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1.
Zootaxa ; 5057(2): 151-180, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34811215

RESUMO

Chlorospingus flavopectus, a widely distributed member of the New World sparrows and finches (Passerellidae), is among the most variable and complex Neotropical bird species. With up to 28 subspecies that inhabit montane forest from Mexico south to Argentina, it presents a recurring leapfrog pattern, with many genetically differentiated lineages, but even more morphologically distinguishable taxa. Chlorospingus flavopectus phaeocephalus is distributed along the eastern Andean slope (from southern Colombia to northern Peru) and in localized patches along the central and southwestern slopes of the Ecuadorian Andes, in the forest remnants of Chimborazo, El Oro, and adjacent Loja provinces. This allopatric distribution was based on plumage similarities, but no genetic or vocal analysis has tested if these populations share a common ancestry. Here, we compared data for populations of C. f. phaeocephalus, C. semifuscus semifuscus from northwest Ecuador, and C. s. livingstoni from west Colombia, and analyzed them in the context of other Chlorospingus. Our phylogenetic analyses revealed that the putative west Ecuadorian populations of C. f. phaeocephalus are nested within C. semifuscus. They also present diagnostic characters when compared to other populations of C. semifuscus and C. f. phaeocephalus. Based on these results, we recognize the population from El Oro and adjacent Loja Provinces as a new subspecies of C. semifuscus, and the population from Chimborazo Province as a morphological variation of C. s. semifuscus.


Assuntos
Tentilhões , Pardais , Animais , Filogenia
2.
Elife ; 102021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34723794

RESUMO

Acoustic signals serve communication within and across species throughout the animal kingdom. Studying the genetics, evolution, and neurobiology of acoustic communication requires annotating acoustic signals: segmenting and identifying individual acoustic elements like syllables or sound pulses. To be useful, annotations need to be accurate, robust to noise, and fast.We here introduce DeepAudioSegmenter (DAS), a method that annotates acoustic signals across species based on a deep-learning derived hierarchical presentation of sound. We demonstrate the accuracy, robustness, and speed of DAS using acoustic signals with diverse characteristics from insects, birds, and mammals. DAS comes with a graphical user interface for annotating song, training the network, and for generating and proofreading annotations. The method can be trained to annotate signals from new species with little manual annotation and can be combined with unsupervised methods to discover novel signal types. DAS annotates song with high throughput and low latency for experimental interventions in realtime. Overall, DAS is a universal, versatile, and accessible tool for annotating acoustic communication signals.


Assuntos
Acústica , Comunicação Animal , Callithrix/fisiologia , Drosophila melanogaster/fisiologia , Etologia/métodos , Camundongos/fisiologia , Aves Canoras/fisiologia , Animais , Feminino , Tentilhões/fisiologia , Masculino , Redes Neurais de Computação
3.
Nat Commun ; 12(1): 5791, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34608134

RESUMO

The brain is a hugely diverse, heterogeneous structure. Whether or not heterogeneity at the neural level plays a functional role remains unclear, and has been relatively little explored in models which are often highly homogeneous. We compared the performance of spiking neural networks trained to carry out tasks of real-world difficulty, with varying degrees of heterogeneity, and found that heterogeneity substantially improved task performance. Learning with heterogeneity was more stable and robust, particularly for tasks with a rich temporal structure. In addition, the distribution of neuronal parameters in the trained networks is similar to those observed experimentally. We suggest that the heterogeneity observed in the brain may be more than just the byproduct of noisy processes, but rather may serve an active and important role in allowing animals to learn in changing environments.


Assuntos
Aprendizagem/fisiologia , Modelos Neurológicos , Rede Nervosa/fisiologia , Potenciais de Ação , Algoritmos , Animais , Encéfalo/fisiologia , Tentilhões , Neurônios/fisiologia , Fala/fisiologia , Análise e Desempenho de Tarefas , Fatores de Tempo
4.
Biol Lett ; 17(10): 20210362, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34699737

RESUMO

Individuals can express a range of disease phenotypes during infection, with important implications for epidemics. Tolerance, in particular, is a host response that minimizes the per-pathogen fitness costs of infection. Because tolerant hosts show milder clinical signs and higher survival, despite similar pathogen burdens, their potential for prolonged pathogen shedding may facilitate the spread of pathogens. To test this, we simulated outbreaks of mycoplasmal conjunctivitis in house finches, asking how the speed of transmission varied with tissue-specific and behavioural components of tolerance, milder conjunctivitis and anorexia for a given pathogen load, respectively. Because tissue-specific tolerance hinders pathogen deposition onto bird feeders, important transmission hubs, we predicted it would slow transmission. Because behavioural tolerance should increase interactions with bird feeders, we predicted it would speed transmission. Our findings supported these predictions, suggesting that variation in tolerance could help identify individuals most likely to transmit pathogens.


Assuntos
Doenças das Aves , Tentilhões , Infecções por Mycoplasma , Mycoplasma gallisepticum , Animais , Humanos , Infecções por Mycoplasma/veterinária
5.
FEMS Microbiol Ecol ; 97(11)2021 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-34626186

RESUMO

The commensal microbes inhabiting a host tissue can interact with invading pathogens and host physiology in ways that alter pathogen growth and disease manifestation. Prior work in house finches (Haemorhous mexicanus) found that resident ocular microbiomes were protective against conjunctival infection and disease caused by a relatively high dose of Mycoplasma gallisepticum. Here, we used wild-caught house finches to experimentally examine whether protective effects of the resident ocular microbiome vary with the dose of invading pathogen. We hypothesized that commensal protection would be strongest at low M. gallisepticum inoculation doses because the resident microbiome would be less disrupted by invading pathogen. Our five M. gallisepticum dose treatments were fully factorial with an antibiotic treatment to perturb resident microbes just prior to M. gallisepticum inoculation. Unexpectedly, we found no indication of protective effects of the resident microbiome at any pathogen inoculation dose, which was inconsistent with the prior work. The ocular bacterial communities at the beginning of our experiment differed significantly from those previously reported in local wild-caught house finches, likely causing this discrepancy. These variable results underscore that microbiome-based protection in natural systems can be context dependent, and natural variation in community composition may alter the function of resident microbiomes in free-living animals.


Assuntos
Doenças das Aves , Tentilhões , Microbiota , Infecções por Mycoplasma , Mycoplasma gallisepticum , Animais
6.
Behav Processes ; 192: 104491, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34478805

RESUMO

Social behavior is influenced by a host of factors, including the immune system; for example, song quality in male starlings predicts immunocompetence suggesting the development of the immune system is interconnected with aspects social development (Duffy and Ball, 2002). Treating birds with antibiotics during the perinatal period may alter this development, and thereby, social behaviors beyond song. We asked if antibiotic exposure during the perinatal period effected parenting and offspring social behavior (e.g. aggressive and affiliative behaviors) in zebra finches? We treated the drinking water of zebra finch parents and hatchlings from post-hatch day 5-14 with azithromycin or a vehicle control and monitored parenting/social behavior. After weaning, we transferred offspring from the breeding cage to group housing and monitored social behavior and integration into the colony by measuring aggressive and affiliative behaviors. For all treatments we saw a reduction in the number of songs performed by fathers, however, specifically for antibiotic treated offspring there was a reduction in affiliative behaviors relative to vehicle treated controls suggesting the immune system, perhaps via the guts microbiome, influences certain aspects of social behaviors in birds.


Assuntos
Tentilhões , Agressão , Animais , Antibacterianos/farmacologia , Masculino , Comportamento Social , Desmame
7.
Environ Pollut ; 290: 118026, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34479165

RESUMO

Exposure to crude oil during spill events causes a variety of pathologic effects in birds, including oxidative injury to erythrocytes, which is characterized in some species by the formation of Heinz bodies and subsequent anemia. However, not all species appear to develop Heinz bodies or anemia when exposed to oil, and there are limited controlled experiments that use both light and electron microscopy to evaluate structural changes within erythrocytes following oil exposure. In this study, we orally dosed zebra finches (Taeniopygia guttata) with 3.3 or 10 mL/kg of artificially weathered Deepwater Horizon crude oil or 10 mL/kg of peanut oil (vehicle control) daily for 15 days. We found that birds receiving the highest dosage experienced a significant increase in reticulocyte percentage, mean corpuscular hemoglobin concentration, and liver mass, as well as inflammation of the gastrointestinal tract and lymphocyte proliferation in the spleen. However, we found no evidence of Heinz body formation based on both light and transmission electron microscopy. Although there was a tendency for packed cell volume and hemoglobin to decrease in birds from the high dose group compared to control and low dose groups, the changes were not statistically significant. Our results indicate that additional experimental dosing studies are needed to understand factors (e.g., dose- and species-specific sensitivity) and confounding variables (e.g., dispersants) that contribute to the presence and severity of anemia resulting from oil exposure in birds.


Assuntos
Tentilhões , Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Animais , Ingestão de Alimentos , Poluentes Químicos da Água/toxicidade , Tempo (Meteorologia)
8.
Eur J Neurosci ; 54(9): 7072-7091, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34535925

RESUMO

Estrogens support major brain functions including cognition, reproduction, neuroprotection and sensory processing. Neuroestrogens are synthesized within some brain areas by the enzyme aromatase and can rapidly modulate local circuit functions, yet the cellular physiology and sensory-response profiles of aromatase neurons are essentially unknown. In songbirds, social and acoustic stimuli drive neuroestrogen elevations in the auditory forebrain caudomedial nidopallium (NCM). In both males and females, neuroestrogens rapidly enhance NCM auditory processing and auditory learning. Estrogen-producing neurons in NCM may therefore exhibit distinguishing profiles for sensory-activation and intrinsic electrophysiology. Here, we explored these questions using both immunocyctochemistry and electrophysiological recordings. Immunoreactivity for aromatase and the immediate early gene EGR1, a marker of activity and plasticity, were quantified in NCM of song-exposed animals versus silence-exposed controls. Using whole-cell patch clamp recordings from NCM slices, we also documented the intrinsic excitability profiles of aromatase-positive and aromatase-negative neurons. We observed that a subset of aromatase neurons were significantly activated during song playback, in both males and females, and in both hemispheres. A comparable population of non-aromatase-expressing neurons were also similarly driven by song stimulation. Membrane properties (i.e., resting membrane potential, rheobase, input resistance and multiple action potential parameters) were similarly indistinguishable between NCM aromatase and non-aromatase neurons. Together, these findings demonstrate that aromatase and non-aromatase neurons in NCM are indistinct in terms of their intrinsic electrophysiology and responses to song. Nevertheless, such similarities in response properties may belie more subtle differences in underlying conductances and/or computational roles that may be crucial to their function.


Assuntos
Córtex Auditivo , Tentilhões , Animais , Aromatase/genética , Aromatase/metabolismo , Córtex Auditivo/metabolismo , Estradiol , Feminino , Masculino , Neurônios/metabolismo , Prosencéfalo/metabolismo , Vocalização Animal
9.
Philos Trans R Soc Lond B Biol Sci ; 376(1836): 20200248, 2021 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-34482724

RESUMO

Songbird vocal learning has interesting behavioural and neural parallels with speech acquisition in human infants. Zebra finch males sing one unique song that they imitate from conspecific males, and both sexes learn to recognize their father's song. Although males copy the stereotyped syllable sequence of their father's song, the role of sequential information in recognition remains unclear. Here, we investigated father's song recognition after changing the serial order of syllables (switching the middle syllables, first and last syllables, or playing all syllables in inverse order). Behavioural approach and call responses of adult male and female zebra finches to their father's versus unfamiliar songs in playback tests demonstrated significant recognition of father's song with all syllable-order manipulations. We then measured behavioural responses to normal versus inversed-order father's song. In line with our first results, the subjects did not differentiate between the two. Interestingly, when males' strength of song learning was taken into account, we found a significant correlation between song imitation scores and the approach responses to the father's song. These findings suggest that syllable sequence is not essential for recognition of father's song in zebra finches, but that it does affect responsiveness of males in proportion to the strength of vocal learning. This article is part of the theme issue 'Vocal learning in animals and humans'.


Assuntos
Percepção Auditiva , Aprendizagem , Aves Canoras , Vocalização Animal , Animais , Feminino , Tentilhões , Masculino
10.
J Exp Biol ; 224(15)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34346502

RESUMO

Evidence from a number of species suggests that behaviours associated with social rank are positively correlated with metabolic rate. These studies, however, are based on metabolic measurements of isolated individuals, thereby ignoring potential effects of social interactions on metabolic rates. Here, we characterised three pertinent metabolic indices in the two predominant genetic colour morphs of the Gouldian finch (Erythrura gouldiae): diurnal resting metabolic rate (RMR), nocturnal basal metabolic rate (BMR) and exercise-induced maximal metabolic rate (MMR). Research reveals that red-headed morphs consistently dominate the less aggressive black-headed morphs and that the two morphs differ in other behavioural and physiological traits. We measured daytime RMR of intermorph naïve birds (first-year virgin males maintained in total isolation from opposite colour morphs) and their metabolic responses to viewing a socially unfamiliar bird of each colour. Subsequently, each bird was placed in a home cage with an opposite colour morph (intermorph exposed) and the series of measurements was repeated. Daytime RMR was indistinguishable between the two morphs, regardless of whether they were intermorph naïve or intermorph exposed. However, both red- and black-headed birds showed a greater short-term increase in metabolic rate when viewing an unfamiliar red-headed bird than when seeing a black-headed bird, but only when intermorph naïve. Measurements of BMR and exercise-induced MMR did not differ between the two morphs, and consequently, aerobic scope was indistinguishable between them. We propose that the behavioural differences between these two sympatric morphs are functionally complementary and represent evolutionary stable strategies permitting establishment of dominance status in the absence of metabolic costs.


Assuntos
Tentilhões , Pigmentação , Animais , Evolução Biológica , Cor , Tentilhões/genética , Humanos , Masculino , Fenótipo
11.
Science ; 373(6552): 343-348, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34437154

RESUMO

Spatial memory in vertebrates requires brain regions homologous to the mammalian hippocampus. Between vertebrate clades, however, these regions are anatomically distinct and appear to produce different spatial patterns of neural activity. We asked whether hippocampal activity is fundamentally different even between distant vertebrates that share a strong dependence on spatial memory. We studied tufted titmice, food-caching birds capable of remembering many concealed food locations. We found mammalian-like neural activity in the titmouse hippocampus, including sharp-wave ripples and anatomically organized place cells. In a non-food-caching bird species, spatial firing was less informative and was exhibited by fewer neurons. These findings suggest that hippocampal circuit mechanisms are similar between birds and mammals, but that the resulting patterns of activity may vary quantitatively with species-specific ethological needs.


Assuntos
Tentilhões/fisiologia , Hipocampo/fisiologia , Neurônios/fisiologia , Passeriformes/fisiologia , Células de Lugar/fisiologia , Memória Espacial , Potenciais de Ação , Animais , Fenômenos Eletrofisiológicos , Comportamento Alimentar , Feminino , Tentilhões/anatomia & histologia , Hipocampo/anatomia & histologia , Hipocampo/citologia , Masculino , Vias Neurais , Passeriformes/anatomia & histologia , Sono
12.
PLoS One ; 16(8): e0256599, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34464410

RESUMO

The endogenous opioid system is evolutionarily conserved across reptiles, birds and mammals and is known to modulate varied brain functions such as learning, memory, cognition and reward. To date, most of the behavioral and anatomical studies in songbirds have mainly focused on µ-opioid receptors (ORs). Expression patterns of δ-ORs in zebra finches, a well-studied species of songbird have not yet been reported, possibly due to the high sequence similarity amongst different opioid receptors. In the present study, a specific riboprobe against the δ-OR mRNA was used to perform fluorescence in situ hybridization (FISH) on sections from the male zebra finch brain. We found that δ-OR mRNA was expressed in different parts of the pallium, basal ganglia, cerebellum and the hippocampus. Amongst the song control and auditory nuclei, HVC (abbreviation used as a formal name) and NIf (nucleus interfacialis nidopallii) strongly express δ-OR mRNA and stand out from the surrounding nidopallium. Whereas the expression of δ-OR mRNA is moderate in LMAN (lateral magnocellular nucleus of the anterior nidopallium), it is low in the MSt (medial striatum), Area X, DLM (dorsolateral nucleus of the medial thalamus), RA (robust nucleus of the arcopallium) of the song control circuit and Field L, Ov (nucleus ovoidalis) and MLd (nucleus mesencephalicus lateralis, pars dorsalis) of the auditory pathway. Our results suggest that δ-ORs may be involved in modulating singing, song learning as well as spatial learning in zebra finches.


Assuntos
Encéfalo/metabolismo , Tentilhões/metabolismo , Receptores Opioides delta/metabolismo , Animais , Gânglios da Base/metabolismo , Cerebelo/metabolismo , Tentilhões/fisiologia , Hipocampo/metabolismo , Hibridização in Situ Fluorescente , Masculino , RNA Mensageiro/metabolismo , Receptores Opioides delta/fisiologia , Vocalização Animal/fisiologia
13.
Philos Trans R Soc Lond B Biol Sci ; 376(1835): 20200329, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34420388

RESUMO

The development of rhythmicity is foundational to communicative and social behaviours in humans and many other species, and mechanisms of synchrony could be conserved across species. The goal of the current paper is to explore evolutionary hypotheses linking vocal learning and beat synchronization through genomic approaches, testing the prediction that genetic underpinnings of birdsong also contribute to the aetiology of human interactions with musical beat structure. We combined state-of-the-art-genomic datasets that account for underlying polygenicity of these traits: birdsong genome-wide transcriptomics linked to singing in zebra finches, and a human genome-wide association study of beat synchronization. Results of competitive gene set analysis revealed that the genetic architecture of human beat synchronization is significantly enriched for birdsong genes expressed in songbird Area X (a key nucleus for vocal learning, and homologous to human basal ganglia). These findings complement ethological and neural evidence of the relationship between vocal learning and beat synchronization, supporting a framework of some degree of common genomic substrates underlying rhythm-related behaviours in two clades, humans and songbirds (the largest evolutionary radiation of vocal learners). Future cross-species approaches investigating the genetic underpinnings of beat synchronization in a broad evolutionary context are discussed. This article is part of the theme issue 'Synchrony and rhythm interaction: from the brain to behavioural ecology'.


Assuntos
Genoma , Aprendizagem , Música , Periodicidade , Aves Canoras/genética , Vocalização Animal , Animais , Tentilhões/genética , Genoma Humano , Humanos
14.
Sci Rep ; 11(1): 15832, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34349147

RESUMO

In invasive parasites, generalism is considered advantageous during the initial phase of introduction. Thereafter, fitness costs to parasites, such as host-specific mortality, can drive parasites towards specialism to avoid costly hosts. It is important to determine changes in host specificity of invasive populations to understand host-parasite dynamics and their effects on vulnerable host populations. We examined changes in mortality in the introduced avian vampire fly (Philornis downsi) (Diptera: Muscidae), a generalist myasis-causing ectoparasite, between 2004 and 2020 on Floreana Island (Galápagos). Mortality was measured as the proportion of immature larvae found upon host nest termination. Over the time period, the avian vampire fly was most abundant and had low mortality in nests of the critically endangered medium tree finch (Camarhynchus pauper) and had the highest mortality in nests of hybrid tree finches (Camarhynchus spp.). Low larval mortality was also found in small tree (Camarhynchus parvulus) and small ground finch (Geospiza fuliginosa) nests. Selection could favour avian vampire flies that select medium tree finch nests and/or avoid hybrid nests. Overall, the finding of differences in avian vampire fly survival across host species is parsimonious with the idea that the introduced fly may be evolving towards host specialisation.


Assuntos
Tentilhões/parasitologia , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Larva/crescimento & desenvolvimento , Muscidae/crescimento & desenvolvimento , Comportamento de Nidação , Animais , Muscidae/classificação
15.
Biol Lett ; 17(7): 20210327, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34256579

RESUMO

Material culture-that is, group-shared and socially learned object-related behaviour(s)-is a widespread and diverse phenomenon in humans. For decades, researchers have sought to confirm the existence of material culture in non-human animals; however, the main study systems of interest-namely, tool making and/or using non-human primates and corvids-cannot provide such confirmatory evidence: because long-standing ethical and logistical constraints handicap the collection of necessary experimental data. Synthesizing evidence across decades and disciplines, here, I present a novel framework for (mechanistic, developmental, behavioural, and comparative) study on animal material culture: avian nest construction.


Assuntos
Tentilhões , Comportamento de Nidação , Animais
16.
Sci Rep ; 11(1): 14746, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34285320

RESUMO

Zebra finch is a representative animal model for studying the molecular basis of human disorders of vocal development and communication. Accordingly, various functional studies of zebra finch have knocked down or introduced foreign genes in vivo; however, their germline transmission efficiency is remarkably low. The primordial germ cell (PGC)-mediated method is preferred for avian transgenic studies; however, use of this method is restricted in zebra finch due to the lack of an efficient gene transfer method for the germline. To target primary germ cells that are difficult to transfect and manipulate, an adenovirus-mediated gene transfer system with high efficiency in a wide range of cell types may be useful. Here, we isolated and characterized two types of primary germline-competent stem cells, PGCs and spermatogonial stem cells (SSCs), from embryonic and adult reproductive tissues of zebra finch and demonstrated that genes were most efficiently transferred into these cells using an adenovirus-mediated system. This system was successfully used to generate gene-edited PGCs in vitro. These results are expected to improve transgenic zebra finch production.


Assuntos
Adenoviridae/genética , Tentilhões/genética , Técnicas de Transferência de Genes , Vetores Genéticos/metabolismo , Animais , Animais Geneticamente Modificados/genética , Sistemas CRISPR-Cas/genética , Células Cultivadas , Feminino , Edição de Genes , Vetores Genéticos/genética , Células Germinativas/citologia , Células Germinativas/metabolismo , Masculino , Mutagênese , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
J Exp Biol ; 224(11)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34087935

RESUMO

Early life conditions can affect individuals for life, with harsh developmental conditions resulting in lower fitness, but the underlying mechanisms are not well understood. We hypothesized that immune function may be part of the underlying mechanism, when harsh developmental conditions result in less effective immune function. We tested this hypothesis by comparing innate immune function between zebra finches (Taeniopygia guttata) in adulthood (n=230; age 108-749 days) that were reared in either small or large broods. We used this experimental background to follow up our earlier finding that finches reared in large broods have a shorter lifespan. To render a broad overview of innate immune function, we used an array of six measures: bacterial killing capacity, hemagglutination, hemolysis, haptoglobin, nitric oxide and ovotransferrin. We found no convincing evidence for effects of natal brood size on any of the six measures of innate immune function. This raised the question whether the origin of variation in immune function was genetic, and we therefore estimated heritabilities using animal models. However, we found heritability estimates to be low (range 0.04-0.11) for all measured immune variables, suggesting variation in innate immune function can largely be attributed to environmental effects independent of early-life conditions as modified by natal brood size.


Assuntos
Tentilhões , Animais , Imunidade , Longevidade
18.
FASEB J ; 35(8): e21743, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34192361

RESUMO

The effects of stress exposure are likely to vary depending on life-stage and stressor. While it has been postulated that mild stress exposure may have beneficial effects, the duration of such effects and the underlying mechanisms are unclear. While the long-term effects of early-life stress are relatively well studied, we know much less about the effects of exposure in adulthood since the early- and adult-life environments are often similar. We previously reported that repeated experimental exposure to a relatively mild stressor in female zebra finches, first experienced in young adulthood, initially had no effect on mortality risk, reduced mortality in middle age, but the apparently beneficial effects disappeared in old age. We show here that this is underpinned by differences between the control and stress-exposed group in the pattern of telomere change, with stress-exposed birds showing reduced telomere loss in middle adulthood. We thereby provide novel experimental evidence that telomere dynamics play a key role linking stress resilience and aging.


Assuntos
Envelhecimento/genética , Envelhecimento/fisiologia , Tentilhões/genética , Tentilhões/fisiologia , Longevidade/genética , Longevidade/fisiologia , Homeostase do Telômero/genética , Homeostase do Telômero/fisiologia , Animais , Meio Ambiente , Feminino , Tentilhões/sangue , Fatores de Risco , Estresse Fisiológico/genética , Encurtamento do Telômero/genética , Encurtamento do Telômero/fisiologia
19.
BMC Oral Health ; 21(1): 302, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-34126984

RESUMO

BACKGROUND: The number and proportion of older people globally is growing faster than that of any other age group. At the same time the number of people retaining some of their own teeth is rising. There significant differences between those living in care and their community dwelling peers, with evidence showing those in care having fewer teeth and significantly higher levels of dental decay. There are numerous Cochrane reviews linking the use of fluoride to a reduction in dental decay, however, the majority of research on effectiveness has been conducted on children and consequently, children and adolescents tend to be the main recipients of fluoride interventions. There are to date no studies comparing the effectiveness of fluoride interventions in older people in care homes in the UK. However, prior to developing an appropriate protocol for full-scale trial comparing clinical effectiveness of fluoride interventions, there are a number of trial feasibility and statistical parameters that need to be clarified. METHODS: This trial is a single centre, multi-site randomised controlled assessor blind parallel group (three groups) trial, with the primary objective of establishing the feasibility, practicability and compliance of fluoride interventions to prevent dental decay in care homes. Secondary and tertiary objectives will aim to explore the acceptability of the interventions from resident, care home and dental services perspectives, and estimate the efficacy of the three different fluoride treatments. DISCUSSION: This feasibility trial will produce new knowledge and add value to a landscape that is under researched. Although the efficacy of fluoride interventions is proven, the feasibility of dental research and prevention in this vulnerable group and in the complex care home setting is novel. This work will not only add to our understanding of the interface of dental care and social care but will also contribute to our broader understanding on undertaking research in care home settings. Dental care for older people has been a longstanding issue, and the events of this past year has shone a light on the vulnerabilities of those residing in care homes and so this research is landing at a pivotal time. Trial registration EudraCT Registration 2017-002248-34. Registered 20th February 2018 https://www.clinicaltrialsregister.eu/ctr-search/search?query=2017-002248-34 .


Assuntos
Cárie Dentária , Tentilhões , Adolescente , Idoso , Animais , Criança , Cárie Dentária/prevenção & controle , Estudos de Viabilidade , Fluoretos/uso terapêutico , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
20.
Biol Lett ; 17(6): 20200767, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34157236

RESUMO

Social learning enables adaptive information acquisition provided that it is not random but selective. To understand species typical decision-making and to trace the evolutionary origins of social learning, the heuristics social learners use need to be identified. Here, we experimentally tested the nature of majority influence in the zebra finch. Subjects simultaneously observed two demonstrator groups differing in relative and absolute numbers (ratios 1 : 2/2 : 4/3 : 3/1 : 5) foraging from two novel food sources (black and white feeders). We find that demonstrator groups influenced observers' feeder choices (social learning), but that zebra finches did not copy the majority of individuals. Instead, observers were influenced by the foraging activity (pecks) of the demonstrators and in an anti-conformist fashion. These results indicate that zebra finches are not conformist, but are public information users.


Assuntos
Tentilhões , Aprendizado Social , Animais , Vocalização Animal
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