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1.
Nat Commun ; 11(1): 5074, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033265

RESUMO

Touch and itch sensations are crucial for evoking defensive and emotional responses, and light tactile touch may induce unpleasant itch sensations (mechanical itch or alloknesis). The neural substrate for touch-to-itch conversion in the spinal cord remains elusive. We report that spinal interneurons expressing Tachykinin 2-Cre (Tac2Cre) receive direct Aß low threshold mechanoreceptor (LTMR) input and form monosynaptic connections with GRPR neurons. Ablation or inhibition markedly reduces mechanical but not acute chemical itch nor noxious touch information. Chemogenetic inhibition of Tac2Cre neurons also displays pronounced deficit in chronic dry skin itch, a type of chemical itch in mice. Consistently, ablation of gastrin-releasing peptide receptor (GRPR) neurons, which are essential for transmitting chemical itch, also abolishes mechanical itch. Together, these results suggest that innocuous touch and chemical itch information converge on GRPR neurons and thus map an exquisite spinal circuitry hard-wired for converting innocuous touch to irritating itch.


Assuntos
Rede Nervosa/fisiopatologia , Prurido/fisiopatologia , Tato/fisiologia , Animais , Comportamento Animal , Injeções Espinhais , Luz , Potenciais da Membrana , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Precursores de Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptores da Bombesina/metabolismo , Pele/patologia , Medula Espinal/fisiopatologia , Sinapses/metabolismo , Taquicininas/metabolismo
3.
Nat Commun ; 11(1): 4966, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009404

RESUMO

Temporal lobe epilepsy (TLE) is the most common type of drug-resistant epilepsy in adults, with an unknown etiology. A hallmark of TLE is the characteristic loss of layer 3 neurons in the medial entorhinal area (MEA) that underlies seizure development. One approach to intervention is preventing loss of these neurons through better understanding of underlying pathophysiological mechanisms. Here, we show that both neurons and glia together give rise to the pathology that is mitigated by the amino acid D-serine whose levels are potentially diminished under epileptic conditions. Focal administration of D-serine to the MEA attenuates neuronal loss in this region thereby preventing epileptogenesis in an animal model of TLE. Additionally, treatment with D-serine reduces astrocyte counts in the MEA, alters their reactive status, and attenuates proliferation and/or infiltration of microglia to the region thereby curtailing the deleterious consequences of neuroinflammation. Given the paucity of compounds that reduce hyperexcitability and neuron loss, have anti-inflammatory properties, and are well tolerated by the brain, D-serine, an endogenous amino acid, offers new hope as a therapeutic agent for refractory TLE.


Assuntos
Epilepsia do Lobo Temporal/tratamento farmacológico , Epilepsia do Lobo Temporal/patologia , Serina/uso terapêutico , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Comportamento Animal , Encéfalo/patologia , Córtex Entorrinal/efeitos dos fármacos , Córtex Entorrinal/patologia , Gliose/patologia , Inflamação/patologia , Microglia/efeitos dos fármacos , Microglia/patologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Ratos Sprague-Dawley , Serina/administração & dosagem , Serina/farmacologia
4.
Elife ; 92020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32869742

RESUMO

New evidence that neighboring communities of bonobos hunt different prey species, despite extensive overlaps in where they live and hunt, is difficult to explain without invoking cultural factors.


Assuntos
Pan paniscus , Comportamento Social , Animais , Comportamento Animal , Fenótipo
5.
Proc Biol Sci ; 287(1934): 20201525, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32873200

RESUMO

Honeybees forage on diverse flowers which vary in the amount and type of rewards they offer, and bees are challenged with maximizing the resources they gather for their colony. That bees are effective foragers is clear, but how bees solve this type of complex multi-choice task is unknown. Here, we set bees a five-comparison choice task in which five colours differed in their probability of offering reward and punishment. The colours were ranked such that high ranked colours were more likely to offer reward, and the ranking was unambiguous. Bees' choices in unrewarded tests matched their individual experiences of reward and punishment of each colour, indicating bees solved this test not by comparing or ranking colours but by basing their colour choices on their history of reinforcement for each colour. Computational modelling suggests a structure like the honeybee mushroom body with reinforcement-related plasticity at both input and output can be sufficient for this cognitive strategy. We discuss how probability matching enables effective choices to be made without a need to compare any stimuli directly, and the use and limitations of this simple cognitive strategy for foraging animals.


Assuntos
Abelhas/fisiologia , Animais , Comportamento Animal , Comportamento de Escolha , Cor , Percepção de Cores , Simulação por Computador , Flores
6.
Proc Biol Sci ; 287(1934): 20201095, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32873202

RESUMO

The ideal free distribution (IFD) has been used to predict the distribution of foraging animals in a wide variety of systems. However, its predictions do not always match observed distributions of foraging animals. Instead, we often observe that there are more consumers than predicted in low-quality patches and fewer consumers than predicted in high-quality patches (i.e. undermatching). We examine the possibility that animal personality is one explanation for this undermatching. We first conducted a literature search to determine how commonly studies document the personality distribution of populations. Second, we created a simple individual-based model to conceptually demonstrate why knowing the distribution of personalities is important for studies of populations of foragers in context of the IFD. Third, we present a specific example where we calculate the added time to reach the IFD for a population of mud crabs that has a considerable number of individuals with relatively inactive personalities. We suggest that animal personality, particularly the prevalence of inactive personality types, may inhibit the ability of a population to track changes in habitat quality, therefore leading to undermatching of the IFD. This may weaken the IFD as a predictive model moving forward.


Assuntos
Comportamento Animal , Braquiúros/fisiologia , Animais , Ecossistema , Comportamento Alimentar
7.
Nat Commun ; 11(1): 4571, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917871

RESUMO

Early therapeutic interventions are essential to prevent Alzheimer Disease (AD). The association of several inflammation-related genetic markers with AD and the early activation of pro-inflammatory pathways in AD suggest inflammation as a plausible therapeutic target. Inflammatory Caspase-1 has a significant impact on AD-like pathophysiology and Caspase-1 inhibitor, VX-765, reverses cognitive deficits in AD mouse models. Here, a one-month pre-symptomatic treatment of Swedish/Indiana mutant amyloid precursor protein (APPSw/Ind) J20 and wild-type mice with VX-765 delays both APPSw/Ind- and age-induced episodic and spatial memory deficits. VX-765 delays inflammation without considerably affecting soluble and aggregated amyloid beta peptide (Aß) levels. Episodic memory scores correlate negatively with microglial activation. These results suggest that Caspase-1-mediated inflammation occurs early in the disease and raise hope that VX-765, a previously Food and Drug Administration-approved drug for human CNS clinical trials, may be a useful drug to prevent the onset of cognitive deficits and brain inflammation in AD.


Assuntos
Envelhecimento/metabolismo , Doença de Alzheimer/metabolismo , Disfunção Cognitiva/metabolismo , Serpinas/metabolismo , Proteínas Virais/metabolismo , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Animais , Comportamento Animal , Disfunção Cognitiva/tratamento farmacológico , Citocinas/metabolismo , Dipeptídeos/sangue , Dipeptídeos/farmacologia , Modelos Animais de Doenças , Encefalite/metabolismo , Encefalite/patologia , Feminino , Humanos , Inflamação/metabolismo , Masculino , Transtornos da Memória/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Serpinas/sangue , Serpinas/farmacologia , Memória Espacial/fisiologia , Proteínas Virais/sangue , Proteínas Virais/farmacologia , para-Aminobenzoatos/sangue , para-Aminobenzoatos/farmacologia
8.
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
9.
Nat Commun ; 11(1): 4686, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943633

RESUMO

Electrophysiology provides a direct readout of neuronal activity at a temporal precision only limited by the sampling rate. However, interrogating deep brain structures, implanting multiple targets or aiming at unusual angles still poses significant challenges for operators, and errors are only discovered by post-hoc histological reconstruction. Here, we propose a method combining the high-resolution information about bone landmarks provided by micro-CT scanning with the soft tissue contrast of the MRI, which allowed us to precisely localize electrodes and optic fibers in mice in vivo. This enables arbitrating the success of implantation directly after surgery with a precision comparable to gold standard histology. Adjustment of the recording depth with micro-drives or early termination of unsuccessful experiments saves many working hours, and fast 3-dimensional feedback helps surgeons avoid systematic errors. Increased aiming precision enables more precise targeting of small or deep brain nuclei and multiple targeting of specific cortical or hippocampal layers.


Assuntos
Encéfalo/diagnóstico por imagem , Eletrodos Implantados , Processamento de Imagem Assistida por Computador/métodos , Fibras Ópticas , Microtomografia por Raio-X/métodos , Animais , Comportamento Animal , Encéfalo/patologia , Mapeamento Encefálico , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Hipocampo/cirurgia , Técnicas Histológicas/métodos , Imagem por Ressonância Magnética/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Silício , Técnicas Estereotáxicas
10.
Nat Commun ; 11(1): 4715, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948772

RESUMO

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


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Cognição/fisiologia , Imagem por Ressonância Magnética/métodos , Imagem por Ressonância Magnética/veterinária , Vigília , Animais , Artefatos , Comportamento Animal/fisiologia , Mapeamento Encefálico , Columbidae , Humanos , Inibição Psicológica , Aprendizagem , Movimento (Física) , Redes Neurais de Computação , Recompensa
11.
Nat Commun ; 11(1): 4484, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901027

RESUMO

Chronic stress is a key risk factor for mood disorders like depression, but the stress-induced changes in brain circuit function and gene expression underlying depression symptoms are not completely understood, hindering development of novel treatments. Because of its projections to brain regions regulating reward and anxiety, the ventral hippocampus is uniquely poised to translate the experience of stress into altered brain function and pathological mood, though the cellular and molecular mechanisms of this process are not fully understood. Here, we use a novel method of circuit-specific gene editing to show that the transcription factor ΔFosB drives projection-specific activity of ventral hippocampus glutamatergic neurons causing behaviorally diverse responses to stress. We establish molecular, cellular, and circuit-level mechanisms for depression- and anxiety-like behavior in response to stress and use circuit-specific gene expression profiling to uncover novel downstream targets as potential sites of therapeutic intervention in depression.


Assuntos
Aprendizagem da Esquiva/fisiologia , Hipocampo/fisiologia , Proteínas Proto-Oncogênicas c-fos/fisiologia , Animais , Ansiedade/metabolismo , Comportamento Animal/fisiologia , Técnicas de Inativação de Genes , Inativação Gênica , Hipocampo/anatomia & histologia , Hipocampo/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Proteínas Proto-Oncogênicas c-fos/deficiência , Proteínas Proto-Oncogênicas c-fos/genética , Comportamento Social , Estresse Psicológico
12.
Nat Commun ; 11(1): 4529, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913184

RESUMO

Although Huntington's disease (HD) is a well studied Mendelian genetic disorder, less is known about its associated epigenetic changes. Here, we characterize DNA methylation levels in six different tissues from 3 species: a mouse huntingtin (Htt) gene knock-in model, a transgenic HTT sheep model, and humans. Our epigenome-wide association study (EWAS) of human blood reveals that HD mutation status is significantly (p < 10-7) associated with 33 CpG sites, including the HTT gene (p = 6.5 × 10-26). These Htt/HTT associations were replicated in the Q175 Htt knock-in mouse model (p = 6.0 × 10-8) and in the transgenic sheep model (p = 2.4 × 10-88). We define a measure of HD motor score progression among manifest HD cases based on multiple clinical assessments. EWAS of motor progression in manifest HD cases exhibits significant (p < 10-7) associations with methylation levels at three loci: near PEX14 (p = 9.3 × 10-9), GRIK4 (p = 3.0 × 10-8), and COX4I2 (p = 6.5 × 10-8). We conclude that HD is accompanied by profound changes of DNA methylation levels in three mammalian species.


Assuntos
Metilação de DNA , Epigênese Genética , Proteína Huntingtina/genética , Doença de Huntington/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Animais Geneticamente Modificados , Comportamento Animal , Ilhas de CpG/genética , Estudos Transversais , Modelos Animais de Doenças , Progressão da Doença , Feminino , Seguimentos , Técnicas de Introdução de Genes , Loci Gênicos , Estudo de Associação Genômica Ampla , Carga Global da Doença , Humanos , Doença de Huntington/sangue , Doença de Huntington/diagnóstico , Doença de Huntington/epidemiologia , Estudos Longitudinais , Masculino , Camundongos , Pessoa de Meia-Idade , Mutação , Estudos Prospectivos , Proteínas Recombinantes/genética , Sistema de Registros/estatística & dados numéricos , Índice de Gravidade de Doença , Ovinos , Adulto Jovem
13.
PLoS Biol ; 18(9): e3000818, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32960897

RESUMO

Humans profoundly impact landscapes, ecosystems, and animal behavior. In many cases, animals living near humans become tolerant of them and reduce antipredator responses. Yet, we still lack an understanding of the underlying evolutionary dynamics behind these shifts in traits that affect animal survival. Here, we used a phylogenetic meta-analysis to determine how the mean and variability in antipredator responses change as a function of the number of generations spent in contact with humans under 3 different contexts: urbanization, captivity, and domestication. We found that any contact with humans leads to a rapid reduction in mean antipredator responses as expected. Notably, the variance among individuals over time observed a short-term increase followed by a gradual decrease, significant for domesticated animals. This implies that intense human contact immediately releases animals from predation pressure and then imposes strong anthropogenic selection on traits. In addition, our results reveal that the loss of antipredator traits due to urbanization is similar to that of domestication but occurs 3 times more slowly. Furthermore, the rapid disappearance of antipredator traits was associated with 2 main life-history traits: foraging guild and whether the species was solitary or gregarious (i.e., group-living). For domesticated animals, this decrease in antipredator behavior was stronger for herbivores than for omnivores or carnivores and for solitary than for gregarious species. By contrast, the decrease in antipredator traits was stronger for gregarious, urbanized species, although this result is based mostly on birds. Our study offers 2 major insights on evolution in the Anthropocene: (1) changes in traits occur rapidly even under unintentional human "interventions" (i.e., urbanization) and (2) there are similarities between the selection pressures exerted by domestication and by urbanization. In all, such changes could affect animal survival in a predator-rich world, but through understanding evolutionary dynamics, we can better predict when and how exposure to humans modify these fitness-related traits.


Assuntos
Comportamento Animal/fisiologia , Evolução Biológica , Carnívoros/fisiologia , Atividades Humanas , Comportamento Predatório/fisiologia , Animais , Carnívoros/classificação , Domesticação , Ecossistema , Atividades Humanas/tendências , Humanos , Traços de História de Vida , Fenótipo , Urbanização/tendências
14.
Ecotoxicol Environ Saf ; 205: 111348, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32979803

RESUMO

Transgenerational effects induced by environmental stressors are a threat to ecosystems and human health. However, there is still limited observation and understanding of the potential of chemicals to influence life outcomes over several generations. In the present study, we investigated the effects of two environmental contaminants, coumarin 47 and permethrin, on exposed zebrafish (F0) and their progeny (F1-F3). Coumarin 47 is commonly found in personal care products and dyes, whereas permethrin is used as a domestic and agricultural pyrethroid insecticide/insect repellent. Zebrafish (F0) were exposed during early development until 28 days post-fertilization and their progeny (F1-F3) were bred unexposed. On one hand, the effects induced by coumarin 47 suggest no multigenerational toxicity. On the other hand, we found that behavior of zebrafish larvae was significantly affected by exposure to permethrin in F1 to F3 generations with some differences depending on the concentration. This suggests persistent alteration of the neural or neuromuscular function. In addition, lipidomic analyses showed that permethrin treatment was partially correlated with lysophosphatidylcholine levels in zebrafish, an important lipid for neurodevelopment. Overall, these results stress out one of the most widely used pyrethroids can trigger long-term, multi- and possibly transgenerational changes in the nervous system of zebrafish. These neurobehavioral changes echo the effects observed under direct exposure to high concentrations of permethrin and therefore call for more research on mechanisms underlying effect inheritance.


Assuntos
Cumarínicos/toxicidade , Repelentes de Insetos/toxicidade , Permetrina/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Cumarínicos/metabolismo , Ecossistema , Fertilidade/efeitos dos fármacos , Larva/efeitos dos fármacos , Metabolismo dos Lipídeos , Peixe-Zebra/metabolismo , Peixe-Zebra/fisiologia
15.
PLoS Negl Trop Dis ; 14(9): e0008531, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32911504

RESUMO

Pathogens may manipulate their human and mosquito hosts to enhance disease transmission. Dengue, caused by four viral serotypes, is the fastest-growing transmissible disease globally resulting in 50-100 million infections annually. Transmission of the disease relies on the interaction between humans and the vector Aedes aegypti and is largely dependent on the odor-mediated host seeking of female mosquitoes. In this study, we use activity monitors to demonstrate that dengue virus-1 affects the locomotion and odor-mediated behavior of Ae. aegypti, reflecting the progression of infection within the mosquito. Mosquitoes 4-6 days post-infection increase locomotion, but do not alter their odor-driven host-seeking response. In contrast, females 14-16 days post-infection are less active, yet more sensitive to human odors as assessed by behavioral and electrophysiological assays. Such an increase in physiological and behavioral sensitivity is reflected by the antennal-specific increase in abundance of neural signaling transcripts in 14 days post-infection females, as determined by transcriptome analysis. This suggests that the sensitivity of the mosquito peripheral olfactory system is altered by the dengue virus by enhancing the overall neural responsiveness of the antenna, rather than the selective regulation of chemosensory-related genes. Our study reveals that dengue virus-1 enhances vector-related behaviors in the early stages post-infection that aid in avoiding predation and increasing spatial exploration. On the other hand, at the later stages of infection, the virus enhances the host-seeking capacity of the vector, thereby increasing the risk of virus transmission. A potential mechanism is discussed.


Assuntos
Aedes/virologia , Dengue , Comportamento de Busca por Hospedeiro , Aedes/genética , Aedes/metabolismo , Aedes/fisiologia , Animais , Antenas de Artrópodes/fisiologia , Comportamento Animal , Vírus da Dengue/fisiologia , Feminino , Perfilação da Expressão Gênica , Humanos , Locomoção , Mosquitos Vetores/fisiologia , Mosquitos Vetores/virologia
16.
Proc Biol Sci ; 287(1935): 20201720, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32993473

RESUMO

Although dominance hierarchies occur in most societies, our understanding of how these power structures influence individual investment in cooperative and competitive behaviours remains elusive. Both conflict and cooperation in animal societies are often environmentally regulated, yet how individuals alter their cooperative and competitive investments as environmental quality changes remain unclear. Using game theoretic modelling, we predict that individuals of all ranks will invest more in cooperation and less in social conflict in harsh environments than individuals of the same ranks in benign environments. Counterintuitively, low-ranking subordinates should increase their investment in cooperation proportionally more than high-ranking dominants, suggesting that subordinates contribute relatively more when facing environmental challenges. We then test and confirm these predictions experimentally using the Asian burying beetle Nicrophorus nepalensis. Ultimately, we demonstrate how social rank modulates the relationships between environmental quality and cooperative and competitive behaviours, a topic crucial for understanding the evolution of complex societies.


Assuntos
Comportamento Animal , Comportamento Cooperativo , Predomínio Social , Animais , Comportamento Competitivo
17.
PLoS Biol ; 18(9): e3000584, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32956387

RESUMO

The insular cortex (IC) participates in diverse complex brain functions, including social function, yet their cellular bases remain to be fully understood. Using microendoscopic calcium imaging of the agranular insular cortex (AI) in mice interacting with freely moving and restrained social targets, we identified 2 subsets of AI neurons-a larger fraction of "Social-ON" cells and a smaller fraction of "Social-OFF" cells-that change their activity in opposite directions during social exploration. Social-ON cells included those that represented social investigation independent of location and consisted of multiple subsets, each of which was preferentially active during exploration under a particular behavioral state or with a particular target of physical contact. These results uncover a previously unknown function of AI neurons that may act to monitor the ongoing status of social exploration while an animal interacts with unfamiliar conspecifics.


Assuntos
Comportamento Animal/fisiologia , Córtex Cerebral/fisiologia , Comportamento Social , Animais , Córtex Cerebral/citologia , Masculino , Camundongos
18.
Nat Commun ; 11(1): 4614, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929069

RESUMO

The suprachiasmatic nucleus (SCN) is a complex structure dependent upon multiple mechanisms to ensure rhythmic electrical activity that varies between day and night, to determine circadian adaptation and behaviours. SCN neurons are exposed to glutamate from multiple sources including from the retino-hypothalamic tract and from astrocytes. However, the mechanism preventing inappropriate post-synaptic glutamatergic effects is unexplored and unknown. Unexpectedly we discovered that TRESK, a calcium regulated two-pore potassium channel, plays a crucial role in this system. We propose that glutamate activates TRESK through NMDA and AMPA mediated calcium influx and calcineurin activation to then oppose further membrane depolarisation and rising intracellular calcium. Hence, in the absence of TRESK, glutamatergic activity is unregulated leading to membrane depolarisation, increased nocturnal SCN firing, inverted basal calcium levels and impaired sensitivity in light induced phase delays. Our data reveals TRESK plays an essential part in SCN regulatory mechanisms and light induced adaptive behaviours.


Assuntos
Adaptação Ocular , Escuridão , Canais de Potássio/metabolismo , Núcleo Supraquiasmático/fisiologia , Animais , Comportamento Animal , Cálcio/metabolismo , Ácido Glutâmico/metabolismo , Luz , Potenciais da Membrana/efeitos da radiação , Camundongos Endogâmicos C57BL , Canais de Potássio/deficiência , Transdução de Sinais/efeitos da radiação , Núcleo Supraquiasmático/efeitos da radiação
19.
Nat Commun ; 11(1): 4451, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32934202

RESUMO

Large brains and behavioural innovation are positively correlated, species-specific traits, associated with the behavioural flexibility animals need for adapting to seasonal and unpredictable habitats. Similar ecological challenges would have been important drivers throughout human evolution. However, studies examining the influence of environmental variability on within-species behavioural diversity are lacking despite the critical assumption that population diversification precedes genetic divergence and speciation. Here, using a dataset of 144 wild chimpanzee (Pan troglodytes) communities, we show that chimpanzees exhibit greater behavioural diversity in environments with more variability - in both recent and historical timescales. Notably, distance from Pleistocene forest refugia is associated with the presence of a larger number of behavioural traits, including both tool and non-tool use behaviours. Since more than half of the behaviours investigated are also likely to be cultural, we suggest that environmental variability was a critical evolutionary force promoting the behavioural, as well as cultural diversification of great apes.


Assuntos
Comportamento Animal , Pan troglodytes/psicologia , Animais , Ecossistema , Meio Ambiente , Feminino , Florestas , Masculino , Pan troglodytes/fisiologia , Comportamento de Utilização de Ferramentas
20.
Ecotoxicol Environ Saf ; 205: 111289, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32949839

RESUMO

The Deepwater Horizon oil spill released 3.19 million barrels of crude oil into the Gulf of Mexico, making it the largest oil spill in U.S. history. Weathering and the application of dispersants can alter the solubility of compounds within crude oil, thus modifying the acute toxicity of the crude oil to aquatic life. The primary aim of our study was to determine the lasting impact of early-life stage sheepshead minnow (Cyprinodon variegatus variegatus) exposure to weathered, unweathered and dispersed crude oil on prey capture, male aggression, novel object interaction and global DNA methylation. Embryos were exposed from 1 to 10 dpf to water accommodations of crude oil and were raised to adulthood in artificial seawater. Our results suggest exposure to crude oil did not result in lasting impairment of complex behavioral responses of male sheepshead minnow. Exposure to dispersed weathered oil, however, decreased border dwelling in response to a novel object (i.e. decreased anxiety). Principal component analysis revealed that exposure to weathered oil had no overarching effect, but that unweathered crude oil increased variability in exploratory behaviors but decreased variability in anxiety-associated behaviors. Further work is needed to understand the effects of oil exposure on fish behavior and the potential ecological impact of subtle behavioral changes in fishes.


Assuntos
Comportamento Animal/efeitos dos fármacos , Peixes Listrados/fisiologia , Larva/efeitos dos fármacos , Poluição por Petróleo/efeitos adversos , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Metilação de DNA/efeitos dos fármacos , Ecologia , Golfo do México , Peixes Listrados/genética , Larva/genética , Larva/fisiologia , Masculino , Água do Mar/química , Tempo (Meteorologia)
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