An evolutionary hallmark of anthropoid primates, including humans, is the use of vision to guide precise manual movements. These behaviors are reliant on a specialized visual input to the posterior parietal cortex. Here, we show that normal primate reaching-and-grasping behavior depends critically on a visual pathway through the thalamic pulvinar, which is thought to relay information to the middle temporal (MT) area during early life and then swiftly withdraws. Small MRI-guided lesions to a subdivision of the inferior pulvinar subnucleus (PIm) in the infant marmoset monkey led to permanent deficits in reaching-and-grasping behavior in the adult. This functional loss coincided with the abnormal anatomical development of multiple cortical areas responsible for the guidance of actions. Our study reveals that the transient retino-pulvinar-MT pathway underpins the development of visually guided manual behaviors in primates that are crucial for interacting with complex features in the environment.
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http://dx.doi.org/10.1073/pnas.1717016115 | DOI Listing |
Front Neurol
January 2025
Graduate School, Beijing University of Chinese Medicine, Beijing, China.
Objective: To compare the magnetic resonance imaging (MRI) features of the olfactory cleft (OC) and olfactory bulbs (OBs) in patients with long COVID-19-related (LCOD) and non-COVID-19 postviral olfactory dysfunction (NCPVOD) to explore mechanisms underlying persistent olfactory dysfunction.
Methods: This retrospective analysis included patients diagnosed with LCOD or NCPVOD at the China-Japan Friendship Hospital between February 2023 and July 2024. All patients underwent olfactory psychophysical testing (Sniffin' Sticks), a visual analogue scale (VAS) for olfactory function, and high-resolution MRI scans of the olfactory pathway.
Front Endocrinol (Lausanne)
January 2025
Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Background: Insulin resistance is tightly related to cognition; however, the causal association between them remains a matter of debate. Our investigation aims to establish the causal relationship and direction between insulin resistance and cognition, while also quantifying the mediating role of brain cortical structure in this association.
Methods: The publicly available data sources for insulin resistance (fasting insulin, homeostasis model assessment beta-cell function and homeostasis model assessment insulin resistance, proinsulin), brain cortical structure, and cognitive phenotypes (visual memory, reaction time) were obtained from the MAGIC, ENIGMA, and UK Biobank datasets, respectively.
Cureus
January 2025
Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, GBR.
Background: Obsessive-compulsive disorder (OCD) is a complex condition marked by persistent distressing thoughts and repetitive behaviours. Despite its prevalence, the mechanisms behind OCD remain elusive, and current treatments are limited. This protocol outlines an investigative study for individuals with OCD, exploring the potential of psilocybin to improve key components of cognition implicated in the disorder.
View Article and Find Full Text PDFSci Rep
January 2025
Support Centre for Advanced Neuroimaging (SCAN), Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
This study aims to establish an imitation task of multi-finger haptics in the context of regular grasping and regrasping processes during activities of daily living. A video guided the 26 healthy, right-handed volunteers through the three phases of the task: (1) fixation of a hand holding a cuboid, (2) observation of the sensori-motor manipulation, (3) imitation of that motor action. fMRI recorded the task; graph analysis of the acquisitions revealed the associated functional cerebral connectivity patterns.
View Article and Find Full Text PDFArq Bras Oftalmol
January 2025
Research Nucleus in Neuroscience and Behavior and Applied Neuroscience, Universidade de São Paulo, São Paulo, SP, Brazil.
Purpose: Amblyopia is a cortical neurological disorder caused by abnormal visual experiences during the critical period for visual development. Recent works have shown that, in addition to the well-known visual alterations, such as changes in visual acuity, several perceptual aspects of vision are affected. This study aims to analyze and compare the effects of different types of amblyopia on visual color processing and determine whether these effects are correlated with visual acuity.
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