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1.
Nat Commun ; 12(1): 4830, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376663

RESUMO

Choice-relevant brain regions in prefrontal cortex may progressively transform information about options into choices. Here, we examine responses of neurons in four regions of the medial prefrontal cortex as macaques performed two-option risky choices. All four regions encode economic variables in similar proportions and show similar putative signatures of key choice-related computations. We provide evidence to support a gradient of function that proceeds from areas 14 to 25 to 32 to 24. Specifically, we show that decodability of twelve distinct task variables increases along that path, consistent with the idea that regions that are higher in the anatomical hierarchy make choice-relevant variables more separable. We also show progressively longer intrinsic timescales in the same series. Together these results highlight the importance of the medial wall in choice, endorse a specific gradient-based organization, and argue against a modular functional neuroanatomy of choice.


Assuntos
Comportamento de Escolha/fisiologia , Macaca mulatta/fisiologia , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Potenciais de Ação/fisiologia , Algoritmos , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Mapeamento Encefálico , Imageamento por Ressonância Magnética/métodos , Modelos Neurológicos , Córtex Pré-Frontal/citologia
2.
Int J Mol Sci ; 22(15)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34360687

RESUMO

In the intestine, the innate immune system excludes harmful substances and invading microorganisms. Tuft cells are taste-like chemosensory cells found in the intestinal epithelium involved in the activation of group 2 innate lymphoid cells (ILC2). Although tuft cells in other tissues secrete the neurotransmitter acetylcholine (ACh), their function in the gut remains poorly understood. In this study, we investigated changes in the expression of genes and cell differentiation of the intestinal epithelium by stimulation with interleukin-4 (IL-4) or IL-13 in macaque intestinal organoids. Transcriptome analysis showed that tuft cell marker genes were highly expressed in the IL-4- and IL-13-treated groups compared with the control, and the gene expression of choline acetyltransferase (ChAT), a synthesis enzyme of ACh, was upregulated in IL-4- and IL-13-treated groups. ACh accumulation was observed in IL-4-induced organoids using high-performance liquid chromatography-mass spectrometry (HPLC/MS), and ACh strongly released granules from Paneth cells. This study is the first to demonstrate ACh upregulation by IL-4 induction in primates, suggesting that IL-4 plays a role in Paneth cell granule secretion via paracrine stimulation.


Assuntos
Acetilcolina/metabolismo , Diferenciação Celular , Interleucina-4/farmacologia , Intestinos/fisiologia , Organoides/metabolismo , Animais , Perfilação da Expressão Gênica , Interleucina-4/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Macaca fuscata/fisiologia , Macaca mulatta/metabolismo , Macaca mulatta/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Organoides/efeitos dos fármacos , Organoides/fisiologia
3.
Nat Commun ; 12(1): 4473, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294703

RESUMO

Feedback in the brain is thought to convey contextual information that underlies our flexibility to perform different tasks. Empirical and computational work on the visual system suggests this is achieved by targeting task-relevant neuronal subpopulations. We combine two tasks, each resulting in selective modulation by feedback, to test whether the feedback reflected the combination of both selectivities. We used visual feature-discrimination specified at one of two possible locations and uncoupled the decision formation from motor plans to report it, while recording in macaque mid-level visual areas. Here we show that although the behavior is spatially selective, using only task-relevant information, modulation by decision-related feedback is spatially unselective. Population responses reveal similar stimulus-choice alignments irrespective of stimulus relevance. The results suggest a common mechanism across tasks, independent of the spatial selectivity these tasks demand. This may reflect biological constraints and facilitate generalization across tasks. Our findings also support a previously hypothesized link between feature-based attention and decision-related activity.


Assuntos
Córtex Visual/fisiologia , Animais , Atenção/fisiologia , Tomada de Decisões/fisiologia , Discriminação Psicológica , Retroalimentação Sensorial , Macaca mulatta/fisiologia , Masculino , Modelos Neurológicos , Estimulação Luminosa , Comportamento Espacial/fisiologia , Processamento Espacial/fisiologia , Percepção Visual/fisiologia
4.
Commun Biol ; 4(1): 690, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099840

RESUMO

Brain signal recordings with epidural microarrays constitute a low-invasive approach for recording distributed neuronal signals. Epidural field potentials (EFPs) may serve as a safe and highly beneficial signal source for a variety of research questions arising from both basic and applied neuroscience. A wider use of these signals, however, is constrained by a lack of data on their specific information content. Here, we make use of the high spatial resolution and the columnar organization of macaque primary visual cortex (V1) to investigate whether and to what extent EFP signals preserve information about various visual stimulus features. Two monkeys were presented with different feature combinations of location, size, shape, and color, yielding a total of 375 stimulus conditions. Visual features were chosen to access different spatial levels of functional organization. We found that, besides being highly specific for locational information, EFPs were significantly modulated by small differences in size, shape, and color, allowing for high stimulus classification rates even at the single-trial level. The results support the notion that EFPs constitute a low-invasive, highly beneficial signal source for longer-term recordings for medical and basic research by showing that they convey detailed and reliable information about constituent features of activating stimuli.


Assuntos
Macaca mulatta/fisiologia , Córtex Visual , Animais , Mapeamento Encefálico , Potenciais Evocados Visuais , Masculino , Neurônios/fisiologia , Estimulação Luminosa
5.
Res Vet Sci ; 137: 127-137, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33965833

RESUMO

Rhesus macaque (Macaca mulatta) is widely applied in animal model construction of infertility, spermatogonia stem cell transplantation and male reproductive diseases. In this review, we describe the seasonal changes of the reproductive system in rhesus macaques, the regular pattern of spermatogenesis and spermatozoa maturation, and the differentiation of spermatogonia and spermatocytes. The duration of the M. mulatta spermatogenesis is approximately 10 days and seminiferous epithelium cycles mainly consist of 12 stages, which provide a suitable model for reproductive studies in non-human primates. Here, we summarize the features of gonadal development and sperm maturation in the rhesus monkeys, which provide important information in the studies of reproductive biology. Rhesus macaque is an excellent animal model in spermatogonia stem cell transplantation. We discuss the applications and progresses of assisted reproductive technologies in sperm liquefaction, semen cryopreservation and spermatogonia stem cell transplantation of rhesus macaques. Besides, we sort out recent proteomic analyses of male reproductive systems and semen samples in rhesus macaques. This review mainly focuses on male reproductive biology and application studies using M. mulatta, which would promote the development of new therapeutic interventions on assisted reproduction and reproductive disease studies in the future.


Assuntos
Genitália Masculina/fisiologia , Macaca mulatta/fisiologia , Espermatogênese , Espermatogônias/transplante , Transplante de Células-Tronco/veterinária , Animais , Criopreservação/veterinária , Masculino , Proteômica , Estações do Ano , Espermatozoides , Testículo/citologia
6.
Radiat Res ; 196(2): 204-212, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34043805

RESUMO

In the event of a radiological attack or accident, it is more likely that the absorbed radiation dose will be heterogeneous, rather than uniformly distributed throughout the body. This type of uneven dose distribution is known as partial-body irradiation (PBI). Partial exposure of the vital organs, specifically the highly radiosensitive intestines, may cause death, if the injury is significant and the post-exposure recovery is considerably compromised. Here we investigated the recovery rate and extent of recovery from PBI-induced intestinal damage in large animals. Rhesus macaques (Macaca mulatta) were randomly divided into four groups: sham-irradiated (0 Gy), 8 Gy PBI, 11 Gy PBI and 14 Gy PBI. A single dose of ionizing radiation was delivered in the abdominal region using a uniform bilateral anteroposterior and posteroanterior technique. Irradiated animals were scheduled for euthanasia on days 10, 28 or 60 postirradiation, and sham-irradiated animals on day 60. Intestinal structural injuries were assessed via crypt depth, villus height, and mucosal surface length in the four different intestinal regions (duodenum, proximal jejunum, distal jejunum and ileum) using H&E staining. Higher radiation doses corresponded with more injury at 10 days post-PBI and a faster recovery rate. However, at 60 days post-PBI, damage was still evident in all regions of the intestine. The proximal and distal ends (duodenum and ileum, respectively) sustained less damage and recovered more fully than the jejunum.


Assuntos
Duodeno/efeitos da radiação , Íleo/efeitos da radiação , Intestino Delgado/efeitos da radiação , Jejuno/efeitos da radiação , Animais , Duodeno/fisiopatologia , Humanos , Íleo/fisiopatologia , Mucosa Intestinal/fisiopatologia , Mucosa Intestinal/efeitos da radiação , Intestino Delgado/fisiopatologia , Intestinos/fisiopatologia , Intestinos/efeitos da radiação , Jejuno/fisiopatologia , Macaca mulatta/fisiologia , Primatas/fisiologia , Doses de Radiação , Radiação Ionizante , Irradiação Corporal Total
7.
Am J Phys Anthropol ; 176(1): 80-92, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33973647

RESUMO

OBJECTIVES: Here, we examine (1) if the sex-related differences in iron (Fe) and copper (Cu) isotope ratios, represented as δ56 Fe and δ65 Cu values, respectively observed in humans exist in bulk occipital bone and incisors of male and female non-human primates, and (2) if the variation of Fe and Cu isotope ratios, known to vary in human blood as a factor of age are similar in non-human primate bone. MATERIALS AND METHODS: Isotope ratios were measured from the skeletal elements of 20 rhesus macaques (Macaca mulatta) with known life history traits. The metals were purified by column chromatography and their isotope ratios measured by MC-ICP-MS. Data were analyzed using generalized additive models (GAM). RESULTS: When accounting for age and sex independently, we found a significant relationship between δ65 Cu values and occipital bone, but not in incisors. There were no significant relationships observed between δ56 Fe values, occipital bone, or incisors. Similarly, there were no significant relationships observed between δ56 Fe values, δ65 Cu values, and age. DISCUSSION: We suggest that Cu and Fe isotope ratios have the potential to be useful supplementary tools in future research in biological anthropology, but additional studies are needed to further verify the relationship between sex, age, δ65 Cu, and δ56 Fe values in primates.


Assuntos
Osso e Ossos/química , Cobre/análise , Isótopos de Ferro/análise , Macaca mulatta/fisiologia , Fatores Etários , Animais , Antropologia Física , Feminino , Masculino , Fatores Sexuais
8.
Elife ; 102021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33904411

RESUMO

The specific circuit mechanisms through which anesthetics induce unconsciousness have not been completely characterized. We recorded neural activity from the frontal, parietal, and temporal cortices and thalamus while maintaining unconsciousness in non-human primates (NHPs) with the anesthetic propofol. Unconsciousness was marked by slow frequency (~1 Hz) oscillations in local field potentials, entrainment of local spiking to Up states alternating with Down states of little or no spiking activity, and decreased coherence in frequencies above 4 Hz. Thalamic stimulation 'awakened' anesthetized NHPs and reversed the electrophysiologic features of unconsciousness. Unconsciousness is linked to cortical and thalamic slow frequency synchrony coupled with decreased spiking, and loss of higher-frequency dynamics. This may disrupt cortical communication/integration.


Assuntos
Anestésicos Intravenosos/farmacologia , Córtex Cerebral/efeitos dos fármacos , Hipnóticos e Sedativos/farmacologia , Macaca mulatta/fisiologia , Propofol/farmacologia , Tálamo/efeitos dos fármacos , Inconsciência/induzido quimicamente , Animais , Córtex Cerebral/fisiologia , Feminino , Masculino , Recuperação de Função Fisiológica/efeitos dos fármacos , Recuperação de Função Fisiológica/fisiologia , Tálamo/fisiologia
9.
Nat Commun ; 12(1): 1985, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33790275

RESUMO

Successful pursuit and evasion require rapid and precise coordination of navigation with adaptive motor control. We hypothesize that the dorsal anterior cingulate cortex (dACC), which communicates bidirectionally with both the hippocampal complex and premotor/motor areas, would serve a mapping role in this process. We recorded responses of dACC ensembles in two macaques performing a joystick-controlled continuous pursuit/evasion task. We find that dACC carries two sets of signals, (1) world-centric variables that together form a representation of the position and velocity of all relevant agents (self, prey, and predator) in the virtual world, and (2) avatar-centric variables, i.e. self-prey distance and angle. Both sets of variables are multiplexed within an overlapping set of neurons. Our results suggest that dACC may contribute to pursuit and evasion by computing and continuously updating a multicentric representation of the unfolding task state, and support the hypothesis that it plays a high-level abstract role in the control of behavior.


Assuntos
Cognição/fisiologia , Giro do Cíngulo/fisiologia , Macaca mulatta/fisiologia , Neurônios/fisiologia , Comportamento Predatório/fisiologia , Algoritmos , Animais , Fixação Ocular/fisiologia , Giro do Cíngulo/citologia , Hipocampo/fisiologia , Humanos , Masculino , Modelos Neurológicos , Córtex Motor/fisiologia , Desempenho Psicomotor/fisiologia , Recompensa
10.
Nat Commun ; 12(1): 2003, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33790282

RESUMO

Understanding how activity of visual neurons represents distinct components of attention and their dynamics that account for improved visual performance remains elusive because single-unit experiments have not isolated the intensive aspect of attention from attentional selectivity. We isolated attentional intensity and its single trial dynamics as determined by spatially non-selective attentional performance in an orientation discrimination task while recording from neurons in monkey visual area V4. We found that attentional intensity is a distinct cognitive signal that can be distinguished from spatial selectivity, reward expectations and motor actions. V4 spiking on single trials encodes a combination of sensory and cognitive signals on different time scales. Attentional intensity and the detection of behaviorally relevant sensory signals are well represented, but immediate reward expectation and behavioral choices are poorly represented in V4 spiking. These results provide a detailed representation of perceptual and cognitive signals in V4 that are crucial for attentional performance.


Assuntos
Algoritmos , Atenção/fisiologia , Macaca mulatta/fisiologia , Neurônios/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Animais , Fenômenos Eletrofisiológicos , Modelos Lineares , Masculino , Estimulação Luminosa/métodos , Pupila/fisiologia , Córtex Visual/citologia
11.
Nat Commun ; 12(1): 2000, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33790301

RESUMO

A crucial role of cortical networks is the conversion of sensory inputs into perception. In the cortical somatosensory network, neurons of the primary somatosensory cortex (S1) show invariant sensory responses, while frontal lobe neuronal activity correlates with the animal's perceptual behavior. Here, we report that in the secondary somatosensory cortex (S2), neurons with invariant sensory responses coexist with neurons whose responses correlate with perceptual behavior. Importantly, the vast majority of the neurons fall along a continuum of combined sensory and categorical dynamics. Furthermore, during a non-demanding control task, the sensory responses remain unaltered while the sensory information exhibits an increase. However, perceptual responses and the associated categorical information decrease, implicating a task context-dependent processing mechanism. Conclusively, S2 neurons exhibit intriguing dynamics that are intermediate between those of S1 and frontal lobe. Our results contribute relevant evidence about the role that S2 plays in the conversion of touch into perception.


Assuntos
Macaca mulatta/fisiologia , Neurônios/fisiologia , Células Receptoras Sensoriais/fisiologia , Córtex Somatossensorial/fisiologia , Percepção do Tato/fisiologia , Algoritmos , Animais , Lobo Frontal/citologia , Lobo Frontal/fisiologia , Modelos Neurológicos , Estimulação Física/métodos , Córtex Somatossensorial/citologia
12.
Nat Commun ; 12(1): 2315, 2021 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33875667

RESUMO

The clustering of neurons with similar response properties is a conspicuous feature of neocortex. In primary visual cortex (V1), maps of several properties like orientation preference are well described, but the functional architecture of color, central to visual perception in trichromatic primates, is not. Here we used two-photon calcium imaging in macaques to examine the fine structure of chromatic representation and found that neurons responsive to spatially uniform, chromatic stimuli form unambiguous clusters that coincide with blobs. Further, these responsive groups have marked substructure, segregating into smaller ensembles or micromaps with distinct chromatic signatures that appear columnar in upper layer 2/3. Spatially structured chromatic stimuli revealed maps built on the same micromap framework but with larger subdomains that go well beyond blobs. We conclude that V1 has an architecture for color representation that switches between blobs and a combined blob/interblob system based on the spatial content of the visual scene.


Assuntos
Percepção de Cores/fisiologia , Macaca mulatta/fisiologia , Neurônios/fisiologia , Córtex Visual/fisiologia , Vias Visuais/fisiologia , Animais , Cor , Feminino , Masculino , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Estimulação Luminosa/métodos , Córtex Visual/citologia
13.
Elife ; 102021 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-33759760

RESUMO

Human and nonhuman primates are good at identifying an object based on its motion, a task that is believed to be carried out by the ventral visual pathway. However, the neural mechanisms underlying such ability remains unclear. We trained macaque monkeys to do orientation discrimination for motion boundaries (MBs) and recorded neuronal response in area V2 with microelectrode arrays. We found 10.9% of V2 neurons exhibited robust orientation selectivity to MBs, and their responses correlated with monkeys' orientation-discrimination performances. Furthermore, the responses of V2 direction-selective neurons recorded at the same time showed correlated activity with MB neurons for particular MB stimuli, suggesting that these motion-sensitive neurons made specific functional contributions to MB discrimination tasks. Our findings support the view that V2 plays a critical role in MB analysis and may achieve this through a neural circuit within area V2.


Assuntos
Macaca mulatta/fisiologia , Percepção de Movimento/fisiologia , Neurônios/fisiologia , Córtex Visual/fisiologia , Vias Visuais/fisiologia , Animais , Masculino , Estimulação Luminosa
14.
BMC Biol ; 19(1): 49, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33726757

RESUMO

BACKGROUND: Attentional modulation in the visual cortex of primates is characterized by multiplicative changes of sensory responses with changes in the attentional state of the animal. The cholinergic system has been linked to such gain changes in V1. Here, we aim to determine if a similar link exists in macaque area MT. While rhesus monkeys performed a top-down spatial attention task, we locally injected a cholinergic agonist or antagonist and recorded single-cell activity. RESULTS: Although we confirmed cholinergic influences on sensory responses, there was no additional cholinergic effect on the attentional gain changes. Neither a muscarinic blockage nor a local increase in acetylcholine led to a significant change in the magnitude of spatial attention effects on firing rates. CONCLUSIONS: This suggests that the cellular mechanisms of attentional modulation in the extrastriate cortex cannot be directly inferred from those in the primary visual cortex.


Assuntos
Atenção/fisiologia , Agonistas Colinérgicos/farmacologia , Antagonistas Colinérgicos/farmacologia , Macaca mulatta/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Acetilcolina/farmacologia , Animais , Atenção/efeitos dos fármacos , Masculino , Mecamilamina/farmacologia , Escopolamina/farmacologia , Córtex Visual/efeitos dos fármacos , Percepção Visual/efeitos dos fármacos
15.
Nat Commun ; 12(1): 1103, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33597516

RESUMO

Neurons in some sensory areas reflect the content of working memory (WM) in their spiking activity. However, this spiking activity is seldom related to behavioral performance. We studied the responses of inferotemporal (IT) neurons, which exhibit object-selective activity, along with Frontal Eye Field (FEF) neurons, which exhibit spatially selective activity, during the delay period of an object WM task. Unlike the spiking activity and local field potentials (LFPs) within these areas, which were poor predictors of behavioral performance, the phase-locking of IT spikes and LFPs with the beta band of FEF LFPs robustly predicted successful WM maintenance. In addition, IT neurons exhibited greater object-selective persistent activity when their spikes were locked to the phase of FEF LFPs. These results reveal that the coordination between prefrontal and temporal cortex predicts the successful maintenance of visual information during WM.


Assuntos
Macaca mulatta/fisiologia , Memória de Curto Prazo/fisiologia , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Lobo Temporal/fisiologia , Potenciais de Ação/fisiologia , Algoritmos , Animais , Lobo Frontal/citologia , Lobo Frontal/fisiologia , Masculino , Modelos Neurológicos , Estimulação Luminosa , Córtex Pré-Frontal/citologia , Lobo Temporal/citologia
16.
Am J Primatol ; 83(2): e23231, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33400335

RESUMO

Processing advantages for particular colors (color-hierarchies) influence emotional regulation and cognitive functions in humans and manifest as an advantage of the red color, compared with the green color, in triggering response inhibition but not in response execution. It remains unknown how such color-hierarchies emerge in human cognition and whether they are the unique properties of human brain with advanced trichromatic vision. Dominant models propose that color-hierarchies are formed as experience-dependent learning that associates various colors with different human-made conventions and concepts (e.g., traffic lights). We hypothesized that if color-hierarchies modulate cognitive functions in trichromatic nonhuman primates, it would indicate a preserved neurobiological basis for such color-hierarchies. We trained six macaque monkeys to perform cognitive tasks that required behavioral control based on colored cues. Color-hierarchies significantly influenced monkeys' behavior and appeared as an advantage of the red color, compared to the green, in triggering response inhibition but not response execution. For all monkeys, the order of color-hierarchies, in response inhibition and also execution, was similar to that in humans. In addition, the cognitive effects of color-hierarchies were not limited to the trial in which the colored cues were encountered but also persisted in the following trials in which there was no colored cue on the visual scene. These findings suggest that color-hierarchies are not resulting from association of colors with human-made conventions and that simple processing advantage in retina or early visual pathways does not explain the cognitive effects of color-hierarchies. The discovery of color-hierarchies in cognitive repertoire of monkeys indicates that although the evolution of humans and monkeys diverged in about 25 million years ago, the color-hierarchies are evolutionary preserved, with the same order, in trichromatic primates and exert overarching effects on the executive control of behavior.


Assuntos
Visão de Cores , Cor , Macaca mulatta/fisiologia , Animais , Cognição , Feminino , Masculino
17.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33431695

RESUMO

The ability of cortical networks to integrate information from different sources is essential for cognitive processes. On one hand, sensory areas exhibit fast dynamics often phase-locked to stimulation; on the other hand, frontal lobe areas with slow response latencies to stimuli must integrate and maintain information for longer periods. Thus, cortical areas may require different timescales depending on their functional role. Studying the cortical somatosensory network while monkeys discriminated between two vibrotactile stimulus patterns, we found that a hierarchical order could be established across cortical areas based on their intrinsic timescales. Further, even though subareas (areas 3b, 1, and 2) of the primary somatosensory (S1) cortex exhibit analogous firing rate responses, a clear differentiation was observed in their timescales. Importantly, we observed that this inherent timescale hierarchy was invariant between task contexts (demanding vs. nondemanding). Even if task context severely affected neural coding in cortical areas downstream to S1, their timescales remained unaffected. Moreover, we found that these time constants were invariant across neurons with different latencies or coding. Although neurons had completely different dynamics, they all exhibited comparable timescales within each cortical area. Our results suggest that this measure is demonstrative of an inherent characteristic of each cortical area, is not a dynamical feature of individual neurons, and does not depend on task demands.


Assuntos
Cognição/fisiologia , Lobo Frontal/fisiologia , Neurônios/fisiologia , Córtex Somatossensorial/fisiologia , Animais , Humanos , Macaca mulatta/fisiologia , Estimulação Física , Tempo de Reação/fisiologia
18.
Nature ; 591(7849): 270-274, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33408410

RESUMO

Neural mechanisms that mediate the ability to make value-guided decisions have received substantial attention in humans and animals1-6. Experiments in animals typically involve long training periods. By contrast, choices in the real world often need to be made between new options spontaneously. It is therefore possible that the neural mechanisms targeted in animal studies differ from those required for new decisions, which are typical of human imaging studies. Here we show that the primate medial frontal cortex (MFC)7 is involved in making new inferential choices when the options have not been previously experienced. Macaques spontaneously inferred the values of new options via similarities with the component parts of previously encountered options. Functional magnetic resonance imaging (fMRI) suggested that this ability was mediated by the MFC, which is rarely investigated in monkeys3; MFC activity reflected different processes of comparison for unfamiliar and familiar options. Multidimensional representations of options in the MFC used a coding scheme resembling that of grid cells, which is well known in spatial navigation8,9, to integrate dimensions in this non-physical space10 during novel decision-making. By contrast, the orbitofrontal cortex held specific object-based value representations1,11. In addition, minimally invasive ultrasonic disruption12 of MFC, but not adjacent tissue, altered the estimation of novel choice values.


Assuntos
Comportamento de Escolha/fisiologia , Lobo Frontal/citologia , Lobo Frontal/fisiologia , Macaca mulatta/fisiologia , Neurônios/fisiologia , Adulto , Animais , Feminino , Células de Grade/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Córtex Pré-Frontal/citologia , Córtex Pré-Frontal/fisiologia , Navegação Espacial/fisiologia , Adulto Jovem
19.
J Med Primatol ; 50(2): 108-119, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33469948

RESUMO

BACKGROUND: Biomedical research has recently focused on developing new models of human disease by implementing genome-editing strategies in non-human primates (NHPs) to introduce relevant gene mutations. There is a need to establish objective semen evaluation methods to select sires for in vitro fertilization to perform germline editing in embryos. METHODS: Sperm motility kinematic parameters were evaluated using a computer-assisted semen analysis (CASA) instrument for rhesus macaques (Macaca mulatta), cynomolgus macaques (Macaca fascicularis), and common marmosets (Callithrix jacchus). RESULTS: Normative sperm kinematic parameters were established, revealing differences between marmosets and macaques. The impact of season on rhesus macaque sperm motility was modest, where changes in sperm motility related to season were dependent on the individual male. CONCLUSIONS: These data provide a baseline of normative kinematic parameters for three captive NHP species, in which implementation of CASA may serve as a tool to evaluate NHP semen quality.


Assuntos
Callithrix/fisiologia , Macaca fascicularis/fisiologia , Macaca mulatta/fisiologia , Análise do Sêmen/métodos , Motilidade Espermática , Espermatozoides/fisiologia , Animais , Fenômenos Biomecânicos , Masculino , Análise do Sêmen/instrumentação , Especificidade da Espécie
20.
Philos Trans R Soc Lond B Biol Sci ; 376(1819): 20190666, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33423624

RESUMO

Information about social partners is innately valuable to primates. Decisions about which sources of information to consume are highly naturalistic but also complex and place unusually strong demands on the brain's decision network. In particular, both the orbitofrontal cortex (OFC) and lateral prefrontal cortex (LPFC) play key roles in decision making and social behaviour, suggesting a likely role in social information-seeking as well. To test this idea, we developed a 'channel surfing' task in which monkeys were shown a series of 5 s video clips of conspecifics engaged in natural behaviours at a field site. Videos were annotated frame-by-frame using an ethogram of species-typical behaviours, an important source of social information. Between each clip, monkeys were presented with a choice between targets that determined which clip would be seen next. Monkeys' gaze during playback indicated differential engagement depending on what behaviours were presented. Neurons in both OFC and LPFC responded to choice targets and to video, and discriminated a subset of the behaviours in the ethogram during video viewing. These findings suggest that both OFC and LPFC are engaged in processing social information that is used to guide dynamic information-seeking decisions. This article is part of the theme issue 'Existence and prevalence of economic behaviours among non-human primates'.


Assuntos
Cognição , Macaca mulatta/fisiologia , Macaca mulatta/psicologia , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Recompensa , Comportamento Social , Animais , Masculino , Interação Social
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