15,351 results match your criteria brains rhesus

Studies of aging nonhuman primates illuminate the etiology of early-stage Alzheimer's-like neuropathology: An evolutionary perspective.

Am J Primatol 2021 May 7:e23254. Epub 2021 May 7.

Division of Neuropharmacology and Neurologic Diseases, Department of Pathology, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, USA.

Tau pathology in Alzheimer's disease (AD) preferentially afflicts the limbic and recently enlarged association cortices, causing a progression of mnemonic and cognitive deficits. Although genetic mouse models have helped reveal mechanisms underlying the rare, autosomal-dominant forms of AD, the etiology of the more common, sporadic form of AD remains unknown, and is challenging to study in mice due to their limited association cortex and lifespan. It is also difficult to study in human brains, as early-stage tau phosphorylation can degrade postmortem. Read More

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8-Substituted Triazolobenzodiazepines: and Pharmacology in Relation to Structural Docking at the α1 Subunit-Containing GABA Receptor.

Front Pharmacol 2021 20;12:625233. Epub 2021 Apr 20.

Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, United States.

In order to develop improved anxiolytic drugs, 8-substituted analogs of triazolam were synthesized in an effort to discover compounds with selectivity for α2/α3 subunit-containing GABA subtypes. Two compounds in this series, XLi-JY-DMH (6-(2-chlorophenyl)-8-ethynyl-1-methyl-4H-benzo [f][1,2,4]triazolo[4,3-a][1,4]diazepine) and SH-TRI-108 [(E)-8-ethynyl-1-methyl-6-(pyridin-2-yl)-4H-benzo [f][1,2,4]triazolo[4,3-a][1,4]diazepine], were evaluated for and properties associated with GABA subtype-selective ligands. In radioligand binding assays conducted in transfected HEK cells containing rat αXβ3γ2 subtypes (X = 1,2,3,5), no evidence of selectivity was obtained, although differences in potency relative to triazolam were observed overall (triazolam > XLi-JY-DMH > SH-TRI-108). Read More

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Auditory Decisions in the Supplementary Motor Area.

Prog Neurobiol 2021 May 3:102053. Epub 2021 May 3.

Department of Cognitive Neuroscience, Institute of Cell Physiology, Universidad Nacional Autónoma de México (UNAM), 04510, Mexico City, Mexico. Electronic address:

In human speech and communication across various species, recognizing and categorizing sounds is fundamental for the selection of appropriate behaviors. But how does the brain decide which action to perform based on sounds? We explored whether the premotor supplementary motor area (SMA), responsible for linking sensory information to motor programs, also accounts for auditory-driven decision making. To this end, we trained two rhesus monkeys to discriminate between numerous naturalistic sounds and words learned as target (T) or non-target (nT) categories. Read More

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Comparative analysis reveals distinctive epigenetic features of the human cerebellum.

PLoS Genet 2021 May 6;17(5):e1009506. Epub 2021 May 6.

Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia, United States of America.

Identifying the molecular underpinnings of the neural specializations that underlie human cognitive and behavioral traits has long been of considerable interest. Much research on human-specific changes in gene expression and epigenetic marks has focused on the prefrontal cortex, a brain structure distinguished by its role in executive functions. The cerebellum shows expansion in great apes and is gaining increasing attention for its role in motor skills and cognitive processing, including language. Read More

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Instantaneous movement-unrelated midbrain activity modifies ongoing eye movements.

Elife 2021 May 6;10. Epub 2021 May 6.

Werner Reichardt Centre for Integrative Neuroscience, Tübingen University, Tübingen, Germany.

At any moment in time, new information is sampled from the environment and interacts with ongoing brain state. Often, such interaction takes place within individual circuits that are capable of both mediating the internally ongoing plan as well as representing exogenous sensory events. Here we investigated how sensory-driven neural activity can be integrated, very often in the same neuron types, into ongoing saccade motor commands. Read More

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Rhesus monkeys as a translational model for late-onset Alzheimer's disease.

Aging Cell 2021 May 5:e13374. Epub 2021 May 5.

Division of Geriatrics, Department of Medicine, SMPH, Madison, WI, USA.

Age is a major risk factor for late-onset Alzheimer's disease (AD) but seldom features in laboratory models of the disease. Furthermore, heterogeneity in size and density of AD plaques observed in individuals are not recapitulated in transgenic mouse models, presenting an incomplete picture. We show that the amyloid plaque microenvironment is not equivalent between rodent and primate species, and that differences in the impact of AD pathology on local metabolism and inflammation might explain established differences in neurodegeneration and functional decline. Read More

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Neural presbycusis at ultra-high frequency in aged common marmosets and rhesus monkeys.

Aging (Albany NY) 2021 Apr 27;13. Epub 2021 Apr 27.

Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200011, P.R. China.

The aging of the population and environmental noise have contributed to high rates of presbycusis, also known as age-related hearing loss (ARHL). Because mice have a relatively short life span, murine models have not been suitable for determining the mechanism of presbycusis development and methods of diagnosis. Although the common marmoset, a non-human primate (NHP), is an ideal animal model for studying age-related diseases, its auditory spectrum has not been systematically studied. Read More

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Neural effects of propofol-induced unconsciousness and its reversal using thalamic stimulation.

Elife 2021 04 27;10. Epub 2021 Apr 27.

The Picower Institute for Learning and Memory and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States.

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. Read More

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HIV/SIV-infection induces opening of Pannexin-1 channels resulting in neuronal synaptic compromise: a novel therapeutic opportunity to prevent NeuroHIV.

J Neurochem 2021 Apr 26. Epub 2021 Apr 26.

Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, Texas, USA.

In healthy conditions, pannexin-1 (Panx-1) channels are in a close state, but in several pathological conditions, including HIV and NeuroHIV, the channel becomes open. However, the mechanism or contribution of Panx-1 channels to the Human Immunodeficiency Virus-1 (HIV) pathogenesis and NeuroHIV are unknown. To determine the contribution of Panx-1 channels to the pathogenesis of NeuroHIV, we used a well-established model of Simian Immunodeficiency Virus (SIV) infection in macaques (Macaca mulatta) in the presence of and absence of a Panx-1 blocker to later examine the synaptic/axonal compromise induced for the virus. Read More

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Early Rearing Conditions Affect Monoamine Metabolite Levels During Baseline and Periods of Social Separation Stress: A Non-human Primate Model ().

Front Hum Neurosci 2021 9;15:624676. Epub 2021 Apr 9.

Department of Psychology, Brigham Young University, Provo, UT, United States.

A variety of studies show that parental absence early in life leads to deleterious effects on the developing CNS. This is thought to be largely because evolutionary-dependent stimuli are necessary for the appropriate postnatal development of the young brain, an effect sometimes termed the "experience-expectant brain," with parents providing the necessary input for normative synaptic connections to develop and appropriate neuronal survival to occur. Principal among CNS systems affected by parental input are the monoamine systems. Read More

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The olfactory route is a potential way for SARS-CoV-2 to invade the central nervous system of rhesus monkeys.

Signal Transduct Target Ther 2021 04 24;6(1):169. Epub 2021 Apr 24.

National Kunming High-Level Biosafety Primate Research Center, Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, Yunnan, China.

Neurological manifestations are frequently reported in the COVID-19 patients. Neuromechanism of SARS-CoV-2 remains to be elucidated. In this study, we explored the mechanisms of SARS-CoV-2 neurotropism via our established non-human primate model of COVID-19. Read More

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Robust and distributed neural representation of action values.

Elife 2021 Apr 20;10. Epub 2021 Apr 20.

Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, Republic of Korea.

Studies in rats, monkeys, and humans have found action-value signals in multiple regions of the brain. These findings suggest that action-value signals encoded in these brain structures bias choices toward higher expected rewards. However, previous estimates of action-value signals might have been inflated by serial correlations in neural activity and also by activity related to other decision variables. Read More

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Cryopreservation of microglia enables single-cell RNA sequencing with minimal effects on disease-related gene expression patterns.

iScience 2021 Apr 25;24(4):102357. Epub 2021 Mar 25.

Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA.

Microglia play a key role in brain development, normal homeostasis, and neurodegenerative disorders. Single-cell technologies have led to important findings about microglia, with many animal model studies using single-cell RNA sequencing (scRNA-seq), whereas most human specimen studies using archived frozen brains for single-nucleus RNA sequencing (snRNA-seq). However, microglia compose a small proportion of the total brain tissue; snRNAseq depletes expression of microglia activation genes that characterize many diseases. Read More

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Intracerebroventricular Administration of AAV9-PHP.B SYN1-EmGFP Induces Widespread Transgene Expression in the Mouse and Monkey CNS.

Hum Gene Ther 2021 Apr 16. Epub 2021 Apr 16.

Emory University, 1371, Yerkes National Primate Research Center, Atlanta, Georgia, United States.

Viral vectors made from adeno-associated virus (AAV) have emerged as preferred tools in basic and translational neuroscience research to introduce or modify genetic material in cells of interest. The use of viral vectors is particularly attractive in non-transgenic species, such as non-human primates. Injections of AAV solutions into the cerebrospinal fluid (CSF) is an effective method to achieve a broad distribution of a transgene in the central nervous system. Read More

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[C]deschloroclozapine is an improved PET radioligand for quantifying a human muscarinic DREADD expressed in monkey brain.

J Cereb Blood Flow Metab 2021 Apr 14:271678X211007949. Epub 2021 Apr 14.

Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.

Previous work found that [C]deschloroclozapine ([C]DCZ) is superior to [C]clozapine ([C]CLZ) for imaging Designer Receptors Exclusively Activated by Designer Drugs (DREADDs). This study used PET to quantitatively and separately measure the signal from transfected receptors, endogenous receptors/targets, and non-displaceable binding in other brain regions to better understand this superiority. A genetically-modified muscarinic type-4 human receptor (hMDi) was injected into the right amygdala of a male rhesus macaque. Read More

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High-Frequency Oscillations in the Pallidum: A Pathophysiological Biomarker in Parkinson's Disease?

Mov Disord 2021 Apr 13. Epub 2021 Apr 13.

Department of Neurology, University of Minnesota, Minneapolis, Minnesota, USA.

Background: Abnormal oscillatory neural activity in the beta-frequency band (13-35 Hz) is thought to play a role in Parkinson's disease (PD); however, increasing evidence points to alterations in high-frequency ranges (>100 Hz) also having pathophysiological relevance.

Objectives: Studies have found that power in subthalamic nucleus (STN) high-frequency oscillations is increased with dopaminergic medication and during voluntary movements, implicating these brain rhythms in normal basal ganglia function. The objective of this study was to investigate whether similar signaling occurs in the internal globus pallidus (GPi), a nucleus increasingly used as a target for deep brain stimulation (DBS) for PD. Read More

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Structural differences in the hippocampus and amygdala of behaviorally inhibited macaque monkeys.

Hippocampus 2021 Apr 12. Epub 2021 Apr 12.

Laboratory of Brain and Cognitive Development, Institute of Psychology, University of Lausanne, Lausanne, Switzerland.

Behavioral inhibition is a temperamental disposition to react warily when confronted by unfamiliar people, objects, or events. Behaviorally inhibited children are at greater risk of developing anxiety disorders later in life. Previous studies reported that individuals with a history of childhood behavioral inhibition exhibit abnormal activity in the hippocampus and amygdala. Read More

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Animal Models of COVID-19. I. Comparative Virology and Disease Pathogenesis.

ILAR J 2021 Apr 9. Epub 2021 Apr 9.

Department of Comparative Medicine, John Hopkins School of Medicine, Baltimore, Maryland, USA.

The Coronavirus Disease 2019 (COVID-19) pandemic has fueled unprecedented development of animal models to understand disease pathogenesis, test therapeutics, and support vaccine development. Models previously developed to study severe acute respiratory syndrome coronavirus (SARS-CoV) have been rapidly deployed to study SARS-CoV-2. However, it has become clear that despite the common use of ACE2 as a receptor for both viruses, the host range of the 2 viruses does not entirely overlap. Read More

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Primate ventral striatum maintains neural representations of the value of previously rewarded objects for habitual seeking.

Nat Commun 2021 04 8;12(1):2100. Epub 2021 Apr 8.

School of Biological Sciences, Seoul National University (SNU), Seoul, 08826, Republic of Korea.

The ventral striatum (VS) is considered a key region that flexibly updates recent changes in reward values for habit learning. However, this update process may not serve to maintain learned habitual behaviors, which are insensitive to value changes. Here, using fMRI in humans and single-unit electrophysiology in macaque monkeys we report another role of the primate VS: that the value memory subserving habitual seeking is stably maintained in the VS. Read More

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Robust vestibular self-motion signals in macaque posterior cingulate region.

Elife 2021 04 8;10. Epub 2021 Apr 8.

CAS Center for Excellence in Brain Science and Intelligence Technology, Key Laboratory of Primate Neurobiology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China.

Self-motion signals, distributed ubiquitously across parietal-temporal lobes, propagate to limbic hippocampal system for vector-based navigation via hubs including posterior cingulate cortex (PCC) and retrosplenial cortex (RSC). Although numerous studies have indicated posterior cingulate areas are involved in spatial tasks, it is unclear how their neurons represent self-motion signals. Providing translation and rotation stimuli to macaques on a 6-degree-of-freedom motion platform, we discovered robust vestibular responses in PCC. Read More

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Stimulus-dependent relationships between behavioral choice and sensory neural responses.

Elife 2021 Apr 7;10. Epub 2021 Apr 7.

Brain & Cognitive Sciences, Center for Visual Science, University of Rochester, Rochester, United States.

Understanding perceptual decision-making requires linking sensory neural responses to behavioral choices. In two-choice tasks, activity-choice covariations are commonly quantified with a single measure of choice probability (CP), without characterizing their changes across stimulus levels. We provide theoretical conditions for stimulus dependencies of activity-choice covariations. Read More

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Likelihood approximation networks (LANs) for fast inference of simulation models in cognitive neuroscience.

Elife 2021 Apr 6;10. Epub 2021 Apr 6.

Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, United States.

In cognitive neuroscience, computational modeling can formally adjudicate between theories and affords quantitative fits to behavioral/brain data. Pragmatically, however, the space of plausible generative models considered is dramatically limited by the set of models with known likelihood functions. For many models, the lack of a closed-form likelihood typically impedes Bayesian inference methods. Read More

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Greater Reduction in Contralesional Hand Use After Frontoparietal Than Frontal Motor Cortex Lesions in .

Front Syst Neurosci 2021 18;15:592235. Epub 2021 Mar 18.

Division of Basic Biomedical Sciences, Laboratory of Neurological Sciences, The University of South Dakota, Sanford School of Medicine, Vermillion, SD, United States.

We previously reported that rhesus monkeys recover spontaneous use of the more impaired (contralesional) hand following neurosurgical lesions to the arm/hand representations of primary motor cortex (M1) and lateral premotor cortex (LPMC) (F2 lesion) when tested for reduced use (RU) in a fine motor task allowing use of either hand. Recovery occurred without constraint of the less impaired hand and with occasional forced use of the more impaired hand, which was the preferred hand for use in fine motor tasks before the lesion. Here, we compared recovery of five F2 lesion cases in the same RU test to recovery after unilateral lesions of M1, LPMC, S1 and anterior portion of parietal cortex (F2P2 lesion - four cases). Read More

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Female ornaments: is red skin color attractive to males and related to condition in rhesus macaques?

Behav Ecol 2021 Mar-Apr;32(2):236-247. Epub 2021 Jan 28.

Center for the Study of Human Origins, Department of Anthropology, New York University, New York, NY, USA.

Sexual selection produces extravagant male traits, such as colorful ornaments, via female mate choice. More rarely, in mating systems in which males allocate mating effort between multiple females, female ornaments may evolve via male mate choice. Females of many anthropoid primates exhibit ornaments that indicate intraindividual cyclical fertility, but which have also been proposed to function as interindividual quality signals. Read More

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January 2021

ART administration reduces neuroinflammation without restoring BDNF signaling in alcohol-administered SIV-infected macaques.

AIDS 2021 Mar 31. Epub 2021 Mar 31.

Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA Comprehensive Alcohol-HIV/AIDS Research Center, Louisiana State University Health Sciences Center, New Orleans, LA Department of Microbiology, Immunology, and Parasitology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA Biostatistics, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA.

Objective: This study examined interactions between simian immunodeficiency virus (SIV), chronic binge alcohol (CBA), and antiretroviral therapy (ART) on growth factor signaling, neuroinflammatory markers, viral loads (VL), and CD4 counts.

Design: Adult male rhesus macaques were administered CBA (13-14 g EtOH/kg/week) or sucrose (SUC) three months prior to SIVmac251 infection until study endpoint. At viral setpoint, a subset of CBA/SIV+ and SUC/SIV+ macaques were randomized to receive daily ART (PMPA 20 mg/kg, FTC, 30 mg/kg). Read More

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Species Differences in Microsomal Metabolism of Xanthine-Derived A Adenosine Receptor Ligands.

Pharmaceuticals (Basel) 2021 Mar 18;14(3). Epub 2021 Mar 18.

Institute of Neuroscience and Medicine-Nuclear Chemistry (INM-5), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany.

Tracer development for positron emission tomography (PET) requires thorough evaluation of pharmacokinetics, metabolism, and dosimetry of candidate radioligands in preclinical animal studies. Since variations in pharmacokinetics and metabolism of a compound occur in different species, careful selection of a suitable model species is mandatory to obtain valid data. This study focuses on species differences in the in vitro metabolism of three xanthine-derived ligands for the A adenosine receptor (AAR), which, in their F-labeled form, can be used to image AAR via PET. Read More

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Dimethyl Fumarate, an Approved Multiple Sclerosis Treatment, Reduces Brain Oxidative Stress in SIV-Infected Rhesus Macaques: Potential Therapeutic Repurposing for HIV Neuroprotection.

Antioxidants (Basel) 2021 Mar 9;10(3). Epub 2021 Mar 9.

Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.

Dimethyl fumarate (DMF), an antioxidant/anti-inflammatory drug approved for the treatment of multiple sclerosis, induces antioxidant enzymes, in part through transcriptional upregulation. We hypothesized that DMF administration to simian immunodeficiency virus (SIV)-infected rhesus macaques would induce antioxidant enzyme expression and reduce oxidative injury and inflammation throughout the brain. Nine SIV-infected, CD8-T-lymphocyte-depleted rhesus macaques were studied. Read More

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The Subcortical Atlas of the Rhesus Macaque (SARM) for neuroimaging.

Neuroimage 2021 Mar 29;235:117996. Epub 2021 Mar 29.

Centre for Integrative Neurosciences, University of Tübingen, Tübingen, Germany; Max Planck Institute for Biological Cybernetics, Tübingen, Germany; Nathan S. Kline Institute for Psychiatric Research, Center for Biomedical Imaging and Neuromodulation, Orangeburg, NY, USA; International Center for Primate Brain Research, Songjiang, Shanghai, PR China. Electronic address:

Digitized neuroanatomical atlases that can be overlaid onto functional data are crucial for localizing brain structures and analyzing functional networks identified by neuroimaging techniques. To aid in functional and structural data analysis, we have created a comprehensive parcellation of the rhesus macaque subcortex using a high-resolution ex vivo structural imaging scan. This anatomical scan and its parcellation were warped to the updated NIMH Macaque Template (NMT v2), an in vivo population template, where the parcellation was refined to produce the Subcortical Atlas of the Rhesus Macaque (SARM) with 210 primary regions-of-interest (ROIs). Read More

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Shared mechanisms underlie the control of working memory and attention.

Nature 2021 Apr 31;592(7855):601-605. Epub 2021 Mar 31.

Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.

Cognitive control guides behaviour by controlling what, when, and how information is represented in the brain. For example, attention controls sensory processing; top-down signals from prefrontal and parietal cortex strengthen the representation of task-relevant stimuli. A similar 'selection' mechanism is thought to control the representations held 'in mind'-in working memory. Read More

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A continuum of invariant sensory and behavioral-context perceptual coding in secondary somatosensory cortex.

Nat Commun 2021 03 31;12(1):2000. Epub 2021 Mar 31.

Instituto de Fisiología Celular─Neurociencias, Universidad Nacional Autónoma de México, Mexico City, Mexico.

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. Read More

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