Experiments were conducted to elucidate the role of the noradrenergic neurotransmitter system in arousal and the orienting of attention. Rhesus monkeys were trained to perform a peripherally cued, covert orienting task for juice reward, and their manual reaction times (RTs) to visual stimuli were measured. The effects of parenteral injections of the alpha-2 adrenergic agonists clonidine and guanfacine, and normal saline were compared on the covert task. We assessed 1) overall error rates, 2) the difference in RTs between validly and invalidly cued trials (validity effect), 3) the difference in RTs between neutral and no-cue trials (alerting effect), 4) target location (visual field), and 5) cue-target interval. Changes in noradrenaline levels produced by clonidine (and to a lesser extent guanfacine) significantly decreased the alerting effect, and lowered RTs to stimuli in the left visual field, but did not change the validity effect, suggesting that noradrenaline is involved in maintaining non-spatial, sensory readiness to external cues but not in the shifting of the attentional focus.
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Mol Autism
January 2025
Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK.
Background: Significant progress has been made in elucidating the genetic underpinnings of Autism Spectrum Disorder (ASD). However, there are still significant gaps in our understanding of the link between genomics, neurobiology and clinical phenotype in scientific discovery. New models are therefore needed to address these gaps.
View Article and Find Full Text PDFIntroduction: The developed domestic retrodipeptide analogue of cholecystokinin tetrapeptide (CCK) (N-(6-phenylhexanoyl)-glycyltryptophan amide, or compound GB-115) with antagonistic properties in relation to CCK1 receptors has anxiolytic activity previously shown in preclinical and clinical studies. The aim of the study was to evaluate the anxiolytic effect of GB-115 as a tablet form with subchronic oral administration in comparison with phenazepam in nonhuman primates.
Materials And Methods: The study was conducted on four male rhesus monkeys (Macaca mulatta) aged 5.
Sci Rep
January 2025
Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Otfried-Müller Str. 25, 72076, Tübingen, Germany.
Microsaccades are associated with enhanced visual perception and neural sensitivity right before their onset, and this has implications for interpreting experiments involving the covert allocation of peripheral spatial attention. However, the detailed properties of premicrosaccadic enhancement are not fully known. Here we investigated how such enhancement in the superior colliculus depends on luminance polarity.
View Article and Find Full Text PDFPLoS Pathog
January 2025
Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health; Bethesda, Maryland, United States of America.
Viral infections of the central nervous system (CNS) are a major cause of morbidity largely due to lack of prevention and inadequate treatments. While mortality from viral CNS infections is significant, nearly two thirds of the patients survive. Thus, it is important to understand how the human CNS can successfully control virus infection and recover.
View Article and Find Full Text PDFCommun Biol
January 2025
Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA.
The primary immune constituents in the brain, microglia and macrophages, are the target for HIV in people and simian immunodeficiency virus (SIV) in nonhuman primates. This infection can lead to neurological dysfunction, known as HIV-associated neurocognitive disorder (HAND). Given the gaps in our knowledge on how these cells respond in vivo to CNS infection, we perform single-cell multiomic sequencing, including gene expression and ATAC-seq, on myeloid cells from the brains of rhesus macaques with SIV-induced encephalitis (SIVE) as well as uninfected controls.
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