Functional and anatomical properties of visual cortex in individuals with congenital loss of cone photoreceptor function and normally sighted controls

The aim of this thesis was to systemically assess reported cortical reorganisation in achromatopsia, a congenital loss of cone photoreceptor function, to inform the current development of vision restoration approaches. Both, functional and structural magnetic resonance imaging (MRI) were used to answer if and to what extend the brain undergoes changes when visual input is lost from birth. First, visual cortical representations of rod and cone driven signals were examined in normally sighted participants to detail differences between these two retinal pathways. We showed that spatial summation properties of the rod pathway are expressed at a cortical level and highlighted that low light levels mainly affect primary visual cortex, while extra striate areas, likely related to their increased spatial pooling properties, still show robust responses. Further, functional MRI showed no differences in cortical responses at central visual field representations between achromats and controls, while achromats that presented with reduced rod function are characterised by a more severe reduction in cortical responses. Notably, traces of remapping in form of an eccentricity shift cannot be ruled out for some participants, Last, this thesis examined brain integrity in achromatopsia using surface-based morphometry and revealed that surface area is reduced across primary visual cortex. Further, patients showed highly localised thickening of the foveal representation in primary visual cortex, supporting the notion of aberrant pruning processes. In summary, findings presented in this thesis allowed insights into cortical mechanisms that maximise sensitivity when visual information is sparse and clearly showed that remapping is not a general feature in achromatopsia while the absence of visual input has distinct effects on cortical structure, comparable to other patient groups with congenital loss of vision

Author Correction: Discovery of 42 genome-wide significant loci associated with dyslexia

Correction to: Nature Genetics https://doi.org/10.1038/s41588-022-01192-y. Published online 20 October 2022. In the version of this article originally published, a paragraph was omitted in the Methods section, reading “Genomic control. Top SNPs are reported from the more conservative GWAS results adjusted for genomic control (Fig. 1, Extended Data Figs. 1–4, and Supplementary Tables 1, 2, 9 and 10), whereas downstream analyses (including gene-set analysis, enrichment and heritability partitioning, genetic correlations, polygenic prediction, candidate gene replication) are based on GWAS results without genomic control.” The paragraph has now been included in the HTML and PDF versions of the article

Structural differences across multiple visual cortical regions in the absence of cone function in congenital achromatopsia

Most individuals with congenital achromatopsia (ACHM) carry mutations that affect the retinal phototransduction pathway of cone photoreceptors, fundamental to both high acuity vision and colour perception. As the central fovea is occupied solely by cones, achromats have an absence of retinal input to the visual cortex and a small central area of blindness. Additionally, those with complete ACHM have no colour perception, and colour processing regions of the ventral cortex also lack typical chromatic signals from the cones. This study examined the cortical morphology (grey matter volume, cortical thickness and cortical surface area) of multiple visual cortical regions in ACHM (n=15) compared to normally sighted controls (n=42) to determine the cortical changes that are associated with the retinal characteristics of ACHM. Surface-based morphometry was applied to T1-weighted MRI in atlas-defined early, ventral and dorsal visual regions of interest. Reduced grey matter volume in V1, V2, V3 and V4 was found in ACHM compared to controls, driven by a reduction in cortical surface area as there was no significant reduction in cortical thickness. Cortical surface area (but not thickness) was reduced in a wide range of areas (V1, V2, V3, TO1, V4 and LO1). Reduction in early visual areas with large foveal representations (V1, V2 and V3) suggests that the lack of foveal input to the visual cortex was a major driving factor in morphological changes in ACHM. However, the significant reduction in ventral area V4 coupled with the lack of difference in dorsal areas V3a and V3b suggest that deprivation of chromatic signals to visual cortex in ACHM may also contribute to changes in cortical morphology. This research shows that the congenital lack of cone input to the visual cortex can lead to widespread structural changes across multiple visual areas

Reflexões sobre a pessoa e a profissão do professor na área da saúde

Este artigo deriva de um conjunto de ideias experimentadas por discentes do Programa de Pós-graduação em Medicina e Ciências da Saúde da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), em uma disciplina que procurou conhecer melhor o docente típico e suas atipias. O texto pretende auxiliar no entendimento de quem é o professor na área da saúde. Discute o sujeito e sua obra, para além do já conhecido modelo centrado na profissão da saúde que exerce e que procura ensinar. Antes de docente, o professor é uma pessoa. Como pessoa, precisa sentir-se estimada e estimar ao outro (aluno). Ao prosperar em seu trabalho, o docente tem compromissos para com o desenvolvimento intelectual e moral de seus alunos e o planejamento de ações para que exerça a percepção crítica da realidade. A relação ensino-aprendizagem com o educando deve favorecer a análise de valores necessários ao convívio social. Na área da saúde, é requisitado ao aluno aprender a fazer, sendo pouca importância referida ao aprender a conhecer, ao aprender a ser ou a viver em comunhão com os pares. É essencial ter a percepção de que o professor necessita, inicialmente, acolher a si próprio: entender quem é ele, como é e porque chegou ali. A construção da identidade profissional docente é um processo contínuo estabelecido pelo domínio de sua área de ensino, pelos conhecimentos pedagógicos voltados à aprendizagem dos alunos e experiência docente, além das relações sociais do cotidiano

Genome-wide analyses of individual differences in quantitatively assessed reading- and language-related skills in up to 34,000 people

The use of spoken and written language is a fundamental human capacity. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30 to 80% depending on the trait. The genetic architecture is complex, heterogeneous, and multifactorial, but investigations of contributions of single-nucleotide polymorphisms (SNPs) were thus far underpowered. We present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures (word reading, nonword reading, spelling, phoneme awareness, and nonword repetition) in samples of 13,633 to 33,959 participants aged 5 to 26 y. We identified genome-wide significant association with word reading (rs11208009, P = 1.098 x 10(-8)) at a locus that has not been associated with intelligence or educational attainment. All five reading-/language-related traits showed robust SNP heritability, accounting for 13 to 26% of trait variability. Genomic structural equation modeling revealed a shared genetic factor explaining most of the variation in word/nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence, and educational attainment. A multivariate GWAS of word/nonword reading, spelling, and phoneme awareness maximized power for follow-up investigation. Genetic correlation analysis with neuroimaging traits identified an association with the surface area of the banks of the left superior temporal sulcus, a brain region linked to the processing of spoken and written language. Heritability was enriched for genomic elements regulating gene expression in the fetal brain and in chromosomal regions that are depleted of Neanderthal variants. Together, these results provide avenues for deciphering the biological underpinnings of uniquely human traits.Peer reviewe

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Genome-wide analyses of individual differences in quantitatively assessed reading- and language-related skills in up to 34,000 people

The use of spoken and written language is a fundamental human capacity. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30-80%, depending on the trait. The genetic architecture is complex, heterogeneous, and multifactorial, but investigations of contributions of single-nucleotide polymorphisms (SNPs) were thus far underpowered. We present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures: word reading, nonword reading, spelling, phoneme awareness, and nonword repetition, in samples of 13,633 to 33,959 participants aged 5-26 years. We identified genome-wide significant association with word reading (rs11208009, p=1.098 x 10-8) at a locus that has not been associated with intelligence or educational attainment. All five reading-/language-related traits showed robust SNP-heritability, accounting for 13-26% of trait variability. Genomic structural equation modelling revealed a shared genetic factor explaining most variation in word/nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence and educational attainment. A multivariate GWAS of word/nonword reading, spelling, and phoneme awareness maximized power for follow-up investigation. Genetic correlation analysis of multivariate GWAS results with neuroimaging traits identified association with the surface area of the banks of the left superior temporal sulcus, a brain region linked to processing of spoken and written language. Heritability was enriched for genomic elements regulating gene expression in the fetal brain, and in chromosomal regions that are depleted of Neanderthal variants. Together, these results provide new avenues for deciphering the biological underpinnings of uniquely human traits