RESUMEN
Introduction: Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, yet our comprehension predominantly relies on studies within the non-Hispanic White (NHW) population. Here we aimed to provide comprehensive insights into the proteomic landscape of AD across diverse racial and ethnic groups. Methods: Dorsolateral prefrontal cortex (DLPFC) and superior temporal gyrus (STG) brain tissues were donated from multiple centers (Mayo Clinic, Emory University, Rush University, Mt. Sinai School of Medicine) and were harmonized through neuropathological evaluation, specifically adhering to the Braak staging and CERAD criteria. Among 1105 DLPFC tissue samples (998 unique individuals), 333 were from African American donors, 223 from Latino Americans, 529 from NHW donors, and the rest were from a mixed or unknown racial background. Among 280 STG tissue samples (244 unique individuals), 86 were African American, 76 Latino American, 116 NHW and the rest were mixed or unknown ethnicity. All tissues were uniformly homogenized and analyzed by tandem mass tag mass spectrometry (TMT-MS). Results: As a Quality control (QC) measure, proteins with more than 50% missing values were removed and iterative principal component analysis was conducted to remove outliers within brain regions. After QC, 9,180 and 9,734 proteins remained in the DLPC and STG proteome, respectively, of which approximately 9,000 proteins were shared between regions. Protein levels of microtubule-associated protein tau (MAPT) and amyloid-precursor protein (APP) demonstrated AD-related elevations in DLPFC tissues with a strong association with CERAD and Braak across racial groups. APOE4 protein levels in brain were highly concordant with APOE genotype of the individuals. Discussion: This comprehensive region resolved large-scale proteomic dataset provides a resource for the understanding of ethnoracial-specific protein differences in AD brain.
RESUMEN
INTRODUCTION: Fundamental questions remain about the key mechanisms that initiate Alzheimer's disease (AD) and the factors that promote its progression. Here we report the successful generation of the first genetically engineered marmosets that carry knock-in (KI) point mutations in the presenilin 1 (PSEN1) gene that can be studied from birth throughout lifespan. METHODS: CRISPR/Cas9 was used to generate marmosets with C410Y or A426P point mutations in PSEN1. Founders and their germline offspring are comprehensively studied longitudinally using non-invasive measures including behavior, biomarkers, neuroimaging, and multiomics signatures. RESULTS: Prior to adulthood, increases in plasma amyloid beta were observed in PSEN1 mutation carriers relative to non-carriers. Analysis of brain revealed alterations in several enzyme-substrate interactions within the gamma secretase complex prior to adulthood. DISCUSSION: Marmosets carrying KI point mutations in PSEN1 provide the opportunity to study the earliest primate-specific mechanisms that contribute to the molecular and cellular root causes of AD onset and progression. HIGHLIGHTS: We report the successful generation of genetically engineered marmosets harboring knock-in point mutations in the PSEN1 gene. PSEN1 marmosets and their germline offspring recapitulate the early emergence of AD-related biomarkers. Studies as early in life as possible in PSEN1 marmosets will enable the identification of primate-specific mechanisms that drive disease progression.
Asunto(s)
Enfermedad de Alzheimer , Callithrix , Presenilina-1 , Animales , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/metabolismo , Animales Modificados Genéticamente , Encéfalo/patología , Encéfalo/metabolismo , Sistemas CRISPR-Cas , Modelos Animales de Enfermedad , Técnicas de Sustitución del Gen , Mutación/genética , Mutación Puntual/genética , Presenilina-1/genéticaRESUMEN
INTRODUCTION: Alzheimer's disease (AD) is the predominant dementia globally, with heterogeneous presentation and penetrance of clinical symptoms, variable presence of mixed pathologies, potential disease subtypes, and numerous associated endophenotypes. Beyond the difficulty of designing treatments that address the core pathological characteristics of the disease, therapeutic development is challenged by the uncertainty of which endophenotypic areas and specific targets implicated by those endophenotypes to prioritize for further translational research. However, publicly funded consortia driving large-scale open science efforts have produced multiple omic analyses that address both disease risk relevance and biological process involvement of genes across the genome. METHODS: Here we report the development of an informatic pipeline that draws from genetic association studies, predicted variant impact, and linkage with dementia associated phenotypes to create a genetic risk score. This is paired with a multi-omic risk score utilizing extensive sets of both transcriptomic and proteomic studies to identify system-level changes in expression associated with AD. These two elements combined constitute our target risk score that ranks AD risk genome-wide. The ranked genes are organized into endophenotypic space through the development of 19 biological domains associated with AD in the described genetics and genomics studies and accompanying literature. The biological domains are constructed from exhaustive Gene Ontology (GO) term compilations, allowing automated assignment of genes into objectively defined disease-associated biology. This rank-and-organize approach, performed genome-wide, allows the characterization of aggregations of AD risk across biological domains. RESULTS: The top AD-risk-associated biological domains are Synapse, Immune Response, Lipid Metabolism, Mitochondrial Metabolism, Structural Stabilization, and Proteostasis, with slightly lower levels of risk enrichment present within the other 13 biological domains. DISCUSSION: This provides an objective methodology to localize risk within specific biological endophenotypes and drill down into the most significantly associated sets of GO terms and annotated genes for potential therapeutic targets.
RESUMEN
Introduction: Our limited understanding of the mechanisms that trigger the emergence of Alzheimer's disease (AD) has contributed to the lack of interventions that stop, prevent, or fully treat this disease. We believe that the development of a non-human primate model of AD will be an essential step toward overcoming limitations of other model systems and is crucial for investigating primate-specific mechanisms underlying the cellular and molecular root causes of the pathogenesis and progression of AD. Methods: A new consortium has been established with funding support from the National Institute on Aging aimed at the generation, characterization, and validation of Marmosets As Research Models of AD (MARMO-AD). This consortium will study gene-edited marmoset models carrying genetic risk for AD and wild-type genetically diverse aging marmosets from birth throughout their lifespan, using non-invasive longitudinal assessments. These include characterizing the genetic, molecular, functional, behavioral, cognitive, and pathological features of aging and AD. Results: The consortium successfully generated viable founders carrying PSEN1 mutations in C410Y and A426P using CRISPR/Cas9 approaches, with germline transmission demonstrated in the C410Y line. Longitudinal characterization of these models, their germline offspring, and normal aging outbred marmosets is ongoing. All data and resources from this consortium will be shared with the greater AD research community. Discussion: By establishing marmoset models of AD, we will be able to investigate primate-specific cellular and molecular root causes that underlie the pathogenesis and progression of AD, overcome limitations of other model organisms, and support future translational studies to accelerate the pace of bringing therapies to patients.
RESUMEN
This article explores some of the marketing strategies associated with the British tobacco industry's sponsorship of sport during the 1960s and 1970s. It focuses on the British cigarette and tobacco manufacturer John Player & Sons and the firm's pioneering initiative to sponsor one-day cricket, which began with the John Player League in 1969. The league was enormously popular and gained significant broadcast coverage, becoming an invaluable means of increasing public exposure for the company, in the context of the ban of cigarette advertising from British television. At a time when the link between smoking and disease was making headlines, John Player & Sons nimbly deflected attention away from the health issue, and instead consciously repositioned the tobacco company as a generous benefactor of the nation's sport and leisure. Less conspicuously, but even more powerfully, spokespeople for the tobacco industry actively mobilised influential opinion behind the scenes in political circles. We show particularly how Denis Howell, Minister for Sport from 1964 to 1969 and from 1974 to 1979, became a valuable ally, acting as a bulwark against more restrictive government interventions into the sponsorship of sports by the tobacco industry. This alliance exposes changing industry-government relations and presents new historical context to better understand the way British tobacco manufacturers proactively sought to elide restrictions on their advertising activities from the 1980s onwards.
RESUMEN
Alzheimer's disease (AD) drug discovery has focused on a set of highly studied therapeutic hypotheses, with limited success. The heterogeneous nature of AD processes suggests that a more diverse, systems-integrated strategy may identify new therapeutic hypotheses. Although many target hypotheses have arisen from systems-level modeling of human disease, in practice and for many reasons, it has proven challenging to translate them into drug discovery pipelines. First, many hypotheses implicate protein targets and/or biological mechanisms that are under-studied, meaning there is a paucity of evidence to inform experimental strategies as well as high-quality reagents to perform them. Second, systems-level targets are predicted to act in concert, requiring adaptations in how we characterize new drug targets. Here we posit that the development and open distribution of high-quality experimental reagents and informatic outputs-termed target enabling packages (TEPs)-will catalyze rapid evaluation of emerging systems-integrated targets in AD by enabling parallel, independent, and unencumbered research.
RESUMEN
We propose an unbiased methodology to rank compounds for advancement into comprehensive preclinical testing for Alzheimer's disease (AD). Translation of compounds to the clinic in AD has been hampered by poor predictive validity of models, compounds with limited pharmaceutical properties, and studies that lack rigor. To overcome this, MODEL-AD's Preclinical Testing Core developed a standardized pipeline for assessing efficacy in AD mouse models. We hypothesize that rank-ordering compounds based upon pharmacokinetic, efficacy, and toxicity properties in preclinical models will enhance successful translation to the clinic. Previously compound selection was based solely on physiochemical properties, with arbitrary cutoff limits, making ranking challenging. Since no gold standard exists for systematic prioritization, validating a selection criteria has remained elusive. The STOP-AD framework evaluates the drug-like properties to rank compounds for in vivo studies, and uses an unbiased approach that overcomes the validation limitation by performing Monte-Carlo simulations. HIGHLIGHTS: Promising preclinical studies for AD drugs have not translated to clinical success. Systematic assessment of AD drug candidates may increase clinical translatability. We describe a well-defined framework for compound selection with clear selection metrics.
Asunto(s)
Enfermedad de Alzheimer , Animales , Ratones , Enfermedad de Alzheimer/tratamiento farmacológico , Modelos Animales de Enfermedad , Preparaciones FarmacéuticasRESUMEN
BACKGROUND: The COVID-19 epidemic imposed significant stressors on individuals and changed how medical care is delivered. The affect that this stress has placed on the field of bariatric surgery and the associated outcomes is not well established. METHODS: A retrospective review of a prospectively collected database from a single academic institution was conducted. Weight loss and comorbidity outcomes were compared between a cohort of patients operated on during the pandemic and a matched group operated on prior to COVID-19. GAD-7 and PHQ-9 questionnaires were used to assess for anxiety and depression, respectively. RESULTS: A total of 329 and 155 patients were enrolled in the pre-pandemic and COVID-19 groups respectively. There were no significant differences in pre-operative BMI (p = 0.437) or comorbidities: Type II DM (p = 0.810), hypertension (p = 0.879), sleep apnea (p = 0.502), and hyperlipidemia (p = 0.227). Post-operatively, weight loss was comparable at all time points out to 1 year. Type II DM resolution rates were higher in the control cohort at 6 months (p = 0.007), but not at 12 months (p = 1.000). There was no statistically significant difference in resolution rates between the control group and the COVID-19 group for the other measured comorbidities. There was no difference in objective measures of anxiety and depression when comparing the two groups (both p > 0.05). CONCLUSIONS: The COVID-19 pandemic has fundamentally changed how society and medical systems function. Focusing on pre-operative dietary training and screening for inadequately managed psychological comorbidities yielded similar weight loss outcomes notwithstanding the significant societal and individual stressors with which patients were faced.
Asunto(s)
Cirugía Bariátrica , COVID-19 , Obesidad Mórbida , Humanos , Obesidad Mórbida/cirugía , Pandemias , COVID-19/epidemiología , Comorbilidad , Pérdida de Peso , Estudios RetrospectivosRESUMEN
Two patients presented to outside providers with joint pain. Both had isolated lytic metaphyseal lesions on plain radiographs that were not noted or acted upon. Subsequent radiographs showed large expansile lytic lesions involving the metaphysis and epiphysis extending to the subchondral bone. Both patients were found to have pathology-confirmed giant cell tumors requiring curettage and cementation. Although commonly involving the epiphysis and subchondral bone, giant cell tumors of long bone can present as isolated metaphyseal lesions. Careful examination of radiographs and early detection may make these lesions easier to treat, reducing the risk of recurrence and damage to the articular surface.
RESUMEN
Hybrid incompatibilities occur when interactions between opposite ancestry alleles at different loci reduce the fitness of hybrids. Most work on incompatibilities has focused on those that are "intrinsic," meaning they affect viability and sterility in the laboratory. Theory predicts that ecological selection can also underlie hybrid incompatibilities, but tests of this hypothesis using sequence data are scarce. In this article, we compiled genetic data for F2 hybrid crosses between divergent populations of threespine stickleback fish (Gasterosteus aculeatus L.) that were born and raised in either the field (seminatural experimental ponds) or the laboratory (aquaria). Because selection against incompatibilities results in elevated ancestry heterozygosity, we tested the prediction that ancestry heterozygosity will be higher in pond-raised fish compared to those raised in aquaria. We found that ancestry heterozygosity was elevated by approximately 3% in crosses raised in ponds compared to those raised in aquaria. Additional analyses support a phenotypic basis for incompatibility and suggest that environment-specific single-locus heterozygote advantage is not the cause of selection on ancestry heterozygosity. Our study provides evidence that, in stickleback, a coarse-albeit indirect-signal of environment-dependent hybrid incompatibility is reliably detectable and suggests that extrinsic incompatibilities can evolve before intrinsic incompatibilities.
Asunto(s)
Ecosistema , Hibridación Genética/genética , Smegmamorpha/genética , Animales , Femenino , Genotipo , Heterocigoto , Masculino , Selección GenéticaRESUMEN
BACKGROUND: Alzheimer's disease (AD) is an incurable neurodegenerative disease currently affecting 1.75% of the US population, with projected growth to 3.46% by 2050. Identifying common genetic variants driving differences in transcript expression that confer AD risk is necessary to elucidate AD mechanism and develop therapeutic interventions. We modify the FUSION transcriptome-wide association study (TWAS) pipeline to ingest gene expression values from multiple neocortical regions. METHODS: A combined dataset of 2003 genotypes clustered to 1000 Genomes individuals from Utah with Northern and Western European ancestry (CEU) was used to construct a training set of 790 genotypes paired to 888 RNASeq profiles from temporal cortex (TCX = 248), prefrontal cortex (FP = 50), inferior frontal gyrus (IFG = 41), superior temporal gyrus (STG = 34), parahippocampal cortex (PHG = 34), and dorsolateral prefrontal cortex (DLPFC = 461). Following within-tissue normalization and covariate adjustment, predictive weights to impute expression components based on a gene's surrounding cis-variants were trained. The FUSION pipeline was modified to support input of pre-scaled expression values and support cross validation with a repeated measure design arising from the presence of multiple transcriptome samples from the same individual across different tissues. RESULTS: Cis-variant architecture alone was informative to train weights and impute expression for 6780 (49.67%) autosomal genes, the majority of which significantly correlated with gene expression; FDR < 5%: N = 6775 (99.92%), Bonferroni: N = 6716 (99.06%). Validation of weights in 515 matched genotype to RNASeq profiles from the CommonMind Consortium (CMC) was (72.14%) in DLPFC profiles. Association of imputed expression components from all 2003 genotype profiles yielded 8 genes significantly associated with AD (FDR < 0.05): APOC1, EED, CD2AP, CEACAM19, CLPTM1, MTCH2, TREM2, and KNOP1. CONCLUSIONS: We provide evidence of cis-genetic variation conferring AD risk through 8 genes across six distinct genomic loci. Moreover, we provide expression weights for 6780 genes as a valuable resource to the community, which can be abstracted across the neocortex and a wide range of neuronal phenotypes.
Asunto(s)
Enfermedad de Alzheimer/genética , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Neocórtex/metabolismo , Sitios de Carácter Cuantitativo , Transcriptoma , Biología Computacional/métodos , Regulación de la Expresión Génica , Estudio de Asociación del Genoma Completo/métodos , Humanos , Especificidad de Órganos/genéticaRESUMEN
A Correction to this paper has been published: https://doi.org/10.1038/s41467-020-20261-6.
RESUMEN
The temporal molecular changes that lead to disease onset and progression in Alzheimer's disease (AD) are still unknown. Here we develop a temporal model for these unobserved molecular changes with a manifold learning method applied to RNA-Seq data collected from human postmortem brain samples collected within the ROS/MAP and Mayo Clinic RNA-Seq studies. We define an ordering across samples based on their similarity in gene expression and use this ordering to estimate the molecular disease stage-or disease pseudotime-for each sample. Disease pseudotime is strongly concordant with the burden of tau (Braak score, P = 1.0 × 10-5), Aß (CERAD score, P = 1.8 × 10-5), and cognitive diagnosis (P = 3.5 × 10-7) of late-onset (LO) AD. Early stage disease pseudotime samples are enriched for controls and show changes in basic cellular functions. Late stage disease pseudotime samples are enriched for late stage AD cases and show changes in neuroinflammation and amyloid pathologic processes. We also identify a set of late stage pseudotime samples that are controls and show changes in genes enriched for protein trafficking, splicing, regulation of apoptosis, and prevention of amyloid cleavage pathways. In summary, we present a method for ordering patients along a trajectory of LOAD disease progression from brain transcriptomic data.
Asunto(s)
Encéfalo/patología , Degeneración Nerviosa/patología , Algoritmos , Enfermedad de Alzheimer/patología , Progresión de la Enfermedad , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Humanos , Degeneración Nerviosa/genética , Corteza Prefrontal/patología , Factores de Tiempo , Aprendizaje Automático no SupervisadoRESUMEN
The availability of high-quality RNA-sequencing and genotyping data of post-mortem brain collections from consortia such as CommonMind Consortium (CMC) and the Accelerating Medicines Partnership for Alzheimer's Disease (AMP-AD) Consortium enable the generation of a large-scale brain cis-eQTL meta-analysis. Here we generate cerebral cortical eQTL from 1433 samples available from four cohorts (identifying >4.1 million significant eQTL for >18,000 genes), as well as cerebellar eQTL from 261 samples (identifying 874,836 significant eQTL for >10,000 genes). We find substantially improved power in the meta-analysis over individual cohort analyses, particularly in comparison to the Genotype-Tissue Expression (GTEx) Project eQTL. Additionally, we observed differences in eQTL patterns between cerebral and cerebellar brain regions. We provide these brain eQTL as a resource for use by the research community. As a proof of principle for their utility, we apply a colocalization analysis to identify genes underlying the GWAS association peaks for schizophrenia and identify a potentially novel gene colocalization with lncRNA RP11-677M14.2 (posterior probability of colocalization 0.975).
Asunto(s)
Corteza Cerebelosa/metabolismo , Corteza Cerebral/metabolismo , Perfilación de la Expresión Génica , Sitios de Carácter Cuantitativo , Conjuntos de Datos como Asunto , Estudio de Asociación del Genoma Completo , Humanos , Metaanálisis como Asunto , ARN Largo no Codificante/genética , Esquizofrenia/genéticaRESUMEN
The AD Knowledge Portal (adknowledgeportal.org) is a public data repository that shares data and other resources generated by multiple collaborative research programs focused on aging, dementia, and Alzheimer's disease (AD). In this article, we highlight how to use the Portal to discover and download genomic variant and transcriptomic data from the same individuals. First, we show how to use the web interface to browse and search for data of interest using relevant file annotations. We demonstrate how to learn more about the context surrounding the data, including diagnostic criteria and methodological details about sample preparation and data analysis. We present two primary ways to download data-using a web interface, and using a programmatic method that provides access using the command line. Finally, we show how to merge separate sources of metadata into a comprehensive file that contains factors and covariates necessary in downstream analyses. © 2020 The Authors. Basic Protocol 1: Find and download files associated with a selected study Basic Protocol 2: Download files in bulk using the command line client Basic Protocol 3: Working with file annotations and metadata.
Asunto(s)
Envejecimiento , Enfermedad de Alzheimer/terapia , Bases de Datos Genéticas/estadística & datos numéricos , Genómica/métodos , Almacenamiento y Recuperación de la Información/métodos , Programas Informáticos , Enfermedad de Alzheimer/diagnóstico , Genómica/estadística & datos numéricos , Humanos , InternetRESUMEN
This article explores the historic records of the Walgreens Boots Alliance (WBA) Archive, a repository of over 500,000 items chronicling the over 165-year history of Britain's most famous pharmaceutical retailer. It introduces some of the diverse materials present in the collection that would be of interest to social historians of medicine and pharmacy, particularly highlighting resources pertinent to understanding developments in: the formation of pharmaceutical identity; medical advertising; the internationalisation of pharmaceutical and medical retailing; product research and development; and employee welfare. In the light of the recent launch of the first phase of the Boots online catalogue, the article demonstrates ways in which these records could be utilised to better understand the wider social, cultural and political dynamics at play in the development of medicine, health care and pharmacy in Britain over the long twentieth century.
RESUMEN
BACKGROUND: Periarticular injections have become a valuable adjunct to multimodal pain control regimens after knee and hip arthroplasties. Injection techniques vary greatly among surgeons with little standardization of practice. METHODS: We performed an extensive literature search to determine where nociceptive pain fibers are located in the hip and the knee and also to explore the pharmacology of periarticular cocktail ingredients. RESULTS: Large concentrations of nociceptors are present throughout the various tissues of the knee joint with elevated concentrations in the infrapatellar fat pad, fibrous capsule, ligament insertions, periosteum, subchondral bone, and lateral retinaculum. Less empiric evidence is available on nociceptor locations in the hip joint, but they are known to be located diffusely throughout the hip capsule with elevated concentrations at the labral base and central ligamentum teres. Local anesthetics are the base ingredient in most injection cocktails and function by blocking voltage-gated sodium channels. Liposomal anesthetics may offer longer duration of action over traditional anesthetics. Nonsteroidal anti-inflammatory agents and corticosteroids block peripheral production of inflammatory mediators and may desensitize nociceptors. Opioid receptors are present in lower densities peripherally as compared with the central nervous system, but their inclusion in injections can lead to pain relief. Sympathetic drugs can provide adjunct effects to periarticular cocktails to increase duration of action and effectiveness of medications. CONCLUSION: Targeting specific sites of nociceptors may help to further decrease pain after knee and hip arthroplasties. Altering periarticular cocktail ingredients may aid in multimodal pain control with injections.
Asunto(s)
Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Rodilla/efectos adversos , Inyecciones Intraarticulares , Manejo del Dolor/métodos , Dolor Postoperatorio/prevención & control , Anestésicos Locales/uso terapéutico , Antiinflamatorios no Esteroideos/uso terapéutico , Articulación de la Cadera/anatomía & histología , Humanos , Articulación de la Rodilla/anatomía & histología , Dolor Postoperatorio/etiologíaRESUMEN
Dopamine regulates reproduction in part by modulating neuronal activity within the hypothalamic-pituitary-gonadal (HPG) axis. Previous studies suggested numerous mechanisms by which dopamine exerts inhibitory control over the HPG axis, ultimately changing the levels of sex steroids that regulate reproductive behaviors. However, it is not known whether these mechanisms are conserved across vertebrate species. In particular, it is unknown whether mechanisms underlying dopaminergic control of reproduction are shared between mammals and teleost fish. In mammals, dopamine directly inhibits gonadotropin-releasing hormone (GnRH1) hypothalamic neurons, the gatekeepers for activation of the HPG axis. Here, we demonstrate, for the first time in teleost fish, dopaminergic control of GnRH1 neurons via direct dopamine type-2-like receptor (D2R)-mediated inhibition within the hypothalamus. These results suggest that direct dopaminergic control of GnRH1 neurons via interactions in the hypothalamus is not exclusive to tetrapod reproductive control, but is likely conserved across vertebrate species.
Asunto(s)
Cíclidos/fisiología , Dopamina/farmacología , Hormona Liberadora de Gonadotropina/metabolismo , Neuronas/metabolismo , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Femenino , Masculino , Neuronas/efectos de los fármacos , Área Preóptica/efectos de los fármacos , Área Preóptica/enzimología , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Caracteres Sexuales , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Despite longstanding interest in the genetic mechanisms that underlie behavioral evolution, very few genes that underlie naturally occurring variation in behavior between individuals or species are known, particularly in vertebrates. Here, we build on our previous forward genetic mapping experiments and use transgenic approaches to identify Ectodysplasin as a gene that causes differences in schooling behavior between wild populations of threespine stickleback (Gasterosteus aculeatus) fish. This work provides rare insight into the proximate mechanisms that have shaped the evolution of vertebrate behavior.