia
Volume Sanguíneo
Circulação Cerebrovascular/fisiologia
Nervo Facial/fisiologia
Imagem por Ressonância Magnética
Masculino
Camundongos
Camundongos Endogâmicos C57BL
Movimento/fisiologia
Fenômenos Fisiológicos do Sistema Nervoso
Estimulação Luminosa
Córtex Somatossensorial/irrigação sanguínea
Vibrissas/inervação
Vibrissas/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1712
[Cu] Atualização por classe:180220
[Lr] Data última revisão:
180220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171130
[St] Status:MEDLINE
[do] DOI:10.1038/s41593-017-0007-y


  2 / 2749 MEDLINE  
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[PMID]:29267341
[Au] Autor:Abe K; Yawo H
[Ad] Endereço:Department of Development Biology and Neuroscience, Tohoku University Graduate School of Life Science, Sendai, Japan.
[Ti] Título:Optogenetic conditioning of paradigm and pattern discrimination in the rat somatosensory system.
[So] Source:PLoS One;12(12):e0189439, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The rodent whisker-barrel cortical system is a model for studying somatosensory discrimination at high spatiotemporal precision. Here, we applied optogenetics to produce somatosensory inputs in the whisker area using one of transgenic rat lines, W-TChR2V4, which expresses channelrhodopsin-2 (ChR2) in the mechanoreceptive nerve endings around whisker follicles. An awake W-TChR2V4 rat was head-fixed and irradiated by blue LED light on the whisker area with a paradigm conditioned with a reward. The Go task was designed so the rat is allowed to receive a reward, when it licked the nozzle within 5 s after photostimulation. The No-go task was designed so as the rat has to withhold licking for at least 5 s to obtain a reward after photostimulation. The Go-task conditioning was established within 1 hr of training with a reduction in the reaction time and increase of the success rate. To investigate the relationship between the spatiotemporal pattern of sensory inputs and the behavioral output, we designed a multi-optical fiber system that irradiates the whisker area at 9 spots in a 3×3 matrix. Although the Go-task conditioning was established using synchronous irradiation of 9 spots, the success rate was decreased with an increase of the reaction time for the asynchronous irradiation. After conditioning to the Go task, the rat responded to the blue LED flash irradiated on the barrel cortex, where many neurons also express ChR2, or photostimulation of the contralateral whisker area with a similar reaction time and success rate. Synchronous activation of the peripheral mechanoreceptive nerves is suggested to drive a neural circuit in the somatosensory cortex that efficiently couples with the decision. Our optogenetic system would enable the precise evaluation of the psychophysical values, such as the reaction time and success rate, to gain some insight into the brain mechanisms underlying conditioned behaviors.
[Mh] Termos MeSH primário: Optogenética
Córtex Somatossensorial/fisiologia
Vibrissas/fisiologia
[Mh] Termos MeSH secundário: Animais
Comportamento Animal
Condicionamento Operante
Ratos
Ratos Transgênicos
Tempo de Reação
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180116
[Lr] Data última revisão:
180116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171222
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0189439


  3 / 2749 MEDLINE  
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[PMID]:29176874
[Au] Autor:Reyes-Corona D; Vázquez-Hernández N; Escobedo L; Orozco-Barrios CE; Ayala-Davila J; Moreno MG; Amaro-Lara ME; Flores-Martinez YM; Espadas-Alvarez AJ; Fernandez-Parrilla MA; Gonzalez-Barrios JA; Gutierrez-Castillo ME; González-Burgos I; Martinez-Fong D
[Ad] Endereço:Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados, Ciudad de México, México.
[Ti] Título:Neurturin overexpression in dopaminergic neurons induces presynaptic and postsynaptic structural changes in rats with chronic 6-hydroxydopamine lesion.
[So] Source:PLoS One;12(11):e0188239, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The structural effect of neurturin (NRTN) on the nigrostriatal dopaminergic system in animals remains unknown, although NRTN has been shown to be effective in Parkinson's disease animal models. Herein, we aimed to demonstrate that NRTN overexpression in dopaminergic neurons stimulates both neurite outgrowths in the nigrostriatal pathway and striatal dendritic spines in aging rats with chronic 6-hydroxydopamine (6-OHDA) lesion. At week 12 after lesion, pTracer-mNRTN-His or pGreenLantern-1 plasmids were intranigrally transfected using the NTS-polyplex nanoparticles system. We showed that the transgenic expression in dopaminergic neurons remained until the end of the study (12 weeks). Only animals expressing NRTN-His showed recovery of tyrosine hydroxylase (TH)+ cells (28 ± 2%), their neurites (32 ± 2%) and the neuron-specific cytoskeletal marker ß-III-tubulin in the substantia nigra; striatal TH(+) fibers were also recovered (52 ± 3%), when compared to the healthy condition. Neurotensin receptor type 1 levels were also significantly recovered in the substantia nigra and striatum. Dopamine recovery was 70 ± 4% in the striatum and complete in the substantia nigra. The number of dendritic spines of striatal medium spiny neurons was also significantly increased, but the recovery was not complete. Drug-activated circling behavior decreased by 73 ± 2% (methamphetamine) and 89 ± 1% (apomorphine). Similar decrease was observed in the spontaneous motor behavior. Our results demonstrate that NRTN causes presynaptic and postsynaptic restoration of the nigrostriatal dopaminergic system after a 6-OHDA-induced chronic lesion. However, those improvements did not reach the healthy condition, suggesting that NRTN exerts lesser neurotrophic effects than other neurotrophic approaches.
[Mh] Termos MeSH primário: Neurônios Dopaminérgicos/metabolismo
Neurturina/metabolismo
Terminações Pré-Sinápticas/metabolismo
[Mh] Termos MeSH secundário: Animais
Corpo Estriado/metabolismo
Corpo Estriado/patologia
Citoesqueleto/metabolismo
Espinhas Dendríticas/metabolismo
Dopamina/metabolismo
Ensaio de Imunoadsorção Enzimática
Membro Anterior/fisiologia
Masculino
Camundongos
Neuritos/metabolismo
Oxidopamina
Ratos Wistar
Receptores de Neurotensina/metabolismo
Substância Negra/metabolismo
Substância Negra/patologia
Transfecção
Vibrissas/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Neurturin); 0 (Receptors, Neurotensin); 0 (neurotensin type 1 receptor); 8HW4YBZ748 (Oxidopamine); VTD58H1Z2X (Dopamine)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171219
[Lr] Data última revisão:
171219
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171128
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0188239


  4 / 2749 MEDLINE  
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[PMID]:28899918
[Au] Autor:Liu C; Foffani G; Scaglione A; Aguilar J; Moxon KA
[Ad] Endereço:School of Biomedical Engineering, Science and Health System, Drexel University, Philadelphia, Pennsylvania 19104.
[Ti] Título:Adaptation of Thalamic Neurons Provides Information about the Spatiotemporal Context of Stimulus History.
[So] Source:J Neurosci;37(41):10012-10021, 2017 Oct 11.
[Is] ISSN:1529-2401
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Adaptation of neural responses due to the history of sensory input has been observed across all sensory modalities. However, the computational role of adaptation is not fully understood, especially when one considers neural coding problems in which adaptation increases the ambiguity of the neural responses to simple stimuli. To address this, we quantified the impact of adaptation on the information conveyed by thalamic neurons about paired whisker stimuli in male rat. At the single neuron level, although paired-pulse adaptation reduces the information about the present stimulus, the information per spike increases. Moreover, the adapted response can convey significant amounts of information about whether, when and where a previous stimulus occurred. At the population level, ambiguity of the adapted responses about the present stimulus can be compensated for by large numbers of neurons. Therefore, paired-pulse adaptation does not reduce the discriminability of simple stimuli. It provides information about the spatiotemporal context of stimulus history. The present work provides a computational framework that demonstrates how adaptation allows neurons to encode spatiotemporal dynamics of stimulus history.
[Mh] Termos MeSH primário: Adaptação Fisiológica/fisiologia
Neurônios/fisiologia
Tálamo/fisiologia
[Mh] Termos MeSH secundário: Animais
Estimulação Elétrica
Masculino
Ratos
Ratos Wistar
Percepção Espacial/fisiologia
Tálamo/citologia
Vibrissas/inervação
Vibrissas/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170914
[St] Status:MEDLINE
[do] DOI:10.1523/JNEUROSCI.0637-17.2017


  5 / 2749 MEDLINE  
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[PMID]:28735746
[Au] Autor:Bellavance MA; Takatoh J; Lu J; Demers M; Kleinfeld D; Wang F; Deschênes M
[Ad] Endereço:Department of Psychiatry and Neuroscience, Laval University, Québec City, QC G1J 2G3, Canada.
[Ti] Título:Parallel Inhibitory and Excitatory Trigemino-Facial Feedback Circuitry for Reflexive Vibrissa Movement.
[So] Source:Neuron;95(3):673-682.e4, 2017 Aug 02.
[Is] ISSN:1097-4199
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Animals employ active touch to optimize the acuity of their tactile sensors. Prior experimental results and models lead to the hypothesis that sensory inputs are used in a recurrent manner to tune the position of the sensors. A combination of electrophysiology, intersectional genetic viral labeling and manipulation, and classical tracing allowed us to identify second-order sensorimotor loops that control vibrissa movements by rodents. Facial motoneurons that drive intrinsic muscles to protract the vibrissae receive a short latency inhibitory input, followed by synaptic excitation, from neurons located in the oralis division of the trigeminal sensory complex. In contrast, motoneurons that retract the mystacial pad and indirectly retract the vibrissae receive only excitatory input from interpolaris cells that further project to the thalamus. Silencing this feedback alters retraction. The observed pull-push circuit at the lowest-level sensorimotor loop provides a mechanism for the rapid modulation of vibrissa touch during exploration of peri-personal space.
[Mh] Termos MeSH primário: Comportamento Animal/fisiologia
Tronco Encefálico/fisiologia
Retroalimentação
Movimento/fisiologia
Vibrissas/fisiologia
[Mh] Termos MeSH secundário: Animais
Feminino
Masculino
Camundongos
Neurônios Motores/metabolismo
Ratos Long-Evans
Tálamo/fisiologia
Tato/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170914
[Lr] Data última revisão:
170914
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170725
[St] Status:MEDLINE


  6 / 2749 MEDLINE  
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[PMID]:28700664
[Au] Autor:Sundberg JP; Dadras SS; Silva KA; Kennedy VE; Garland G; Murray SA; Sundberg BA; Schofield PN; Pratt CH
[Ad] Endereço:The Jackson Laboratory, Bar Harbor, Maine, United States of America.
[Ti] Título:Systematic screening for skin, hair, and nail abnormalities in a large-scale knockout mouse program.
[So] Source:PLoS One;12(7):e0180682, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The International Knockout Mouse Consortium was formed in 2007 to inactivate ("knockout") all protein-coding genes in the mouse genome in embryonic stem cells. Production and characterization of these mice, now underway, has generated and phenotyped 3,100 strains with knockout alleles. Skin and adnexa diseases are best defined at the gross clinical level and by histopathology. Representative retired breeders had skin collected from the back, abdomen, eyelids, muzzle, ears, tail, and lower limbs including the nails. To date, 169 novel mutant lines were reviewed and of these, only one was found to have a relatively minor sebaceous gland abnormality associated with follicular dystrophy. The B6N(Cg)-Far2tm2b(KOMP)Wtsi/2J strain, had lesions affecting sebaceous glands with what appeared to be a secondary follicular dystrophy. A second line, B6N(Cg)-Ppp1r9btm1.1(KOMP)Vlcg/J, had follicular dystrophy limited to many but not all mystacial vibrissae in heterozygous but not homozygous mutant mice, suggesting that this was a nonspecific background lesion. We discuss potential reasons for the low frequency of skin and adnexal phenotypes in mice from this project in comparison to those seen in human Mendelian diseases, and suggest alternative approaches to identification of human disease-relevant models.
[Mh] Termos MeSH primário: Cabelo/anormalidades
Unhas Malformadas/genética
Anormalidades da Pele/genética
[Mh] Termos MeSH secundário: Animais
Camundongos Endogâmicos C57BL
Camundongos Knockout
Glândulas Sebáceas/patologia
Pele/patologia
Vibrissas/patologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170925
[Lr] Data última revisão:
170925
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170713
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0180682


  7 / 2749 MEDLINE  
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[PMID]:28663199
[Au] Autor:Tsytsarev V; Arakawa H; Zhao S; Chédotal A; Erzurumlu RS
[Ad] Endereço:Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and.
[Ti] Título:Behavioral Consequences of a Bifacial Map in the Mouse Somatosensory Cortex.
[So] Source:J Neurosci;37(30):7209-7218, 2017 Jul 26.
[Is] ISSN:1529-2401
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The whisker system is an important sensory organ with extensive neural representations in the brain of the mouse. Patterned neural modules (barrelettes) in the ipsilateral principal sensory nucleus of the trigeminal nerve (PrV) correspond to the whiskers. Axons of the PrV barrelette neurons cross the midline and confer the whisker-related patterning to the contralateral ventroposteromedial nucleus of the thalamus, and subsequently to the cortex. In this way, specific neural modules called barreloids and barrels in the contralateral thalamus and cortex represent each whisker. Partial midline crossing of the PrV axons, in a conditional Robo3 mutant ( ) mouse line, leads to the formation of bilateral whisker maps in the ventroposteromedial, as well as the barrel cortex. We used voltage-sensitive dye optical imaging and somatosensory and motor behavioral tests to characterize the consequences of bifacial maps in the thalamocortical system. Voltage-sensitive dye optical imaging verified functional, bilateral whisker representation in the barrel cortex and activation of distinct cortical loci following ipsilateral and contralateral stimulation of the specific whiskers. The mutant animals were comparable with the control animals in sensorimotor tests. However, they showed noticeable deficits in all of the whisker-dependent or -related tests, including Y-maze exploration, horizontal surface approach, bridge crossing, gap crossing, texture discrimination, floating in water, and whisking laterality. Our results indicate that bifacial maps along the thalamocortical system do not offer a functional advantage. Instead, they lead to impairments, possibly due to the smaller size of the whisker-related modules and interference between the ipsilateral and contralateral whisker representations in the same thalamus and cortex. The whisker sensory system plays a quintessentially important role in exploratory behavior of mice and other nocturnal rodents. Here, we studied a novel mutant mouse line, in which the projections from the brainstem to the thalamus are disrupted. This led to formation of bilateral whisker maps in both the thalamus and the cortex. The two whisker maps crowd in a space normally devoted to the contralateral map alone and in a nonoverlapping fashion. Stimulation of the whiskers on either side activates the corresponding region of the map. Mice with bilateral whisker maps perform well in general sensorimotor tasks but show poor performance in specific tests that require whisker-dependent tactile discrimination. These observations indicate that contralateral, instead of bilateral, representation of the sensory space plays a critical role in acuity and fine discrimination during somesthesis.
[Mh] Termos MeSH primário: Comportamento Animal/fisiologia
Comportamento Exploratório/fisiologia
Rede Nervosa/fisiologia
Córtex Somatossensorial/fisiologia
Tato/fisiologia
Vibrissas/fisiologia
[Mh] Termos MeSH secundário: Animais
Feminino
Masculino
Camundongos
Camundongos Endogâmicos C57BL
Camundongos Transgênicos
Desempenho Psicomotor/fisiologia
Vibrissas/inervação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170822
[Lr] Data última revisão:
170822
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170701
[St] Status:MEDLINE
[do] DOI:10.1523/JNEUROSCI.0598-17.2017


  8 / 2749 MEDLINE  
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[PMID]:28663200
[Au] Autor:Kerekes P; Daret A; Shulz DE; Ego-Stengel V
[Ad] Endereço:Unité de Neuroscience, Information et Complexité, Centre National de la Recherche Scientifique, FRE 3693, 91198 Gif-sur-Yvette, France.
[Ti] Título:Bilateral Discrimination of Tactile Patterns without Whisking in Freely Running Rats.
[So] Source:J Neurosci;37(32):7567-7579, 2017 Aug 09.
[Is] ISSN:1529-2401
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A majority of whisker discrimination tasks in rodents are performed on head-fixed animals to facilitate tracking or control of the sensory inputs. However, head fixation critically restrains the behavior and thus the incoming stimuli compared with those occurring in natural conditions. In this study, we investigated whether freely behaving rats can discriminate fine tactile patterns while running, in particular when stimuli are presented simultaneously on both sides of the snout. We developed a two-alternative forced-choice task in an automated modified T-maze. Stimuli were either a surface with no bars (smooth) or with vertical bars spaced irregularly or regularly. While running at full speed, rats encountered simultaneously the two discriminanda placed on the two sides of the central aisle. Rats learned to recognize regular bars versus a smooth surface in 8 weeks. They solved the task while running at an average speed of 1 m/s, so that the contact with the stimulus lasted <1 typical whisking cycle, precluding the use of active whisking. Whisker-tracking analysis revealed an asymmetry in the position of the whiskers: they oriented toward the rewarded stimulus during successful trials as early as 60 ms after the first possible contact. We showed that the whiskers and activity in the primary somatosensory cortex are involved during the discrimination process. Finally, we identified irregular patterns of bars that the rats can discriminate from the regular one. This novel task shows that freely moving rodents can make simultaneous bilateral tactile discrimination without whisking. The whisker system of rodents is a widely used model to study tactile processing. Rats show remarkable abilities in discriminating surfaces by actively moving their whiskers (whisking) against stimuli, typically sampling them several times. This motor strategy affects considerably the way that tactile information is acquired and thus the way that neuronal networks process the information. However, when rats run at high speed, they protract their whiskers in front of the snout without large movements. Here, we investigated whether rats are able to discriminate regular and irregular patterns of vertical bars while running without whisking. We found that the animals can perform a bilateral simultaneous discrimination without whisking and that this involves both whiskers and barrel cortex activity.
[Mh] Termos MeSH primário: Aprendizagem por Discriminação/fisiologia
Lateralidade Funcional/fisiologia
Córtex Somatossensorial/fisiologia
Tato/fisiologia
Vibrissas/fisiologia
[Mh] Termos MeSH secundário: Animais
Comportamento Exploratório/fisiologia
Masculino
Distribuição Aleatória
Ratos
Ratos Long-Evans
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170911
[Lr] Data última revisão:
170911
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170701
[St] Status:MEDLINE
[do] DOI:10.1523/JNEUROSCI.0528-17.2017


  9 / 2749 MEDLINE  
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[PMID]:28641104
[Au] Autor:Lee J; Barth AL
[Ad] Endereço:Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
[Ti] Título:Constructing the External World.
[So] Source:Neuron;94(6):1048-1050, 2017 Jun 21.
[Is] ISSN:1097-4199
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In this issue of Neuron, Pluta et al. (2017) find a novel map of external space in primary somatosensory cortex, generated by multi-whisker interactions during active touch.
[Mh] Termos MeSH primário: Córtex Somatossensorial
Vibrissas
[Mh] Termos MeSH secundário: Animais
Neurônios
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171026
[Lr] Data última revisão:
171026
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170623
[St] Status:MEDLINE


  10 / 2749 MEDLINE  
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[PMID]:28591219
[Au] Autor:Gutnisky DA; Yu J; Hires SA; To MS; Bale MR; Svoboda K; Golomb D
[Ad] Endereço:Janelia Research Campus, HHMI, Ashburn, Virginia, United States of America.
[Ti] Título:Mechanisms underlying a thalamocortical transformation during active tactile sensation.
[So] Source:PLoS Comput Biol;13(6):e1005576, 2017 Jun.
[Is] ISSN:1553-7358
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:During active somatosensation, neural signals expected from movement of the sensors are suppressed in the cortex, whereas information related to touch is enhanced. This tactile suppression underlies low-noise encoding of relevant tactile features and the brain's ability to make fine tactile discriminations. Layer (L) 4 excitatory neurons in the barrel cortex, the major target of the somatosensory thalamus (VPM), respond to touch, but have low spike rates and low sensitivity to the movement of whiskers. Most neurons in VPM respond to touch and also show an increase in spike rate with whisker movement. Therefore, signals related to self-movement are suppressed in L4. Fast-spiking (FS) interneurons in L4 show similar dynamics to VPM neurons. Stimulation of halorhodopsin in FS interneurons causes a reduction in FS neuron activity and an increase in L4 excitatory neuron activity. This decrease of activity of L4 FS neurons contradicts the "paradoxical effect" predicted in networks stabilized by inhibition and in strongly-coupled networks. To explain these observations, we constructed a model of the L4 circuit, with connectivity constrained by in vitro measurements. The model explores the various synaptic conductance strengths for which L4 FS neurons actively suppress baseline and movement-related activity in layer 4 excitatory neurons. Feedforward inhibition, in concert with recurrent intracortical circuitry, produces tactile suppression. Synaptic delays in feedforward inhibition allow transmission of temporally brief volleys of activity associated with touch. Our model provides a mechanistic explanation of a behavior-related computation implemented by the thalamocortical circuit.
[Mh] Termos MeSH primário: Modelos Neurológicos
Movimento/fisiologia
Rede Nervosa/fisiologia
Córtex Sensório-Motor/fisiologia
Tálamo/fisiologia
Tato/fisiologia
[Mh] Termos MeSH secundário: Vias Aferentes/fisiologia
Animais
Simulação por Computador
Potencial Evocado Motor/fisiologia
Potenciais Somatossensoriais Evocados/fisiologia
Camundongos
Plasticidade Neuronal/fisiologia
Vibrissas/inervação
Vibrissas/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170818
[Lr] Data última revisão:
170818
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170608
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pcbi.1005576



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BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde