Nonsensory variables strongly influence neuronal activity in the adult mouse primary visual cortex. Neuronal responses to visual stimuli are modulated by behavioural state, such as arousal and motor activity, and are shaped by experience. This dynamic process leads to neural representations in the visual cortex that reflect stimulus familiarity, expectations of reward and object location, and mismatch between self-motion and visual-flow. The recent development of genetic tools and recording techniques in awake behaving mice has enabled the investigation of the circuit mechanisms underlying state-dependent and experience-dependent neuronal representations in primary visual cortex. These neuronal circuits involve neuromodulatory, top-down cortico-cortical and thalamocortical pathways. The functions of nonsensory signals at this early stage of visual information processing are now beginning to be unravelled.
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http://dx.doi.org/10.1016/j.conb.2018.04.020 | DOI Listing |
J Vis
January 2025
Department of Psychology, University of Washington, Seattle, WA, USA.
The population receptive field (pRF) method, which measures the region in visual space that elicits a blood-oxygen-level-dependent (BOLD) signal in a voxel in retinotopic cortex, is a powerful tool for investigating the functional organization of human visual cortex with fMRI (Dumoulin & Wandell, 2008). However, recent work has shown that pRF estimates for early retinotopic visual areas can be biased and unreliable, especially for voxels representing the fovea. Here, we show that a log-bar stimulus that is logarithmically warped along the eccentricity dimension produces more reliable estimates of pRF size and location than the traditional moving bar stimulus.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Lawrence Chen Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
Background: Abnormal tau protein accumulation selectively affects distinct brain regions and specific neuron and glia populations in tau-related dementias like Alzheimer's disease (AD), frontotemporal dementia (FTD, Pick's disease type), and Progressive supranuclear palsy (PSP). The regulatory mechanisms governing cell-type vulnerability remain unclear.
Method: In a cross-disorder single-nucleus analysis, we examined 663,896 nuclei, assessing chromatin accessibility in three brain regions (motor cortex, visual cortex and insular cortex) across PSP, AD, and FTD in 40 individuals.
Alzheimers Dement
December 2024
University of California, Irvine, Irvine, CA, USA.
Alzheimers Dement
December 2024
Cornell University, Ithaca, NY, USA.
Background: Alzheimer's disease (AD) is characterized by progressive, irreversible neurodegeneration, leading to memory loss and cognitive decline. In mouse models of AD, global decreases in cerebral blood flow (CBF) are brought on by the plugging of capillaries by arrested neutrophils, and the administration of the neutrophil-specific antibody against Ly6G (anti-Ly6G) reduces these capillary stalls in minutes and improves cognitive function within hours. This suggests that at least some aspects of neural activity impairment are reversible, but the mechanism of this recovery - and what specific neural activity is normalized - is not yet known.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Background: In Alzheimer's disease (AD), specific brain regions become vulnerable to pathology while others remain resilient. New methods of imaging such as highly multiplexed immunofluorescence (MxIF) provide an abundance of spatial information, while analytical techniques like machine learning (ML) can address questions of cellular contributors to this regional vulnerability.
Method: We performed MxIF staining for 26 markers and compared postmortem human samples from an AD-susceptible brain area, the prefrontal cortex (PFC, Brodmann's areas 9, 10 or 46) to an AD-resilient brain area, the primary visual cortex (V1, area 17).
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