A rostro-caudal gradient of uranium (U) in the brain has been suggested after its inhalation. To study the factors influencing this mapping, we first used 30-min acute inhalation at 56 mg/m of the relatively soluble form UO in the rat. These exposure parameters were then used as a reference in comparison with the other experimental conditions. Other groups received acute inhalation at different concentrations, repeated low dose inhalation of UO (10 exposures) or acute low dose inhalation of the insoluble form UO. At 24 h after the last exposure, all rats showed a brain U accumulation with a rostro-caudal gradient as compared to controls. However, the total concentration to the brain was greater after repeated exposure than acute exposure, demonstrating an accumulative effect. In comparison with the low dose soluble U exposure, a higher accumulation in the front of the brain was observed after exposure to higher dose, to insoluble particles and following repetition of exposures, thus demonstrating a dose effect and influences of solubility and repetition of exposures. In the last part, exposure to ultrafine U particles made it possible to show 24 h after exposure the presence of U in the brain according to a rostro-caudal gradient. Finally, the time-course after exposure to micronic or nanometric U particles has revealed greater residence times for nanoparticles.
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http://dx.doi.org/10.1016/j.toxlet.2021.08.002 | DOI Listing |
Brain Behav Evol
November 2024
Centre for Behaviour and Evolution, Newcastle University, Newcastle upon Tyne, UK.
Introduction: Different functional domains can be identified along the longitudinal axis of the mammalian hippocampus. We have recently hypothesized that a similar functional gradient may exist along the longitudinal axis of the avian hippocampal formation (HF) as well. If the 2 gradients are homologous, we would expect the caudal HF to be more responsive to acute stress than the rostral HF.
View Article and Find Full Text PDFUnlabelled: The vestibular system is important for posture, balance, motor control, and spatial orientation. Each of the vestibular end organs have specialized neuroepithelia with both regular and irregular afferents. In otolith organs, the utricle and saccule, afferents most responsive to linear jerk (jerk - derivative of acceleration) are located in the striola and project centrally to the vestibular nuclear complex (VNC) as well as the uvula and nodulus of the vestibulocerebellum (VeCb).
View Article and Find Full Text PDFNeuroimage Clin
June 2024
Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, Pacific Parkinson's Research Centre, University of British Columbia & Vancouver Coastal Health, Vancouver, BC, Canada.
Several genetic pathogenic variants increase the risk of Parkinson's disease (PD) with pathogenic variants in the leucine-rich repeat kinase 2 (LRRK2) gene being among the most common. A joint pattern analysis based on multi-set canonical correlation analysis (MCCA) was utilized to extract PD and LRRK2 pathogenic variant-specific spatial patterns in relation to healthy controls (HCs) from multi-tracer Positron Emission Tomography (PET) data. Spatial patterns were extracted for individual subject cohorts, as well as for pooled subject cohorts, to explore whether complementary spatial patterns of dopaminergic denervation are different in the asymptomatic and symptomatic stages of PD.
View Article and Find Full Text PDFMicroPubl Biol
March 2024
Department of Functional Biology, University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain.
RGM interactions with its receptor Neogenin play an important role in the regulation of axonal guidance or cell death in the developing central nervous system. The sea lamprey transcript has been recently identified. However, its expression has been only studied in the spinal cord of mature (premetamorphic) larval sea lampreys.
View Article and Find Full Text PDFElife
August 2023
Department of Neurobiology, Care Sciences and Society, Division of Clinical Geriatrics, Karolinska Institutet, Stockholm, Sweden.
The locus coeruleus (LC) is an important noradrenergic nucleus that has recently attracted a lot of attention because of its emerging role in cognitive and psychiatric disorders. Although previous histological studies have shown that the LC has heterogeneous connections and cellular features, no studies have yet assessed its functional topography in vivo, how this heterogeneity changes over aging, and whether it is associated with cognition and mood. Here, we employ a gradient-based approach to characterize the functional heterogeneity in the organization of the LC over aging using 3T resting-state fMRI in a population-based cohort aged from 18 to 88 years of age (Cambridge Centre for Ageing and Neuroscience cohort, n=618).
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