Comprehensive Assessment of Ischemic Stroke in Nonhuman Primates: Neuroimaging, Behavioral, and Serum Proteomic Analysis.

Ischemic strokes, prevalence and impactful, underscore the necessity of advanced research models closely resembling human physiology. Our study utilizes nonhuman primates (NHPs) to provide a detailed exploration of ischemic stroke, integrating neuroimaging data, behavioral outcomes, and serum proteomics to elucidate the complex interplay of factors involved in stroke pathophysiology. We observed a consistent pattern in infarct volume, peaking at 1-month postmiddle cerebral artery occlusion (MCAO) and then stabilized. This pattern was strongly correlated to notable changes in motor function and working memory performance. Using diffusion tensor imaging (DTI), we detected significant alterations in fractional anisotropy (FA) and mean diffusivity (MD) values, signaling microstructural changes in the brain. These alterations closely correlated with the neurological and cognitive deficits that we observed, highlighting the sensitivity of DTI metrics in stroke assessment. Behaviorally, the monkeys exhibited a reliance on their unaffected limb for compensatory movements, a common response to stroke impairment. This adaptation, along with consistent DTI findings, suggests a significant impact of stroke on motor function and spatial perception. Proteomic analysis through MS/MS functional enrichment identified two distinct groups of proteins with significant changes post-MCAO. Notably, MMP9, THBS1, MB, PFN1, and YWHAZ were identified as potential biomarkers and therapeutic targets for ischemic stroke. Our results underscore the complex nature of stroke and advocate for an integrated approach, combining neuroimaging, behavioral studies, and proteomics, for advancing our understanding and treatment of this condition.

Making sense of the costs of adversity throughout the lifespan on aging in humans and other animals.

Social adversity, particularly early in life, can cause lifelong damage to health; by now, numerous studies examine this relationship in non-human species, producing some important themes: A) Captive animals readily lack ethological validity, giving a special place to studies of natural populations; one must appreciate though, that animal studies typically benefit humans who themselves lack ecological validity, namely Westernized subjects. B) Animal studies of the links between social adversity and psychiatric maladies potentially produce anthropomorphism; however, long-term study of our closest relatives demonstrates how convincingly another primate can, for example, experience grief, rather than display "grief-like" behavior. C) Are long-term consequences of social adversity best viewed as maladaptive and pathological, or as adaptive preparation for similar adversity later in life?; the growing literature casts light on when adversity's consequences are the purview of medicine or natural history. D) Studies examining sustained adversity and aging can increasingly distinguish between aging versus diseases of aging or cohort effects, and between aging effects arising from direct physiological mechanisms or indirect behavioral ones.

Who you live with and what you duet for: a review of the function of primate duets in relation to their social organization.

Duets are one of the most fascinating displays in animal vocal communication, where two animals fine-tune the timing of their emissions to create a coordinated signal. Duetting behavior is widespread in the animal kingdom and is present in insects, birds, and mammals. Duets are essential to regulate activities within and between social units. Few studies assessed the functions of these vocal emissions experimentally, and for many species, there is still no consensus on what duets are used for. Here, we reviewed the literature on the function of duets in non-human primates, investigating a possible link between the social organization of the species and the function of its duetting behavior. In primates and birds, social conditions characterized by higher promiscuity might relate to the emergence of duetting behavior. We considered both quantitative and qualitative studies, which led us to hypothesize that the shift in the social organization from pair living to a mixed social organization might have led to the emergence of mate defense and mate guarding as critical functions of duetting behavior. Territory/resource ownership and defense functions are more critical in obligate pair-living species. Finally, we encourage future experimental research on this topic to allow the formulation of empirically testable predictions.

Social and economic interdependence as a basis for peaceful between-group relationships in nonhuman primates and humans.

Glowacki asserts that interdependent relationships beyond group boundaries are exceptionally rare among nonhuman mammals. However, rudimentary forms of interdependence can be seen in primate species that form multilevel societies, that is, core social units embedded within higher-level grouping categories. Studies of primate multilevel societies can enrich discussions about the evolutionary origins of peaceful between-group interactions in humans.

Primate social organization evolved from a flexible pair-living ancestor.

Explaining the evolution of primate social organization has been fundamental to understand human sociality and social evolution more broadly. It has often been suggested that the ancestor of all primates was solitary and that other forms of social organization evolved later, with transitions being driven by various life history traits and ecological factors. However, recent research showed that many understudied primate species previously assumed to be solitary actually live in pairs, and intraspecific variation in social organization is common. We built a detailed database from primary field studies quantifying the number of social units expressing different social organizations in each population. We used Bayesian phylogenetic models to infer the probability of each social organization, conditional on several socioecological and life history predictors. Here, we show that when intraspecific variation is accounted for, the ancestral social organization of primates was inferred to be variable, with the most common social organization being pair-living but with approximately 10 to 20% of social units of the ancestral population deviating from this pattern by being solitary living. Body size and activity patterns had large effects on transitions between types of social organizations. As in other mammalian clades, pair-living is closely linked to small body size and likely more common in ancestral species. Our results challenge the assumption that ancestral primates were solitary and that pair-living evolved afterward emphasizing the importance of focusing on field data and accounting for intraspecific variation, providing a flexible statistical framework for doing so.

The ability to inhibit impulses is related to social behavior in long-tailed macaques.

Performance in cognitive tasks has been linked to differences in species' social organization, yet to understand its function its relationship to within-species variation in behavior should also be explored. One important cognitive capacity, the ability to inhibit impulses, is typically better in egalitarian than despotic primate species and in primate species with strong fission-fusion dynamics. A different line of research indicates that a high ability to inhibit impulses is related to less aggressive behavior and more socio-positive behavior. However, within species the relationship between performance on cognitive inhibition tasks and variation in social behavior remains to be explored. Here we investigate how performance in a typical inhibition task in cognitive research is related to aggressive and socio-positive behavior in despotic long-tailed macaques. Twenty individuals living in two naturalistic mixed-sex groups were tested with the Plexiglass Hole Task. Aggressive behavior and three types of socio-positive behavior (neutral/friendly approaches, socio-positive signaling, and grooming others) among group members were measured. Individuals differed in their ability to inhibit impulses. Individuals that were not good at inhibiting impulses showed higher rates of aggressive behavior, but also more socio-positive signals, whereas inhibition was not related to neutral/friendly approaches and grooming. These results confirm the positive link between impulsiveness and aggression. In addition, the results indicate that some social-positive behavior may be enhanced when inhibition is limited. In this species, benefits potentially derived from aggression and socio-positive signals match a low ability to inhibit impulses, suggesting that a low ability to inhibit impulses may actually be advantageous. To understand differences between species in cognitive skills, understanding the benefits of variation in a cognitive capacity within a species is crucial.

Orçamento das atividades diárias de dois grupos de Callithrix jacchus em área urbana / Daily budget of two Callithrix jachus in an urban area

Foram monitorados dois grupos de saguis, Callithrix jacchus, entre 2001 e 2002, no campus da UFRPE, no Recife/PE, com o objetivo de identificar o orçamento diário das atividades comportamentais em ambiente urbano. Os grupos, denominados de Economins e Zoologins, foram amostrados sistematicamente pelo método de varredura com intervalos de cinco minutos. O grupo Economins, composto por três indivíduos, apresentou, percentualmente, as seguintes distribuições das categorias comportamentais: locomoção, 28.0 por cento; descanso, 24.1 por cento; forrageio, 13.3 por cento; alimentação, 3.9 por cento e outros, 30.8 por cento. O grupo Zoologins, composto por sete indivíduos, distribuiu sua atividade nas seguintes proporções: locomoção, 48.6 por cento; forrageio, 11.7 por cento; descanso, 7.0 por cento; alimentação, 2.0 por cento e outros 30.6 por cento. Algumas dessas diferenças podem ser explicadas pela alta quantidade de jovens presentes no Zoologins, e outras, por fatores ambientais e sociais. Confirmando o alto nível de sociabilidade da espécie, os dois grupos despenderam grandes proporções de seus respectivos tempos de atividade na categoria “outros”, que englobou comportamentos sociais.

Two groups of marmosets, Callithrix jacchus, were monitored, between 2001 and 2002 on the campus of UFRPE in Recife, in order to identify the daily budget of behavioral activities in an urban environment. The groups, called Economins and Zoologins were systematically sampled by the scanning method at intervals of five minutes. The group Economins, composed of three individuals, presented the following distributions of behavioral categories: locomotion, 28.0 percent resting, 24.1 percent; foraging, 13.3 percent, feeding, 3.9 percent, others 30.8 percent. The group Zoologins, composed of seven individuals, distributed its activity in the following proportions: locomotion, 48.6 percent; foraging, 11.7 percent; rest, 7.0 percent, food, 2.0 percent and others 30.6 percent. Some of these differences can be explained by the high number of young individuals in Zoologins, and others, for environmental and social factors. Confirming the high level of sociability of the species, the two groups spent large proportions of their time of activity in the 'other' category, which included social behaviors.

Biologia, manejo e medicina de primatas não humanos na pesquisa biomédica / Biology, medicine and management of non-human primates in biomedical research

Contém importantes textos para os pesquisadores envolvidos nos estudos deste tema e preenche um vácuo na literatura de nosso país. A publicação aborda conceitos modernos focados na criação em cativeiro, manejo, biologia, taxonomia, medicina e controle da qualidade dessa espécie animal, que tem contribuído largamente para o desenvolvimento de novas vacinas e pesquisas sobre o tratamento de doenças, auxiliando a aprimorar a qualidade da saúde de nossa população. No que diz respeito a ética, biossegurança, reprodução, genética, controle sanitário e legislação, a publicação também dispõe de teorias e práticas que contemplam a visão que os pesquisadores devem contemplar quamdo houver necessidade - ainda indispensável - do uso de animais em experimentação.

An empirical examination of the standard errors of maximum likelihood phylogenetic parameters under the molecular clock via bootstrapping

The molecular clock theory has greatly enlightened our understanding of macroevolutionary events. Maximum likelihood (ML) estimation of divergence times involves the adoption of fixed calibration points, and the confidence intervals associated with the estimates are generally very narrow. The credibility intervals are inferred assuming that the estimates are normally distributed, which may not be the case. Moreover, calculation of standard errors is usually carried out by the curvature method and is complicated by the difficulty in approximating second derivatives of the likelihood function. In this study, a standard primate phylogeny was used to examine the standard errors of ML estimates via the bootstrap method. Confidence intervals were also assessed from the posterior distribution of divergence times inferred via Bayesian Markov Chain Monte Carlo. For the primate topology under evaluation, no significant differences were found between the bootstrap and the curvature methods. Also, Bayesian confidence intervals were always wider than those obtained by ML.