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1.
Behav Neurosci ; 134(5): 369-383, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33001679

RESUMO

This study investigated whether the application of high definition transcranial DC stimulation (HD-tDCS) to the dorsolateral prefrontal cortex reduces cue-induced food craving when combined with food-specific inhibitory control training. Using a within-subjects design, participants (N = 55) received both active and sham HD-tDCS across 2 sessions while completing a Go/No-Go task in which foods were either associated with response inhibition or response execution. Food craving was measured pre and post stimulation using a standardized questionnaire as well as desire to eat ratings for foods associated with both response inhibition and response execution in the training task. Results revealed no effect of HD-tDCS on reducing state food craving or desire to eat. Due to the COVID-19 pandemic, we were unable to achieve our maximum preplanned sample size or our minimum desired Bayesian evidence strength across all a priori hypotheses; however 6 of the 7 hypotheses converged with moderate or stronger evidence in favor of the null hypothesis over the alternative hypothesis. We discuss the importance of individual differences and provide recommendations for future studies with an emphasis on the importance of cognitive interventions. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Assuntos
Fissura/fisiologia , Preferências Alimentares/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto , Teorema de Bayes , Estudos Cross-Over , Sinais (Psicologia) , Feminino , Alimentos , Humanos , Masculino , Inquéritos e Questionários , Estimulação Transcraniana por Corrente Contínua/métodos
2.
Nat Commun ; 11(1): 4728, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32963237

RESUMO

Social trust is linked to a host of positive societal outcomes, including improved economic performance, lower crime rates and more inclusive institutions. Yet, the origins of trust remain elusive, partly because social trust is difficult to document in time. Building on recent advances in social cognition, we design an algorithm to automatically generate trustworthiness evaluations for the facial action units (smile, eye brows, etc.) of European portraits in large historical databases. Our results show that trustworthiness in portraits increased over the period 1500-2000 paralleling the decline of interpersonal violence and the rise of democratic values observed in Western Europe. Further analyses suggest that this rise of trustworthiness displays is associated with increased living standards.


Assuntos
Sinais (Psicologia) , Face/anatomia & histologia , Expressão Facial , Aprendizado de Máquina , Algoritmos , Europa (Continente) , Feminino , Humanos , Masculino , Pinturas , Percepção Social , Confiança
3.
Proc Biol Sci ; 287(1934): 20201894, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32900312

RESUMO

Some camouflaged animals hide colour signals and display them only transiently. These hidden colour signals are often conspicuous and are used as a secondary defence to warn or startle predators (deimatic displays) and/or to confuse them (flash displays). The hidden signals used in these displays frequently resemble typical aposematic signals, so it is possible that prey with hidden signals have evolved to employ colour patterns of a form that predators have previously learned to associate with unprofitability. Here, we tested this hypothesis by conducting two experiments that examined the effect of predator avoidance learning on the efficacy of deimatic and flash displays. We found that the survival benefits of both deimatic and flash displays were substantially higher against predators that had previously learned to associate the hidden colours with unprofitability than against naive predators. These findings help explain the phenological patterns we found in 1568 macro-lepidopteran species on three continents: species with hidden signals tend to occur later in the season than species without hidden signals.


Assuntos
Aprendizagem da Esquiva , Pigmentação , Comportamento Predatório , Animais , Cor , Sinais (Psicologia) , Estações do Ano
5.
Nat Commun ; 11(1): 4634, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929078

RESUMO

The current opioid epidemic necessitates a better understanding of human addiction neurobiology to develop efficacious treatment approaches. Here, we perform genome-wide assessment of chromatin accessibility of the human striatum in heroin users and matched controls. Our study reveals distinct neuronal and non-neuronal epigenetic signatures, and identifies a locus in the proximity of the gene encoding tyrosine kinase FYN as the most affected region in neurons. FYN expression, kinase activity and the phosphorylation of its target Tau are increased by heroin use in the post-mortem human striatum, as well as in rats trained to self-administer heroin and primary striatal neurons treated with chronic morphine in vitro. Pharmacological or genetic manipulation of FYN activity significantly attenuates heroin self-administration and responding for drug-paired cues in rodents. Our findings suggest that striatal FYN is an important driver of heroin-related neurodegenerative-like pathology and drug-taking behavior, making FYN a promising therapeutic target for heroin use disorder.


Assuntos
Cromatina/metabolismo , Corpo Estriado/enzimologia , Dependência de Heroína/enzimologia , Terapia de Alvo Molecular , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Animais , Sequência de Bases , Comportamento Animal/efeitos dos fármacos , Sinais (Psicologia) , Genoma , Células HEK293 , Heroína/efeitos adversos , Humanos , Masculino , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas c-fyn/antagonistas & inibidores , Ratos Long-Evans , Autoadministração , Transcrição Genética/efeitos dos fármacos , Proteínas tau/metabolismo
6.
PLoS Comput Biol ; 16(9): e1008163, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32898146

RESUMO

Learning to avoid harmful consequences can be a costly trial-and-error process. In such situations, social information can be leveraged to improve individual learning outcomes. Here, we investigated how participants used their own experiences and others' social cues to avoid harm. Participants made repeated choices between harmful and safe options, each with different probabilities of generating shocks, while also seeing the image of a social partner. Some partners made predictive gaze cues towards the harmful choice option while others cued an option at random, and did so using neutral or fearful facial expressions. We tested how learned social information about partner reliability transferred across contexts by letting participants encounter the same partner in multiple trial blocks while facing novel choice options. Participants' decisions were best explained by a reinforcement learning model that independently learned the probabilities of options being safe and of partners being reliable and combined these combined these estimates to generate choices. Advice from partners making a fearful facial expression influenced participants' decisions more than advice from partners with neutral expressions. Our results showed that participants made better decisions when facing predictive partners and that they cached and transferred partner reliability estimates into new blocks. Using simulations we show that participants' transfer of social information into novel contexts is better adapted to variable social environments where social partners may change their cuing strategy or become untrustworthy. Finally, we found no relation between autism questionnaire scores and performance in our task, but do find autism trait related differences in learning rate parameters.


Assuntos
Aprendizagem da Esquiva/fisiologia , Condicionamento Operante/fisiologia , Comportamento Social , Comportamento de Escolha/fisiologia , Comunicação , Biologia Computacional , Sinais (Psicologia) , Fixação Ocular/fisiologia , Humanos
7.
Proc Natl Acad Sci U S A ; 117(33): 19825-19829, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32759213

RESUMO

Suppose you are surreptitiously looking at someone, and then when they catch you staring at them, you immediately turn away. This is a social phenomenon that almost everyone experiences occasionally. In such experiences-which we will call gaze deflection-the "deflected" gaze is not directed at anything in particular but simply away from the other person. As such, this is a rare instance where we may turn to look in a direction without intending to look there specifically. Here we show that gaze cues are markedly less effective at orienting an observer's attention when they are seen as deflected in this way-even controlling for low-level visual properties. We conclude that gaze cueing is a sophisticated mental phenomenon: It is not merely driven by perceived eye or head motions but is rather well tuned to extract the "mind" behind the eyes.


Assuntos
Atenção , Fenômenos Fisiológicos Oculares , Percepção Social , Adulto , Sinais (Psicologia) , Feminino , Humanos , Intenção , Orientação Espacial , Visão Ocular
8.
Nat Commun ; 11(1): 4182, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826882

RESUMO

Living in a group allows individuals to decrease their defenses, enabling other beneficial behaviors such as foraging. The detection of a threat through social cues is widely reported, however, the safety cues that guide animals to break away from a defensive behavior and resume alternate activities remain elusive. Here we show that fruit flies display a graded decrease in freezing behavior, triggered by an inescapable threat, with increasing group sizes. Furthermore, flies use the cessation of movement of other flies as a cue of threat and its resumption as a cue of safety. Finally, we find that lobula columnar neurons, LC11, mediate the propensity for freezing flies to resume moving in response to the movement of others. By identifying visual motion cues, and the neurons involved in their processing, as the basis of a social safety cue this study brings new insights into the neuronal basis of safety in numbers.


Assuntos
Comportamento Animal , Drosophila/fisiologia , Neurônios/fisiologia , Segurança , Comportamento Social , Animais , Sinais (Psicologia) , Feminino , Congelamento
9.
Nat Commun ; 11(1): 4220, 2020 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-32839437

RESUMO

Post-traumatic stress disorder (PTSD) is characterized by emotional hypermnesia on which preclinical studies focus so far. While this hypermnesia relates to salient traumatic cues, partial amnesia for the traumatic context can also be observed. Here, we show in mice that contextual amnesia is causally involved in PTSD-like memory formation, and that treating the amnesia by re-exposure to all trauma-related cues cures PTSD-like hypermnesia. These findings open a therapeutic perspective based on trauma contextualization and the underlying hippocampal mechanisms.


Assuntos
Amnésia/prevenção & controle , Amnésia/terapia , Condicionamento Psicológico/fisiologia , Memória/fisiologia , Transtornos de Estresse Pós-Traumáticos/prevenção & controle , Transtornos de Estresse Pós-Traumáticos/terapia , Amnésia/fisiopatologia , Animais , Aprendizagem da Esquiva/fisiologia , Sinais (Psicologia) , Emoções , Hipocampo/fisiopatologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Transtornos de Estresse Pós-Traumáticos/fisiopatologia
10.
PLoS One ; 15(8): e0237007, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790699

RESUMO

Although scientists agree that replications are critical to the debate on the validity of religious priming research, religious priming replications are scarce. This paper attempts to replicate and extend previously observed effects of religious priming on ethical behavior. We test the effect of religious instrumental music on individuals' ethical behavior with university participants (N = 408) in the Czech Republic, Japan, and the US. Participants were randomly assigned to listen to one of three musical tracks (religious, secular, or white noise) or to no music (control) for the duration of a decision-making game. Participants were asked to indicate which side of a vertically-bisected computer screen contained more dots and, in every trial, indicating that the right side of the screen had more dots earned participants the most money (irrespective of the number of dots). Therefore, participants were able to report dishonestly to earn more money. In agreement with previous research, we did not observe any main effects of condition. However, we were unable to replicate a moderating effect of self-reported religiosity on the effects of religious music on ethical behavior. Nevertheless, further analyses revealed moderating effects for ritual participation and declared religious affiliation congruent with the musical prime. That is, participants affiliated with a religious organization and taking part in rituals cheated significantly less than their peers when listening to religious music. We also observed significant differences in cheating behavior across samples. On average, US participants cheated the most and Czech participants cheated the least. We conclude that normative conduct is, in part, learned through active membership in religious communities and our findings provide further support for religious music as a subtle, moral cue.


Assuntos
Princípios Morais , Música , Religião , Adolescente , Adulto , Comparação Transcultural , Sinais (Psicologia) , República Tcheca , Tomada de Decisões/ética , Feminino , Humanos , Japão , Masculino , Estados Unidos , Jogos de Vídeo/ética , Adulto Jovem
11.
Am J Psychiatry ; 177(9): 818-826, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32731812

RESUMO

OBJECTIVE: Early adversity is correlated with increased risk for negative outcomes, including psychopathology and atypical neurodevelopment. The authors aimed to test the causal impact of an early parenting intervention (Attachment and Biobehavioral Catch-Up; ABC) on children's neural processing of parent cues and on psychosocial functioning in a longitudinal randomized clinical trial. METHODS: Participants (N=68, mean age, 10.0 years [SD=0.8 years]) were 46 high-risk children whose parents were randomly assigned to receive either the ABC intervention (N=22) or a control intervention (N=24) while the children were infants, in addition to a comparison sample of low-risk children (N=22). During functional MRI scanning, children viewed pictures of their own mothers and of a stranger. RESULTS: Children in the ABC condition showed greater maternal cue-related activation than children in the control condition in clusters of brain regions, including the precuneus, the cingulate gyrus, and the hippocampus, regions commonly associated with social cognition. Additionally, greater activity in these regions was associated with fewer total behavior problems. There was an indirect effect of early intervention on middle childhood psychosocial functioning mediated through increased activity in brain regions in response to maternal cues. CONCLUSIONS: These results suggest that early parenting intervention (in this case the ABC intervention) can enhance brain regions supporting children's social cognitive development. In addition, the findings highlight these brain effects as a possible neural pathway through which ABC may prevent future behavior problems among high-risk children, yielding psychosocial benefits that endure through at least middle childhood without the need to intervene with the child directly.


Assuntos
Encéfalo/diagnóstico por imagem , Educação não Profissionalizante/métodos , Mães/psicologia , Poder Familiar/psicologia , Habilidades Sociais , Encéfalo/fisiopatologia , Criança , Desenvolvimento Infantil/fisiologia , Sinais (Psicologia) , Feminino , Humanos , Lactente , Estudos Longitudinais , Imagem por Ressonância Magnética/métodos , Masculino , Transtornos do Neurodesenvolvimento/prevenção & controle , Apego ao Objeto , Avaliação de Processos e Resultados em Cuidados de Saúde , Relações Pais-Filho , Psicologia do Desenvolvimento/métodos , Medição de Risco
12.
PLoS One ; 15(8): e0232862, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32810143

RESUMO

Cognitive impairments can be a significant problem after a traumatic brain injury (TBI), which affects millions worldwide each year. There is a need for establish reproducible cognitive assays in rodents to better understand disease mechanisms and to develop therapeutic interventions towards treating TBI-induced impairments. Our goal was to validate and standardize the radial arm water maze (RAWM) test as an assay to screen for cognitive impairments caused by TBI. RAWM is a visuo-spatial learning test, originally designed for use with rats, and later adapted for mice. The present study investigates whether test procedures, such us the presence of extra-maze cues influences learning and memory performance. C57BL/6 mice were tested in an 8-arm RAWM using a four-day protocol. We demonstrated that two days of training, exposing the mice to extra-maze cues and a visible platform, influenced learning and memory performance. Mice that did not receive training performed poorer compared to mice trained. To further validate our RAWM protocol, we used scopolamine. We, also, demonstrated that a single mild closed head injury (CHI) caused deficits in this task at two weeks post-CHI. Our data supported the use of 7 trials per day and a spaced training protocol as key factor to unmask memory impairment following CHI. Here, we provide a detailed standard operating procedure for RAWM test, which can be applied to a variety of mouse models including neurodegenerative diseases and pathology, as well as when pharmacological approaches are used.


Assuntos
Concussão Encefálica/psicologia , Aprendizagem em Labirinto , Animais , Concussão Encefálica/complicações , Cognição , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/psicologia , Sinais (Psicologia) , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Testes de Memória e Aprendizagem , Camundongos , Camundongos Endogâmicos C57BL , Antagonistas Muscarínicos/farmacologia , Testes Neuropsicológicos , Escopolamina/farmacologia
13.
Proc Biol Sci ; 287(1933): 20201259, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32811312

RESUMO

Recent studies have emphasized the role of social learning and cultural transmission in promoting conformity and uniformity in animal groups, but little attention has been given to the role of negative frequency-dependent learning in impeding conformity and promoting diversity instead. Here, we show experimentally that under competitive conditions that are common in nature, social foragers (although capable of social learning) are likely to develop diversity in foraging specialization rather than uniformity. Naive house sparrows that were introduced into groups of foraging specialists did not conform to the behaviour of the specialists, but rather learned to use the alternative food-related cues, thus forming groups of complementary specialists. We further show that individuals in such groups may forage more effectively in diverse environments. Our results suggest that when the benefit from socially acquired skills diminishes through competition in a negative frequency-dependent manner, animal societies will become behaviourally diverse rather than uniform.


Assuntos
Comportamento Animal , Comportamento Social , Conformidade Social , Aprendizado Social , Pardais/fisiologia , Animais , Sinais (Psicologia) , Aprendizagem
14.
Proc Biol Sci ; 287(1933): 20201521, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32811316

RESUMO

Of all hypotheses advanced for why zebras have stripes, avoidance of biting fly attack receives by far the most support, yet the mechanisms by which stripes thwart landings are not yet understood. A logical and popular hypothesis is that stripes interfere with optic flow patterns needed by flying insects to execute controlled landings. This could occur through disrupting the radial symmetry of optic flow via the aperture effect (i.e. generation of false motion cues by straight edges), or through spatio-temporal aliasing (i.e. misregistration of repeated features) of evenly spaced stripes. By recording and reconstructing tabanid fly behaviour around horses wearing differently patterned rugs, we could tease out these hypotheses using realistic target stimuli. We found that flies avoided landing on, flew faster near, and did not approach as close to striped and checked rugs compared to grey. Our observations that flies avoided checked patterns in a similar way to stripes refutes the hypothesis that stripes disrupt optic flow via the aperture effect, which critically demands parallel striped patterns. Our data narrow the menu of fly-equid visual interactions that form the basis for the extraordinary colouration of zebras.


Assuntos
Dípteros , Pigmentação , Animais , Cor , Sinais (Psicologia) , Voo Animal , Mordeduras e Picadas de Insetos
15.
Proc Biol Sci ; 287(1933): 20201615, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32842923

RESUMO

An adequate supply of macro- and micronutrients determines health and reproductive success in most animals. Many bee species, for example, collect nectar and pollen to satisfy their demands for carbohydrates, protein and fat, respectively. Bees can assess the quality of pollen by feeding on it, but also pre-digestively by means of chemotactile assessment. Whether they additionally use larval nutritional experience, as has been shown for Drosophila melanogaster and Bombyx mori, is unknown. In this study, we tested whether pollen selection of bumblebee foragers is affected by nutritional experience (acquired before the onset of foraging) or solely by food quality. Bumblebee larvae were fed with one out of three different pollen blends. As adults, they were offered all three blends when they started foraging for the first time. We found all treatment groups to prefer one out of the three blends. This blend provided the highest nutritional quality and increased the bees' lifespan, as shown by feeding studies with microcolonies. Besides, bees also chose the pollen blend fed during their larval stage more often than expected, indicating a significant effect of pre-foraging experience on adult pollen foraging behaviour. The combination of both direct pollen quality assessment and pre-foraging experience (i.e. during the larval phase or as early imagines) seems to allow foraging bumblebees to efficiently select the most suitable pollen for their colony.


Assuntos
Abelhas/fisiologia , Sinais (Psicologia) , Comportamento Alimentar , Pólen , Animais , Drosophila melanogaster , Larva , Néctar de Plantas , Polinização , Reprodução
16.
Proc Biol Sci ; 287(1933): 20201212, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32842929

RESUMO

Predation produces intense selection and a diversity of defences. Reactive defences are triggered by predator cues, whereas proactive defences are always in effect. We assess whether prey rely on proactive defences when predator cues do not correlate well with predation risk. Many bats use echolocation to hunt insects, and many insects have evolved to hear bats. However, in species-rich environments like Neotropical forests, bats have extremely diverse foraging strategies, and the presence of echolocation corresponds only weakly to the presence of predators. We assess whether katydids that live in habitats with many non-dangerous bat species stop calling when exposed to echolocation. For 11 species of katydids, we quantified behavioural and neural responses to predator cues, and katydid signalling activity over 24 h periods. Despite having the sensory capacity to detect predators, many Neotropical forest katydids continued calling in the presence of predator cues, displaying proactive defences instead (short, infrequent calls totalling less than 2 cumulative seconds of sound per 24 h). Neotropical katydid signalling illustrates a fascinating case where trophic interactions are probably mediated by a third group: bats with alternative foraging strategies (e.g. frugivory). Although these co-occurring bats are not trophically connected, their mere presence disrupts the correlation between cue and predation risk.


Assuntos
Sinais (Psicologia) , Comportamento Predatório , Animais , Quirópteros/fisiologia , Vocalização Animal/fisiologia
17.
Sci Total Environ ; 737: 140257, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783852

RESUMO

Ecotoxicological effects of psychiatric drugs and drug metabolites released by the human population are of increasing environmental concern. In this study we evaluate behavioral responses to visual predator cues in wild caught three-spined stickleback (Gasterosteus aculeatus) after exposure to water-born citalopram, a widely prescribed selective serotonin reuptake inhibitor with antidepressant and anxiolytic effects. Fish were exposed to ecological relevant concentrations of citalopram (0.15 or 1.5 µg L-1) for 10 or 20 days. After drug exposure, individual fish were moved to a test arena where they were exposed to two naturalistic visual predator cues; a shadow from beneath, which simulated an approaching fish, and an overhead silhouette of a passing gull. Both visual cues resulted in decreased locomotor activity after post cue presentation. Notably, citalopram exposure resulted in a dose dependent suppression in response to the overhead stimulus. These results show that an ecologically relevant stimulus elicits a robust avoidance behavioral in wild caught fish after 25 min of acclimatization in the test arena. This suggests that the gull stimulus can be utilized as a behavioral endpoint in high flow through assays of ecotoxicological effects of psychiatric drugs and drug metabolites. Furthermore, the short acclimation time of wild caught fish in the test arena, opens for behavioral screening by fish living or kept in water bodies which are potentially impacted by psychiatric drugs.


Assuntos
Ansiolíticos , Smegmamorpha , Animais , Citalopram , Sinais (Psicologia) , Inibidores de Captação de Serotonina
18.
Nat Commun ; 11(1): 3764, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32724058

RESUMO

Context can influence reactions to environmental cues and this elemental process has implications for substance use disorder. Using an animal model, we show that an alcohol-associated context elevates entry into a fluid port triggered by a conditioned stimulus (CS) that predicted alcohol (CS-triggered alcohol-seeking). This effect persists across multiple sessions and, after it diminishes in extinction, the alcohol context retains the capacity to augment reinstatement. Systemically administered eticlopride and chemogenetic inhibition of ventral tegmental area (VTA) dopamine neurons reduce CS-triggered alcohol-seeking. Chemogenetically silencing VTA dopamine terminals in the nucleus accumbens (NAc) core reduces CS-triggered alcohol-seeking, irrespective of context, whereas silencing VTA dopamine terminals in the NAc shell selectively reduces the elevation of CS-triggered alcohol-seeking in an alcohol context. This dissociation reveals new roles for divergent mesolimbic dopamine circuits in the control of responding to a discrete cue for alcohol and in the amplification of this behaviour in an alcohol context.


Assuntos
Transtornos Relacionados ao Uso de Álcool/psicologia , Dopamina/metabolismo , Etanol/administração & dosagem , Extinção Psicológica/fisiologia , Área Tegmentar Ventral/fisiologia , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Condicionamento Clássico/efeitos dos fármacos , Condicionamento Clássico/fisiologia , Sinais (Psicologia) , Modelos Animais de Doenças , Antagonistas de Dopamina/administração & dosagem , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Comportamento de Procura de Droga/efeitos dos fármacos , Comportamento de Procura de Droga/fisiologia , Extinção Psicológica/efeitos dos fármacos , Feminino , Humanos , Masculino , Ratos , Salicilamidas/administração & dosagem , Técnicas Estereotáxicas , Área Tegmentar Ventral/citologia
19.
Proc Natl Acad Sci U S A ; 117(30): 18049-18058, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32661170

RESUMO

Cognitive flexibility depends on a fast neural learning mechanism for enhancing momentary relevant over irrelevant information. A possible neural mechanism realizing this enhancement uses fast spiking interneurons (FSIs) in the striatum to train striatal projection neurons to gate relevant and suppress distracting cortical inputs. We found support for such a mechanism in nonhuman primates during the flexible adjustment of visual attention in a reversal learning task. FSI activity was modulated by visual attention cues during feature-based learning. One FSI subpopulation showed stronger activation during learning, while another FSI subpopulation showed response suppression after learning, which could indicate a disinhibitory effect on the local circuit. Additionally, FSIs that showed response suppression to learned attention cues were activated by salient distractor events, suggesting they contribute to suppressing bottom-up distraction. These findings suggest that striatal fast spiking interneurons play an important role when cues are learned that redirect attention away from previously relevant to newly relevant visual information. This cue-specific activity was independent of motor-related activity and thus tracked specifically the learning of reward predictive visual features.


Assuntos
Atenção , Corpo Estriado/fisiologia , Sinais (Psicologia) , Interneurônios/fisiologia , Aprendizagem , Vias Neurais , Primatas , Potenciais de Ação , Animais , Cognição
20.
PLoS Comput Biol ; 16(7): e1008020, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32678847

RESUMO

Adaptation to statistics of sensory inputs is an essential ability of neural systems and extends their effective operational range. Having a broad operational range facilitates to react to sensory inputs of different granularities, thus is a crucial factor for survival. The computation of auditory cues for spatial localization of sound sources, particularly the interaural level difference (ILD), has long been considered as a static process. Novel findings suggest that this process of ipsi- and contra-lateral signal integration is highly adaptive and depends strongly on recent stimulus statistics. Here, adaptation aids the encoding of auditory perceptual space of various granularities. To investigate the mechanism of auditory adaptation in binaural signal integration in detail, we developed a neural model architecture for simulating functions of lateral superior olive (LSO) and medial nucleus of the trapezoid body (MNTB) composed of single compartment conductance-based neurons. Neurons in the MNTB serve as an intermediate relay population. Their signal is integrated by the LSO population on a circuit level to represent excitatory and inhibitory interactions of input signals. The circuit incorporates an adaptation mechanism operating at the synaptic level based on local inhibitory feedback signals. The model's predictive power is demonstrated in various simulations replicating physiological data. Incorporating the innovative adaptation mechanism facilitates a shift in neural responses towards the most effective stimulus range based on recent stimulus history. The model demonstrates that a single LSO neuron quickly adapts to these stimulus statistics and, thus, can encode an extended range of ILDs in the ipsilateral hemisphere. Most significantly, we provide a unique measurement of the adaptation efficacy of LSO neurons. Prerequisite of normal function is an accurate interaction of inhibitory and excitatory signals, a precise encoding of time and a well-tuned local feedback circuit. We suggest that the mechanisms of temporal competitive-cooperative interaction and the local feedback mechanism jointly sensitize the circuit to enable a response shift towards contra-lateral and ipsi-lateral stimuli, respectively.


Assuntos
Biologia Computacional , Neurônios/fisiologia , Núcleo Olivar/fisiologia , Sinapses/fisiologia , Corpo Trapezoide/fisiologia , Estimulação Acústica , Potenciais de Ação , Algoritmos , Animais , Vias Auditivas/fisiologia , Limiar Auditivo , Simulação por Computador , Sinais (Psicologia) , Gerbillinae , Humanos , Modelos Neurológicos , Distribuição Normal , Receptores de GABA/fisiologia , Reprodutibilidade dos Testes , Som , Localização de Som , Complexo Olivar Superior/fisiologia
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