Damage to the primary visual cortex (V1) results in visual field deficits on the contralateral side of the world corresponding to the damaged region. Patients with such loss nonetheless show varying residual vision within this apparently blind region, with the neural mechanisms underlying this ability obscured by small study populations. We identified lesions on structural scans from 39 patients (12 female) with hemianopia and occipital lobe damage.
View Article and Find Full Text PDFCharles Bonnet syndrome (CBS) is a condition characterised by visual hallucinations of varying complexity on a background of vision loss. CBS research has gained popularity only in recent decades, despite evidence dating back to 1760. Knowledge of CBS among both the patient and professional populations unfortunately remains poor, and little is known of its underlying pathophysiology.
View Article and Find Full Text PDFDamage to the primary visual cortex causes homonymous visual impairments that appear to benefit from visual discrimination training. However, whether improvements persist without continued training remains to be determined and was the focus of the present study. After a baseline assessment visit, 20 participants trained twice daily in their blind-field for a minimum of six months (median=155 sessions), using a motion discrimination and integration task.
View Article and Find Full Text PDFDamage to the primary visual cortex (V1) or its afferent white matter tracts results in loss of vision in the contralateral visual field that can present as homonymous visual field deficits. Recent evidence suggests that visual training in the blind field can partially reverse blindness at trained locations. However, the efficacy of visual training to improve vision is highly variable across subjects, and the reasons for this are poorly understood.
View Article and Find Full Text PDFBackground: Charles Bonnet syndrome (CBS) is a condition in which people with vision loss experience complex visual hallucinations. These complex visual hallucinations may be caused by increased excitability in the visual cortex that are present in some people with vision loss but not others.
Objectives: We aimed to evaluate the association between γ-aminobutyric acid (GABA) in the visual cortex and CBS.
The efficacy and safety of acalabrutinib plus obinutuzumab and acalabrutinib monotherapy vs zanubrutinib in patients with treatment-naive chronic lymphocytic leukemia/small lymphocytic lymphoma without del(17p) were compared using an unanchored matching-adjusted indirect comparison. Individual patient-level data from ELEVATE-TN (acalabrutinib plus obinutuzumab, n = 162; acalabrutinib monotherapy, n = 163) were weighted to match published aggregate baseline data from SEQUOIA cohort 1, which excluded patients with del(17p) (zanubrutinib, n = 241), using variables that were prognostic/predictive of investigator-assessed progression-free survival (INV-PFS) in an exploratory Cox regression analysis of ELEVATE-TN. After matching, INV-PFS was longer with acalabrutinib plus obinutuzumab (hazard ratio [HR], 0.
View Article and Find Full Text PDFProteomic profiling of protease-generated N termini provides key insights into protease function and specificity. However, current technologies have sequence limitations or require specialized synthetic reagents for N-terminal peptide isolation. Here, we introduce an N terminomics toolbox that combines selective N-terminal biotinylation using 2-pyridinecarboxaldehyde (2PCA) reagents with chemically cleavable linkers to enable efficient enrichment of protein N termini.
View Article and Find Full Text PDFBackground: Damage to the primary visual cortex following an occipital stroke causes loss of conscious vision in the contralateral hemifield. Yet, some patients retain the ability to detect moving visual stimuli within their blind field. The present study asked whether such individual differences in blind field perception following loss of primary visual cortex could be explained by the concentration of neurotransmitters γ-aminobutyric acid (GABA) and glutamate or activity of the visual motion processing, human middle temporal complex (hMT+).
View Article and Find Full Text PDFNeuroscience research has expanded dramatically over the past 30 years by advancing standardization and tool development to support rigor and transparency. Consequently, the complexity of the data pipeline has also increased, hindering access to FAIR data analysis to portions of the worldwide research community. was developed to reduce these burdens and democratize modern neuroscience research across institutions and career levels.
View Article and Find Full Text PDFProtein and peptide N termini are important targets for selective modification with chemoproteomics reagents and bioconjugation tools. The N-terminal ⍺-amine occurs only once in each polypeptide chain, making it an attractive target for protein bioconjugation. In cells, new N termini can be generated by proteolytic cleavage and captured by N-terminal modification reagents that enable proteome-wide identification of protease substrates through tandem mass spectrometry (LC-MS/MS).
View Article and Find Full Text PDFHaving two forward-facing eyes with slightly different viewpoints enables animals, including humans, to discriminate fine differences in depth (disparities), which can facilitate interaction with the world. The binocular visual system starts in the primary visual cortex because that is where information from the eyes is integrated for the first time. Magnetic resonance imaging (MRI) is an ideal tool to non-invasively investigate this system since it can provide a range of detailed measures about structure, function, neurochemistry and connectivity of the human brain.
View Article and Find Full Text PDFPurpose: The scotopic macular integrity assessment (S-MAIA) can perform scotopic assessment to detect localized changes to scotopic rod and cone function. This study is an exploratory investigation of the feasibility of using the S-MAIA in a rod-cone dystrophy population to identify the pattern of loss in scotopic photoreceptor function.
Methods: Twenty patients diagnosed with a rod-cone dystrophy underwent visual acuity testing, full-field stimulus threshold assessment, and multiple S-MAIA tests after dark adaptation periods of 20 minutes and 45 minutes performed separately.
Individuals with congenital blindness due to bilateral anophthalmia offer a unique opportunity to examine cross-modal plasticity in the complete absence of any stimulation of the 'visual' pathway even during development in utero. Our previous work has suggested that this complete sensory deafferentation results in different patterns of reorganisation compared with those seen in other early blind populations. Here, we further test the functional specialisation of occipital cortex in six well-studied cases with anophthalmia.
View Article and Find Full Text PDFPurpose: We aimed to assess the performance of the modified-Esterman test (mET) as a rapid suprathreshold binocular quantification tool for the assessment of peripheral visual fields. The mET consists of an even spread of test points across the visual field.
Materials And Methods: The mET was implemented on the Octopus 0900 perimeter using the Open Perimetry Interface (OPI) and consisted of 160 points.
More inclusive, authentic assessments are required to address awarding gaps and to ensure that bioscience students can apply their knowledge to relevant work-based scenarios. In this case report, we present a co-created approach to designing a more inclusive, virtual biochemistry lab assessment for a diverse cohort of ∼270 first-year students. The assignment was to write up an inclusive clinical case study as a one-page journal article.
View Article and Find Full Text PDFStereoscopic vision enables the perception of depth. To study the brain mechanisms behind stereoscopic vision using noninvasive brain imaging (magnetic resonance brain imaging; MRI), scientists need to reproduce the independent views of the left and right eyes in the brain scanner using "dichoptic" displays. However, high-quality dichoptic displays are technically challenging and costly to implement in the MRI scanner.
View Article and Find Full Text PDFThe visual maps measured non-invasively in the brain of human and non-human primates reliably reflect the underlying neuronal responses recorded with invasive electrodes.
View Article and Find Full Text PDFNoninvasive diffusion-weighted magnetic resonance imaging (dMRI) can be used to map the neural connectivity between distinct areas in the intact brain, but the standard resolution achieved fundamentally limits the sensitivity of such maps. We investigated the sensitivity and specificity of high-resolution postmortem dMRI and probabilistic tractography in rhesus macaque brains to produce retinotopic maps of the lateral geniculate nucleus (LGN) and extrastriate cortical visual area V5/MT based on their topographic connections with the previously established functional retinotopic map of primary visual cortex (V1). We also replicated the differential connectivity of magnocellular and parvocellular LGN compartments with V1 across visual field positions.
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