keyword
https://read.qxmd.com/read/38109611/poster-session-i-digital-dual-purkinje-image-eye-tracking-enables-precise-determination-of-visual-receptive-fields-in-fixating-macaques
#21
JOURNAL ARTICLE
Ryan Ressmeyer, Jacob Yates, Gregory Horwitz
Understanding the relationship between visual stimuli and neural activity is a fundamental goal in visual neuroscience. However, the study of visual neurophysiology in awake primates is complicated by the constant occurrence of eye movements, even during periods of nominal fixation. To address this challenge, we adapted a recently developed high-resolution digital dual-Purkinje-image (dDPI) eye tracker (Wu et al., 2023) for use with macaque monkeys. In addition to tracking the Purkinje images, we simultaneously estimate the pupil center and size: a first for video eye tracking...
December 1, 2023: Journal of Vision
https://read.qxmd.com/read/38047381/the-postnatal-development-of-retinal-projections-in-strepsirrhine-galagos-otolemur-garnettii
#22
JOURNAL ARTICLE
Chia-Chi Liao, Mariana Gabi, Hui-Xin Qi, Jon H Kaas
Here, we describe the postnatal development of retinal projections in galagos. Galagos are of special interest as they represent the understudied strepsirrhine branch (galagos, pottos, lorises, and lemurs) of the primate radiations. The projections of both eyes were revealed in each galago by injecting red or green cholera toxin subunit B (CTB) tracers into different eyes of galagos ranging from postnatal day 5 to adult. In the dorsal lateral geniculate nucleus, the magnocellular, parvocellular, and koniocellular layers were clearly labeled and identified by having inputs from the ipsilateral or contralateral eye at all ages...
December 4, 2023: Journal of Comparative Neurology
https://read.qxmd.com/read/38041431/polioencephalopathy-in-eurasier-dogs
#23
JOURNAL ARTICLE
Faye Rawson, Matthias Christen, Jeremy Rose, Emilie Paran, Tosso Leeb, Angela Fadda
BACKGROUND: Polioencephalopathies secondary to inborn errors of metabolism have been described in dogs, but few genetically characterized. OBJECTIVES: Clinically and genetically characterize polioencephalopathy in a family of Eurasier dogs. ANIMALS: Three Eurasier dogs (littermates) presented with early onset movement disorders (9 weeks in 2, 4-6 months in 1). Progressive gait abnormalities were detected in 2 of the dogs, persistent divergent strabismus in 1, whereas consciousness and behavior remained intact in all dogs...
December 2, 2023: Journal of Veterinary Internal Medicine
https://read.qxmd.com/read/38018655/distinct-alterations-of-retinal-structure-between-thalamic-and-extra-thalamic-subcortical-infarction-patients-a-cross-sectional-and-longitudinal-study
#24
JOURNAL ARTICLE
Ruosu Pan, Chen Ye, Zhimeng Zhang, William Robert Kwapong, Ruilin Wang, Kun Lu, Lanhua Liao, Yuying Yan, Tang Yang, Le Cao, Shuai Jiang, Xuening Zhang, Junfeng Liu, Wendan Tao, Bo Wu
AIMS: Cerebrovascular lesions in the primary visual cortex, the lateral geniculate nucleus, and the optic tract have been associated with retinal neurodegeneration via the retrograde degeneration (RD) mechanism. We aimed to use optical coherence tomography (OCT) to assess the effects of the strategic single subcortical infarction (SSI) location on retinal neurodegeneration and its longitudinal impacts. METHODS: Patients with SSI were enrolled and stratified by lesion location on cerebral MRI into the thalamic infarction group and extra-thalamic infarction group...
November 29, 2023: CNS Neuroscience & Therapeutics
https://read.qxmd.com/read/37995952/model-matters-differential-outcomes-in-traumatic-optic-neuropathy-pathophysiology-between-blunt-and-blast-wave-mediated-head-injuries
#25
JOURNAL ARTICLE
S M Hetzer, C O'Connell, V Lallo, M Robson, N K Evanson
Over 3 million people in the United States live with long-term disability because of a traumatic brain injury (TBI). The purpose of this study was to characterize and compare two different animal models of TBI (blunt head trauma and blast TBI) to determine common and divergent characteristics of these models. With recent literature reviews noting the prevalence of visual system injury in animal models of TBI, coupled with clinical estimates of 50-75% of all TBI cases, we decided to assess commonalities, if they existed, through visual system injury...
November 22, 2023: Experimental Neurology
https://read.qxmd.com/read/37961360/enabling-brain-wide-mapping-of-directed-functional-connectivity-at-3t-via-layer-dependent-fmri-with-draining-vein-suppression
#26
Wei-Tang Chang, Weili Lin, Kelly S Giovanello
Layer-dependent functional magnetic resonance imaging (fMRI) offers a compelling avenue for investigating directed functional connectivity (FC). To construct a comprehensive map of brain-wide directed FC, several technical criteria must be met, including sub-mm spatial resolution, adequate temporal resolution, functional sensitivity, global brain coverage, and high spatial specificity. Although gradient echo (GE)-based echo planar imaging (EPI) is commonly used for rapid fMRI acquisition, it faces significant challenges due to the draining-vein effect, particularly when utilizing blood oxygen level-dependent (BOLD) contrast...
October 29, 2023: bioRxiv
https://read.qxmd.com/read/37954873/in-humans-striato-pallido-thalamic-projections-are-largely-segregated-by-their-origin-in-either-the-striosome-like-or-matrix-like-compartments
#27
JOURNAL ARTICLE
Adrian T Funk, Asim A O Hassan, Norbert Brüggemann, Nutan Sharma, Hans C Breiter, Anne J Blood, Jeff L Waugh
Cortico-striato-thalamo-cortical (CSTC) loops are fundamental organizing units in mammalian brains. CSTCs process limbic, associative, and sensorimotor information in largely separated but interacting networks. CTSC loops pass through paired striatal compartments, striosome (aka patch) and matrix, segregated pools of medium spiny projection neurons with distinct embryologic origins, cortical/subcortical structural connectivity, susceptibility to injury, and roles in behaviors and diseases. Similarly, striatal dopamine modulates activity in striosome and matrix in opposite directions...
2023: Frontiers in Neuroscience
https://read.qxmd.com/read/37949869/enhancement-and-contextual-modulation-of-visuospatial-processing-by-thalamocollicular-projections-from-ventral-lateral-geniculate-nucleus
#28
JOURNAL ARTICLE
Zhong Li, Bo Peng, Junxiang J Huang, Yuan Zhang, Michelle B Seo, Qi Fang, Guang-Wei Zhang, Xiaohui Zhang, Li I Zhang, Huizhong Whit Tao
In the mammalian visual system, the ventral lateral geniculate nucleus (vLGN) of the thalamus receives salient visual input from the retina and sends prominent GABAergic axons to the superior colliculus (SC). However, whether and how vLGN contributes to fundamental visual information processing remains largely unclear. Here, we report in mice that vLGN facilitates visually-guided approaching behavior mediated by the lateral SC and enhances the sensitivity of visual object detection. This can be attributed to the extremely broad spatial integration of vLGN neurons, as reflected in their much lower preferred spatial frequencies and broader spatial receptive fields than SC neurons...
November 10, 2023: Nature Communications
https://read.qxmd.com/read/37938923/topography-of-visual-and-somatosensory-inputs-to-the-pontine-nuclei-in-zebra-finches-taeniopygia-guttata
#29
JOURNAL ARTICLE
Andrea H Gaede, Cristián Gutiérrez-Ibáñez, Pei-Hsuan Wu, Madison C Pilon, Douglas L Altshuler, Douglas R Wylie
Birds have a comprehensive network of sensorimotor projections extending from the forebrain and midbrain to the cerebellum via the pontine nuclei, but the organization of these circuits in the pons is not thoroughly described. Inputs to the pontine nuclei include two retinorecipient areas, nucleus lentiformis mesencephali (LM) and nucleus of the basal optic root (nBOR), which are important structures for analyzing optic flow. Other crucial regions for visuomotor control include the retinorecipient ventral lateral geniculate nucleus (GLv), and optic tectum (TeO)...
November 8, 2023: Journal of Comparative Neurology
https://read.qxmd.com/read/37927121/improved-reconstruction-of-crossing-fibers-in-the-mouse-optic-pathways-with-orientation-distribution-function-fingerprinting
#30
JOURNAL ARTICLE
Patryk Filipiak, Thajunnisa A Sajitha, Timothy M Shepherd, Kamri Clarke, Hannah Goldman, Dimitris G Placantonakis, Jiangyang Zhang, Kevin C Chan, Fernando E Boada, Steven H Baete
PURPOSE: The accuracy of diffusion MRI tractography reconstruction decreases in the white matter regions with crossing fibers. The optic pathways in rodents provide a challenging structure to test new diffusion tractography approaches because of the small crossing volume within the optic chiasm and the unbalanced 9:1 proportion between the contra- and ipsilateral neural projections from the retina to the lateral geniculate nucleus, respectively. METHODS: Common approaches based on Orientation Distribution Function (ODF) peak finding or statistical inference were compared qualitatively and quantitatively to ODF Fingerprinting (ODF-FP) for reconstruction of crossing fibers within the optic chiasm using in vivo diffusion MRI ( <mml:math xmlns:mml="https://www...
November 5, 2023: Magnetic Resonance in Medicine
https://read.qxmd.com/read/37904992/a-neural-modeling-approach-to-study-mechanisms-underlying-the-heterogeneity-of-visual-spatial-frequency-sensitivity-in-schizophrenia
#31
Caroline Dugan, Basilis Zikopoulos, Arash Yazdanbakhsh
Patients with schizophrenia exhibit abnormalities in spatial frequency sensitivity, and it is believed that these abnormalities indicate more widespread dysfunction and dysregulation of bottom-up processing. The early visual system, including the first-order Lateral Geniculate Nucleus of the thalamus (LGN) and the primary visual cortex (V1), are key contributors to spatial frequency sensitivity. Medicated and unmedicated patients with schizophrenia exhibit contrasting changes in spatial frequency sensitivity, thus making it a useful probe for examining potential effects of the disorder and antipsychotic medications in neural processing...
October 21, 2023: bioRxiv
https://read.qxmd.com/read/37886488/short-latency-preference-for-faces-in-the-primate-superior-colliculus
#32
Gongchen Yu, Leor N Katz, Christian Quaia, Adam Messinger, Richard J Krauzlis
UNLABELLED: Face processing is fundamental to primates and has been extensively studied in higher-order visual cortex. Here we report that visual neurons in the midbrain superior colliculus (SC) display a preference for faces, that the preference emerges within 50ms of stimulus onset - well before "face patches" in visual cortex - and that this activity can distinguish faces from other visual objects with accuracies of ∼80%. This short-latency preference in SC depends on signals routed through early visual cortex, because inactivating the lateral geniculate nucleus, the key relay from retina to cortex, virtually eliminates visual responses in SC, including face-related activity...
September 9, 2023: bioRxiv
https://read.qxmd.com/read/37796249/thalamic-regulation-of-ocular-dominance-plasticity-in-adult-visual-cortex
#33
JOURNAL ARTICLE
Yi Qin, Mehran Ahmadlou, Samuel Suhai, Paul Neering, Leander de Kraker, J Alexander Heimel, Christiaan N Levelt
Experience-dependent plasticity in the adult visual system is generally thought of as a cortical process. However, several recent studies have shown that perceptual learning or monocular deprivation can also induce plasticity in the adult dorsolateral geniculate nucleus (dLGN) of the thalamus. How plasticity in the thalamus and cortex interact in the adult visual system is ill-understood. To assess the influence of thalamic plasticity on plasticity in primary visual cortex (V1), we made use of our previous finding that during the critical period ocular dominance (OD) plasticity occurs in dLGN and requires thalamic synaptic inhibition...
October 5, 2023: ELife
https://read.qxmd.com/read/37791662/optogenetic-activation-of-visual-thalamus-generates-artificial-visual-percepts
#34
JOURNAL ARTICLE
Jing Wang, Hamid Azimi, Yilei Zhao, Melanie Kaeser, Pilar Vaca Sánchez, Abraham Vazquez-Guardado, John A Rogers, Michael Harvey, Gregor Rainer
The lateral geniculate nucleus (LGN), a retinotopic relay center where visual inputs from the retina are processed and relayed to the visual cortex, has been proposed as a potential target for artificial vision. At present, it is unknown whether optogenetic LGN stimulation is sufficient to elicit behaviorally relevant percepts, and the properties of LGN neural responses relevant for artificial vision have not been thoroughly characterized. Here, we demonstrate that tree shrews pretrained on a visual detection task can detect optogenetic LGN activation using an AAV2-CamKIIα-ChR2 construct and readily generalize from visual to optogenetic detection...
October 4, 2023: ELife
https://read.qxmd.com/read/37786698/parallel-pathways-carrying-direction-and-orientation-selective-retinal-signals-to-layer-4-of-mouse-visual-cortex
#35
Helen Wang, Oyshi Dey, Willian N Lagos, Noor Behnam, Edward M Callaway, Benjamin K Stafford
Parallel functional and anatomical visual pathways from the retina to primary visual cortex (V1) via the lateral geniculate nucleus (LGN) are common to many mammalian species, including mice, carnivores and primates. However, the much larger number of retinal ganglion cell (RGC) types that project to the LGN, as well as the more limited lamination of both the LGN and the thalamocortical-recipient layer 4 (L4) in mice, leaves considerable uncertainty about which visual features present in both retina and V1 might be inherited from parallel pathways versus extracted by V1 circuits in the mouse visual system...
September 18, 2023: bioRxiv
https://read.qxmd.com/read/37759951/the-ponto-geniculo-occipital-pgo-waves-in-dreaming-an-overview
#36
REVIEW
Jin-Xian Gao, Guizhong Yan, Xin-Xuan Li, Jun-Fan Xie, Karen Spruyt, Yu-Feng Shao, Yi-Ping Hou
Rapid eye movement (REM) sleep is the main sleep correlate of dreaming. Ponto-geniculo-occipital (PGO) waves are a signature of REM sleep. They represent the physiological mechanism of REM sleep that specifically limits the processing of external information. PGO waves look just like a message sent from the pons to the lateral geniculate nucleus of the visual thalamus, the occipital cortex, and other areas of the brain. The dedicated visual pathway of PGO waves can be interpreted by the brain as visual information, leading to the visual hallucinosis of dreams...
September 20, 2023: Brain Sciences
https://read.qxmd.com/read/37746137/characterization-of-extracellular-spike-waveforms-recorded-in-wallaby-primary-visual-cortex
#37
REVIEW
Young Jun Jung, Shi H Sun, Ali Almasi, Molis Yunzab, Hamish Meffin, Michael R Ibbotson
Extracellular recordings were made from 642 units in the primary visual cortex (V1) of a highly visual marsupial, the Tammar wallaby. The receptive field (RF) characteristics of the cells were objectively estimated using the non-linear input model (NIM), and these were correlated with spike shapes. We found that wallaby cortical units had 68% regular spiking (RS), 12% fast spiking (FS), 4% triphasic spiking (TS), 5% compound spiking (CS) and 11% positive spiking (PS). RS waveforms are most often associated with recordings from pyramidal or spiny stellate cell bodies, suggesting that recordings from these cell types dominate in the wallaby cortex...
2023: Frontiers in Neuroscience
https://read.qxmd.com/read/37745616/cone-opponent-ganglion-cells-in-the-primate-fovea-tuned-to-non-cardinal-color-directions
#38
Tyler Godat, Kendall Kohout, Qiang Yang, Keith Parkins, Juliette E McGregor, William H Merigan, David R Williams, Sara S Patterson
A long-standing question in vision science is how the three cone photoreceptor types - long (L), medium (M) and short (S) wavelength sensitive - combine to generate our perception of color. Hue perception can be described along two opponent axes: red-green and blue-yellow. Psychophysical measurements of color appearance indicate that the cone inputs to the red-green and blue-yellow opponent axes are M vs. L+S and L vs. M+S, respectively. However, the "cardinal directions of color space" revealed by psychophysical measurements of color detection thresholds are L vs...
September 16, 2023: bioRxiv
https://read.qxmd.com/read/37745511/differential-cortical-and-subcortical-visual-processing-with-eyes-shut
#39
Nicholas G Cicero, Michaela Klimova, Laura D Lewis, Sam Ling
UNLABELLED: Closing our eyes largely shuts down our ability to see. That said, our eyelids still pass some light, allowing our visual system to coarsely process information about visual scenes, such as changes in luminance. However, the specific impact of eye closure on processing within the early visual system remains largely unknown. To understand how visual processing is modulated when eyes are shut, we used functional magnetic resonance imaging (fMRI) to measure responses to a flickering visual stimulus at high (100%) and low (10%) temporal contrasts, while participants viewed the stimuli with their eyes open or closed...
September 13, 2023: bioRxiv
https://read.qxmd.com/read/37733499/poster-session-the-impact-of-retinal-excitotoxic-lesions-on-parallel-visual-streams-in-the-ferret-dorsal-lateral-geniculate-nucleus
#40
JOURNAL ARTICLE
Jingyi Yang, Krystel Huxlin, Farran Briggs
Attesting to the relative strength of retinal inputs to the dorsal lateral geniculate nucleus (LGN) of the thalamus, in cats, acute retinal lesions erase responses of LGN neurons whose receptive fields fall within the retinal lesion projection zone (LPZ). Yet, thirty days later, these receptive fields appear to shift their representation to the immediate surround of the LPZ. However, little is known about whether LGN neurons in parallel streams are equally affected following retinal damage. Here, we asked whether changes in response properties of surviving LGN neurons depend on (1) their identity as either X/Y or ON/OFF cells, or (2) their receptive fields' positions relative to the LPZ...
September 1, 2023: Journal of Vision
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