Introduction: Advanced age is a primary risk factor for many chronic diseases and conditions; however, age-related immune dysregulation is not well understood. Animal models, particularly those that resemble human age-related physiological changes, are needed to better understand immunosenescence and to improve health outcomes. Here, we explore the utility of the olive baboon (Papio anubis) in studying age-related changes to the immune system and understanding mechanisms of immunosenescence.
View Article and Find Full Text PDFBroca's and Wernicke's areas are comprised of Brodmann areas 44, 45 and 22 in the human brain. Because of their roles in higher cognitive and linguistic function, there has been historical and contemporary interest in comparative studies on the morphology and cytoarchitectonic organization in Broca's and Wernicke's between primate species. One challenge to comparative morphological studies between human and nonhuman primates for Broca's and Wernicke's areas is the absence in homologous sulci used to define these regions.
View Article and Find Full Text PDFObjectives: Most human brains exhibit left hemisphere asymmetry for planum temporale (PT) surface area and gray matter volume, which is interpreted as cerebral lateralization for language. Once considered a uniquely human feature, PT asymmetries have now been documented in chimpanzees and olive baboons. The goal of the current study was to further investigate the evolution of PT asymmetries in nonhuman primates.
View Article and Find Full Text PDFIntroduction: Chemotherapy-related cognitive impairment (CRCI) remains poorly understood in terms of the mechanisms of cognitive decline. Neural hyperactivity has been reported on average in cancer survivors, but it is unclear which patients demonstrate this neurophenotype, limiting precision medicine in this population.
Methods: We evaluated a retrospective sample of 80 breast cancer survivors and 80 non-cancer controls, aged 35-73, for which we had previously identified and validated three data-driven, biological subgroups (biotypes) of CRCI.
Early adverse rearing conditions are known to have deleterious consequences on social behavior, cognition, and brain development of both human and nonhuman primates. We analyzed archival diffusion tensor imaging (DTI) data from mother- (MR) or nursery-reared (NR) chimpanzees and used support vector machine learning to determine whether we could retrospectively classify chimpanzees as MR or NR based on white matter fractional anisotropy (FA) decades after their rearing experiences. A significant proportion of chimpanzees were correctly classified as MR and NR based on white matter fractional anisotropy (76.
View Article and Find Full Text PDFUtilizing Automated Cognitive Testing Systems (ACTS) with group-housed nonhuman primates offers a number of advantages over manual testing and computerized testing of singly housed subjects. To date, ACTS usage has been limited to great apes or African monkeys. Here, we detail what we have learned while implementing ACTS with socially housed squirrel monkeys and rhesus macaques and provide information about the training process.
View Article and Find Full Text PDFChemotherapy-related cognitive impairment (CRCI) remains poorly understood in terms of the mechanisms of cognitive decline. Neural hyperactivity has been reported on average in cancer survivors, but it is unclear which patients demonstrate this neurophenotype, limiting precision medicine in this population. We evaluated a retrospective sample of 80 breast cancer survivors and 80 non-cancer controls, age 35-73, for which we had previously identified and validated three data-driven, biological subgroups (biotypes) of CRCI.
View Article and Find Full Text PDFAmong human and nonhuman primates, mutual eye gaze (MEG) and gaze following are believed to be important for social cognition and communicative signaling. The goals of this study were to examine how early rearing experiences contribute to individual variation in MEG and to examine the potential role of genetic factors underlying this variation. Subjects included 93 female and 23 male baboons (Papio anubis) ranging from 3 to 20 years of age.
View Article and Find Full Text PDFPsychiatric diagnosis is moving away from symptom-based classification and towards multi-dimensional, biologically-based characterization, or biotyping. We previously identified three biotypes of chemotherapy-related cognitive impairment based on functional brain connectivity. In this follow-up study of 80 chemotherapy-treated breast cancer survivors and 80 non-cancer controls, we evaluated additional factors to help explain biotype expression: neurofunctional stability, brain age, apolipoprotein (APOE) genotype, and psychoneurologic symptoms.
View Article and Find Full Text PDFHumans and chimpanzees are genetically similar and share a number of life history, behavioral, cognitive and neuroanatomical similarities. Notwithstanding, our understanding of age-related changes in cognitive and motor functions in chimpanzees remains largely unstudied despite recent evident demonstrating that chimpanzees exhibit many of the same neuropathological features of Alzheimer's disease observed in human postmortem brains. Here, we examined age-related differences in cognition and cortical thickness measured from magnetic resonance images in a sample of 215 chimpanzees ranging in age between 9 and 54 years.
View Article and Find Full Text PDFJoint attention (JA) is an important milestone in human infant development and is predictive of the onset of language later in life. Clinically, it has been reported that children at risk for or with a diagnosis of autism spectrum disorder (ASD) perform more poorly on measures of JA compared to neurotypical controls. JA is not unique to humans but has also been reported in great apes and to a lesser extent in more distantly related monkeys.
View Article and Find Full Text PDFDeclarative and imperative joint attention or joint engagement are important milestones in human infant development. These have been shown to be a significant predictor of later language development and are impaired in some individuals with, or at risk for, a diagnosis of autism spectrum disorder. Comparatively, while chimpanzees and other great apes have been reported to engage in imperative joint attention, evidence of declarative joint attention remains unclear based on existing studies.
View Article and Find Full Text PDFMany claim that social stimuli are rewarding to primates, but few, if any, studies have explicitly demonstrated their reward value. Here, we examined whether chimpanzees would produce overt responses for the opportunity to view conspecific social, compared to dynamic (video: Experiment 1) and static (picture: Experiment 2) control content. We also explored the relationships between variation in social reward and social behavior and cognition.
View Article and Find Full Text PDFDetermining the impact that the gene has on primate brain morphology can provide insight into the evolution of human cognition and language systems. Here, we tested whether polymorphisms in in chimpanzees account for gray matter volumetric variation in brain regions implicated in language and communication (particularly within the posterior superior temporal gyrus and inferior frontal gyrus). First, we identified the nature and frequencies of single nucleotide variants (SNVs) in in a sample of unrelated chimpanzees ( spp.
View Article and Find Full Text PDFSeveral primate species have been shown to exhibit age-related changes in cognition, brain, and behavior. However, severe neurodegenerative illnesses, such as Alzheimer's disease (AD), were once thought to be uniquely human. Recently, some chimpanzees naturally were documented to develop both neurofibrillary tangles and amyloid plaques, the main characteristics of AD pathology.
View Article and Find Full Text PDFAlthough the rattling of rattlesnakes ( and ) is widely accepted as being aposematic, the hypothesis that rattling deters approach from the snake's potentially dangerous adversaries has not been well tested. In a controlled study using rattling recorded from captive rattlesnakes () and a variety of comparison sounds or no-sound controls, domestic dogs () showed no hesitation to approach camouflaged speakers projecting the recorded rattles. The dogs were equally likely to approach speakers projecting rattling as they were to approach speakers playing control sounds, or speakers that were silent.
View Article and Find Full Text PDFBehavioral management programs aim to enhance the welfare of animal subjects that participate in research, thereby enhancing our ability to conduct ethical research projects. Socialization strategies, environmental enrichment techniques, opportunities for subjects to voluntarily participate in research procedures, and the provision of Functionally Appropriate Captive Environments are 4 major components of most behavioral management programs. The appropriate implementation of behavioral management programs should provide animals with opportunities to engage in species-typical activity patterns, contributing to valid and reliable animal models that require the smallest number of subjects to achieve meaningful results.
View Article and Find Full Text PDFEye gaze is widespread in nonhuman primate taxa and important for social cognition and communicative signaling. Bonobos and chimpanzees, two closely related primate species, differ in social organization, behavior, and cognition. Chimpanzees' eye gaze and gaze following has been studied extensively, whereas less is known about bonobos' eye gaze.
View Article and Find Full Text PDFMutual eye gaze plays an important role in primate social development and communication. In the current study, we examined the underlying experiential, genetic, and neuroanatomical basis of mutual eye gaze variation in adult captive chimpanzees. A multivariate analysis of variance revealed a significant rearing effect on bout length, with human-reared chimpanzees engaging in longer bouts of mutual gaze compared to mother-reared and wild-born individuals.
View Article and Find Full Text PDFNursery rearing has well-known consequences for primate species. Relative to some other primate species, research has indicated a reduced impact of nursery rearing on squirrel monkeys, particularly in terms of rates, severity, and persistence of abnormal behavior. We administered the Primate Neonatal Neurobehavioral Assessment to 29 dam-reared and 13 nursery-reared squirrel monkeys (Saimiri boliviensis boliviensis) at 2 and 6 weeks of age.
View Article and Find Full Text PDFThe vasopressin system has been implicated in the regulation of social behavior and cognition in humans, nonhuman primates and other social mammals. In chimpanzees, polymorphisms in the vasopressin V1a receptor gene (AVPR1A) have been associated with social dimensions of personality, as well as to responses to sociocommunicative cues and mirror self-recognition. Despite evidence of this association with social cognition and behavior, there is little research on the neuroanatomical correlates of AVPR1A variation.
View Article and Find Full Text PDFSquirrel monkeys are a long-standing biomedical model, with multiple species and subspecies housed in research facilities. Few studies have examined the developmental differences between these subspecies, which may affect research outcomes. The primate neonatal neurobehavioral assessment was completed at 2 weeks of age with 279 dam-reared squirrel monkeys (188 Saimiri boliviensis boliviensis, 45 S.
View Article and Find Full Text PDFUltrasonic vocalizations are widely used to examine affective states in rats, yet relatively few studies explore the acoustic features of vocalizations, especially in relation to drug exposure, and no studies have explored alterations in acoustic features over time. The goal of this study was to examine nicotine- and phencyclidine-induced alterations of bandwidth, duration, and frequency of 50 kHz vocalizations. The minimum and maximum frequency, bandwidth, and duration of calls were examined after 7 days of daily subcutaneous administration of phencyclidine (2.
View Article and Find Full Text PDF