Biology subjects

Schubert, T.

Publications and source records attributed to Schubert, T..

At least 19 recordsLinked to original sources

bioRxiv2026

Magel2 deficiency drives microglial synaptic engulfment and alters neuron-microglia interactions in Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by hypothalamic dysfunction, developmental delay, hyperphagia, and cognitive impairment, yet the cellular mechanisms underlying circuit abnormalities remain unclear. Here, we show that loss of the imprinted gene Magel2 remodels microglial state and function in a mouse model of PWS. Three-dimensional morphometric analysis of hypothalamic microglia revealed reduced structural complexity and contracted territorial domains, emerging early in development and largely independent of obesity. Single-nucleus RNA sequencing of hypothalamic brain tissue identified extensive transcriptional reprogramming involving immune signaling, cellular communication, ribosome function, synaptic organization, and protein translation, with stronger effects in females. Magel2 deficiency also increased microglia-neuron contacts and synaptic engulfment, accompanied by reduced synaptic marker density, suggesting aberrant refinement of hypothalamic circuits. Analyses of human post-mortem hypothalamic tissue from individuals with PWS confirmed microglial structural alterations and increased complement engagement. Ligand-receptor inference further revealed reorganization of microglia-centered communication networks, including altered adhesion, trophic, and immune signaling consistent with enhanced phagocytic states. Together, these findings identify microglial remodeling and increased synaptic engagement as central features of Magel2 deficiency, implicate microglia in hypothalamic circuit dysfunction in PWS, and highlight excessive synaptic pruning as a novel dysfunctional mechanism of PWS.

neuroscience↗

bioRxiv2026

Eyewire II - A connectomic resource for resolving cell types and circuits of the mouse retina

Comprehensive wiring diagrams from electron microscopy (EM) are a powerful tool to understand the inner workings of the brain. The retina is an easily accessible part of the brain that performs complex visual computations. Its thin, layered structure offers a unique opportunity to decipher neural cell types and map their connectivity. A major obstacle has been the limited size of existing retinal EM datasets, which could not resolve rare cell types and neurons with large dendritic arbors. Here, we describe Eyewire II, a large-scale EM dataset covering nearly 1 mm2 of the adult mouse retina - roughly 10-100 times larger than previous retinal EM volumes. Human proofreading of an automated reconstruction has so far yielded more than 8, 000 bipolar cells, 13, 000 amacrine cells, and 4, 000 retinal ganglion cells. Automated detection is complete for synaptic ribbons and in progress for conventional synapses. Prior to EM imaging, visual responses to diverse stimuli - including natural movies - were recorded in a subset of neurons using two-photon Ca2+ imaging, enabling direct alignment of morphological and functional cell type identity. To enable high-throughput, automatic cell typing, we devised a human-in-the-loop approach that combines deep learning with human expert annotations. As a proof-of-principle, we show that morphological features of reconstructed bipolar cells are sufficient to recover all 15 known bipolar cell types with regular, non-overlapping mosaics. Together, these data and tools establish Eyewire II as a shared resource for the field of retina research. Already now, more than 30 laboratories worldwide are contributing proofreading, expert annotations, and software tools, advancing Eyewire II towards a complete cell type catalog and synaptic wiring diagram of a mammalian retina.

neuroscience↗

bioRxiv2026

Computational prediction resolves thousands of homooligomeric phage protein structures

Bacteriophages (phages) play essential roles in microbial systems, yet most phage proteins remain poorly characterised. Protein tertiary and quaternary structure information contributes valuable information about protein function. As many phage proteins function as homooligomers, complexes that consist of multiple identical subunits, there is great interest in computationally predicting their configurations. Here we present a computational framework, the Phage Homomer Level Estimate and Generation Method (PHLEGM) for inferring homooligomeric states directly from the protein sequence by combining AlphaFold-Multimer modelling with inter-subunit interface quality assessment. We proceeded to experimentally validate two out of nine predicted homooligomers using size exclusion chromatography and complementary hydrodynamic techniques. These efforts confirmed our predictions for a dimer and a trimer, highlighting the value of experimentally benchmarked computational predictions and showing the challenges of heterologous phage protein production. Applied to >22,000 phage protein sequences in the PHROGs database, our approach revealed extensive diversity in phage homooligomeric protein complexes. Benchmarking against protein language model-based predictors on a curated reference set of known phage homooligomers demonstrated superior accuracy of our structure-based method, achieving robust performance in classifying protein homooligomeric states, with the highest accuracy observed for trimers and higher-order complexes. These results highlight the value of computational predictions to decipher the complexities of the vast viral sequence space. All predicted complex structures and functional inferences are made publicly available to support structural and functional studies of phage proteins.

microbiology↗

bioRxiv2026

On-Off coding is latent in vertebrate visual circuits

Across sensory systems, neurons often encode stimulus changes of opposite sign as On and Off signals, a fundamental strategy for representing deviations from baseline. In vertebrate vision, this computation is classically attributed to an early, hardwired split in the retina, with segregated pathways subsequently propagated through downstream circuits. Here, we challenge this view. Combining comparative transcriptomics, pharmacology, genetics, in vivo imaging and electrophysiology in zebrafish, with validation in mouse retina, we show that On-Off coding is a latent and intrinsic property of visual circuits. Bipolar cells frequently co-express receptor systems of opposing polarity and can generate mixed responses that are normally suppressed by inhibitory circuitry. Disrupting inhibition or selectively blocking receptor pathways unmasks robust On-Off signalling. In addition, mixed On-Off responses emerge naturally as effective light input increases, including during development and at higher light levels. Across processing stages, including retinal ganglion cells and central neurons, inhibition repeatedly enforces apparent polarity segregation. Thus, polarity splitting is a distributed, dynamically regulated computation rather than a fixed circuit feature. HIGHLIGHTSO_LIMixed On-Off signals are latent across visual processing stages C_LIO_LIInhibition actively sculpts polarity, not just refines it C_LIO_LIPolarity splitting is a dynamic, distributed and reusable computation C_LIO_LIConserved mechanism revealed in zebrafish and mouse C_LI

neuroscience↗

bioRxiv2025

The glycine betaine-cobalamin feedback loop drives cross-feeding between marine bacteria and algae

Heterotrophic bacteria supply cobalt-containing cobalamin (Cbl) to marine microalgae, which in return provide organic substrates. Such metabolic cross-feeding can regulate the species composition of prolific marine plankton and biofilms. Algal-produced glycine betaine (GB) can be catabolized by bacteria using a Cbl-dependent demethylase (MtgBCD). Yet, GBs impact on bacterial Cbl production during cross-feeding, and its control by cobalt scarcity remains elusive. Here, we demonstrate that Phaeobacter inhibens bacteria boost their Cbl production 25-fold when grown in monocultures with GB compared to glucose. During co-cultivation, P. inhibens satisfied the Cbl requirements of Gephyrocapsa huxleyi algae. Transcriptomic analysis of mono- and co-cultures revealed co-expression of mtgBCD and gbcAB genes encoding Cbl-dependent and -independent GB demethylases, respectively. Distinct growth defects of deletion mutants indicate that P. inhibens switches from Cbl-dependent to -independent GB demethylation under cobalt limitation, involving a Cbl riboswitch. Our findings suggest a positive feedback loop in which algal GB release stimulates the bacterial supply of Cbl. We predict the breakdown of this interaction under naturally occurring cobalt limitation which potentially contributes to the transient nature of algal blooms. Comparative genomics indicate that this mechanism is widespread in Rhodobacterales and other abundant marine Alphaproteobacteria, underscoring its pivotal role in global ocean productivity.

microbiology↗

bioRxiv2025

A large-scale dataset of functional mouse ganglion cell layer responses

We present the AO_SCPLOWLLC_SCPLOW-GCL dataset, a large-scale resource of functional two-photon Ca2+-imaging recordings with rich meta-data information from more than 80,000 cells in the ganglion cell layer (GCL) of the ex vivo mouse retina. Collected over nine years across more than 139 experimental sessions, the dataset provides recordings of light-evoked responses to various stimuli, including a shared set of core stimuli. To enable cell-type-specific analyses, cells are probabilistically assigned to 46 previously characterized functional groups, including retinal ganglion cells and displaced amacrine cells. Further, we assessed the influence of experimental and biological factors on the functional responses and found only small batch effects across experimenters, setups, and recording sessions, highlighting the datasets consistency. The AO_SCPLOWLLC_SCPLOW-GCL dataset offers a comprehensive and standardised reference for studying retinal computation at scale. It supports population-level analyses, computational modelling, and the development of machine learning approaches for biological time-series data. Future releases will expand the dataset with additional mouse lines and light stimuli, creating a growing resource for the vision science community.

neuroscience↗

bioRxiv2025

Bacterial community adaptation after freshwater and seawater coalescence

Microbial community coalescence, the merging of entire microbial communities, is common across ecosystems, particularly in estuaries where freshwater and seawater mix. The complexity of these habitats makes the in situ study of community dynamics after coalescence challenging, highlighting the need for controlled experiments to unravel the factors influencing the coalescence in the estuary. To study these processes, we combined natural freshwater and seawater bacterial communities at five different mixing ratios and incubated them in parallel microcosms containing freshwater or seawater incubation media. Forty mixed communities were tracked over six passages using Nanopore full-length 16S rRNA gene sequencing. In the original field samples, freshwater hosted more diverse communities than seawater. While the communities were structurally distinct, shared bacterial families accounted for approximately 95% of total reads. Many low-abundance taxa were lost upon laboratory incubation, while potentially faster-growing ones were enriched. We found that the coalescence outcome was strongly shaped by the incubation media, whereas the mixing ratio had a minor influence. Mixed communities converged toward the source community native to the incubation media, with increasing similarity at a higher source community proportion. In freshwater, a 25% inoculum of the freshwater community was sufficient to re-establish a near-native freshwater community, whereas in seawater, similarity to the native seawater community depended on the inoculation ratio. Network analysis showed a tightly connected module of seawater families, reflecting their shared habitat preference or cooperation, whereas freshwater families were more loosely connected. We also observed that most families were unaffected by mixing ratios or temporal dynamics, with only a few showing mixing ratio dependence. For instance, the freshwater family Comamonadaceae and seawater families Marinomonadaceae and Pseudoalteromonadaceae were dominant in their respective native environments, and increased in mixed communities in proportion to their initial source proportion. Overall, environmental filtering had a stronger impact than the mixing ratio of source communities on coalesced communities, with habitat-specific taxa further modulating the outcome. These findings advanced our understanding of microbial responses to coalescence and provided insights into microbial community assembly in dynamic estuarine systems. HighlightsO_LIEnvironmental filtering outweighs the microbial source community ratio in shaping coalescence outcomes. C_LIO_LIAsymmetric resilience: freshwater communities require a lower inoculum to re-establish than seawater communities. C_LIO_LIModularity of the seawater source community was observed during coalescence. C_LIO_LIFull-length 16S rRNA gene profiling with a custom dual-barcoding Nanopore protocol enables cost-effective bacterial community tracking. C_LIO_LIControlled coalescence experiments offer mechanistic insights into estuarine microbial community transitions. C_LI

ecology↗

bioRxiv2025

FOXP1 differentially regulates the development of murine vasopressin and oxytocin magnocellular neurons

The neuropeptides arginine vasopressin (AVP) and oxytocin (OXT) are closely related. As neurohormones, AVP and OXT are mainly produced in magnocellular neurons (MCNs) located in the hypothalamus. Development of both neuron types requires coordinated expression of transcription factors OTP, SIM1, ARNT2 and POU3F2. However, the exact transcription factors involved in the diferential diferentiation of the AVP and OXT lineages are yet unknown. We used a publicly available single-cell RNA-sequencing dataset of the developing mouse hypothalamus to identify gene regulatory networks linked to AVP and OXT neuronal diferentiation. We identified RORA, EBF3, FOXP1, FOXP2, and BCL11B as transcription factors with possible relevance for Avp and Oxt MCN divergence. We then modeled developmental gene expression dynamics using computational cell fate mapping. This revealed enrichment of EBF3 and BCL11B in the Avp lineage, while FOXP1 and FOXP2 are enriched in the Oxt lineage. Next, in silico analysis of Avp and Oxt promoters found predicted binding sites for FOXP1 and FOXP2 in the Oxt promoter, suggesting a role in Oxt MCN diferentiation. Finally, we validated the role of one candidate (FOXP1) with a heterozygous knockout mouse line. Compared to wild-type littermates, we find decreased AVP and OXT neuron abundance, with OXT neurons disproportionally afected.

neuroscience↗

bioRxiv2024

Oxytocin Gαi signaling-induced amygdala astrocytes processes retraction shapes behavioral stress response

Anticipated reactions to stressful situations are vital for the survival and well-being of organisms, and abnormal reactions are involved in stress-related disorders. The neuropeptide oxytocin is a key modulator ensuring well-adapted stress responses. Oxytocin acts on both neurons and astrocytes, but the molecular and cellular mechanisms mediating stress response remain poorly understood. Here, we focus on the amygdala, a crucial hub that integrates and processes sensory information through oxytocin- dependent mechanisms. Using an acute stress paradigm in mice, genetic and pharmacological manipulations combined with proteomic, morphological, electrophysiological and behavioral approaches, we reveal that oxytocinergic modulation of the freezing response to stress is mediated by transient Gi-dependent retraction of astrocytic processes, followed by enhanced neuronal sensitivity to extracellular potassium in the amygdala. Our findings elucidate a pivotal role for astrocytes morphology- dependent modulation of brain circuits that is required for proper anticipated behavioral response to stressful situations.

neuroscience↗

bioRxiv2024

Photoreceptor degeneration has heterogeneous effects on functional retinal ganglion cell types

Retinitis pigmentosa is a hereditary disease causing progressive degeneration of rod and cone photoreceptors, with no effective therapies. Using the rd10 mouse model, which mirrors the human condition, we examined its disease progression. Rods deteriorate by postnatal day (P) 45, followed by cone degeneration, with most photoreceptors lost by P180. Until then, retinal ganglion cells (RGCs) remain light-responsive, albeit only under photopic conditions, despite extensive outer retinal remodelling. However, it is still unknown whether the different functional RGC types remain stable, or if some types differentially alter their activity or are even lost during disease progression. Here, we addressed if and how the response diversity of functional RGC types changes with rd10 disease progression. At P30, we were able to identify all functional wild-type RGC types also in rd10 retina, suggesting that at this early degenerative stage, the full breadth of retinal output is still present. Remarkably, we found that the fractions of functional types changed throughout progressing degeneration between rd10 and wild-type: Responses of RGCs with Off-components ( Off and On-Off RGCs) seemed to be more vulnerable than On-cells, with Fast-On types being the most resilient. Notably, direction-selective RGCs appeared to be more vulnerable than orientation-selective RGCs. In summary, we found differences in resilience of response types (from resilient to vulnerable): Uncertain > Fast On > Slow On > On-Off > Off. Taken together, our results suggest that rd10 photoreceptor degeneration has heterogeneous effects on functional RGC types, with distinct sets of types losing their characteristic light responses earlier than others. This differential susceptibility of RGC circuits may be of relevance for future neuroprotective therapeutic strategies.

neuroscience↗

bioRxiv2024

Oxytocin facilitates social behavior of female rats via selective modulation of interneurons in the medial prefrontal cortex

The hypothalamic neuropeptide oxytocin is best known for its prosocial behavioral effects. However, the precise anatomical and cellular targets for oxytocin in the cortex during social behavior remain elusive. Here we show that oxytocin neurons project directly to the medial prefrontal cortex where evoked axonal oxytocin release facilitates social behaviors in adult female rats. In conjunction, we report that local oxytocin receptor-expressing (OTR+) cells are predominantly interneurons, whose activation promotes social interaction. Notably, this prosocial effect persists even under physiological challenge (hunger), pointing to a dedicated prosocial circuit capable of overriding primary survival drives. We further demonstrate that activation of these OTR+ interneurons inhibits principal cells specifically projecting to the basolateral amygdala, thus providing a putative mechanism of selective oxytocin action in this sociability-promoting cortical network.

neuroscience↗

bioRxiv2024

KIRA6 is an effective and versatile mast cell inhibitor of IgE-mediated activation

Incidents of IgE-mediated, mast cell (MC)-driven allergic diseases are constantly rising and there is an urgent need for the development of novel pharmacological MC stabilizers. Allergen/antigen (Ag)-triggered activation of MCs via crosslinking of the high-affinity receptor for IgE (Fc{varepsilon}RI) is regulated, amongst others, by the coordinated action of various cytosolic tyrosine kinases of the SRC family, e.g. LYN and FYN, which exert positive as well as negative functions. We report that KIRA6, an inhibitor developed for the endoplasmic reticulum (ER) stress sensor IRE1, suppresses IgE-mediated pro-inflammatory MC activation by inhibiting both LYN and FYN. KIRA6 dose-dependently and effectively attenuates Ag-stimulated early signaling (e.g. substrate tyrosine phosphorylation, Ca2+ mobilization, and activation of MAPK pathways) as well as effector functions such as degranulation and pro-inflammatory cytokine production/secretion in murine bone marrow-derived MCs (BMMCs). Moreover, Ag-triggered bronchoconstriction in an ex vivo model of precision-cut lung slices (PCLS), and IgE-mediated stimulation of human MCs were repressed by KIRA6. To get in-depth inside into KIRA6 interaction with three MC-relevant tyrosine kinases, LYN, FYN, and KIT, and to elicit the potential of KIRA6 structure to serve as pharmacophore for the development of respective single-, dual-, or triple-specificity inhibitors, we modeled and evaluated the binding of KIRA6 on the three kinases by applying homology modeling and molecular dynamics simulations, as well as MM GBSA calculations. We found that KIRA6 has a high propensity to bind the inactive state of LYN, FYN, and KIT with comparable affinities. In conclusion, our data suggest the use of novel inhibitors based on the KIRA6 pharmacophore as effective MC stabilizers to improve treatment of pro-inflammatory diseases with MC involvement in need of effective pharmacological interventions.

immunology↗

bioRxiv2024

Sustained ON alpha retinal ganglion cells in the temporal retina exhibit task-specific regional adaptions in dendritic signal integration

Various retinal ganglion cells (RGCs) show regional adaptations, for instance, to increase visual acuity. However, for many RGC types, it is not known how they vary in their signalprocessing properties across the retina. In the mouse retina, sustained ON alpha (sON) RGCs were found to have differences in morphology and receptive field sizes along the nasotemporal axis, and temporal sON RGCs are likely to play a role in visually guided hunting. Thus, we hypothesised that this cell type also exhibits regional adaptations on the level of dendritic signal processing and that these adaptations are advantageous for prey capture. Here, we measured dendritic signals from individual sON RGCs at different locations in the exvivo whole-mount mouse retina using two-photon microscopy. We measured both postsynaptic Ca2+ signals at the dendrites of individual RGCs and presynaptic glutamate signals from bipolar cells (BCs). We found that temporal sON RGC dendrites exhibit, in addition to the expected sustained-ON signals with only weak surrounds, signals with strong surround suppression, which were not present in nasal sON RGCs. This difference was also present in the excitatory presynaptic inputs from BCs, suggesting a presynaptic origin. Finally, using population models in an encoder-decoder paradigm, we showed that these adaptations might be beneficial for detecting crickets in hunting behaviour.

neuroscience↗

bioRxiv2024

GABAergic amacrine cells balance biased chromatic information in the mouse retina

The retina extracts chromatic information present in an animals environment. In the mouse, the feed-forward, excitatory pathway through the retina is dominated by a chromatic gradient, with green and UV signals primarily processed in the dorsal and ventral retina, respectively. However, at the output of the retina, chromatic tuning is more mixed, suggesting that amacrine cells alter spectral tuning. We genetically targeted the population of 40+ GABAergic amacrine cell types and used two-photon calcium imaging to systematically survey chromatic responses in their dendritic processes. We found that amacrine cells show diverse chromatic responses in different spatial regions of their receptive fields and across the dorso-ventral axis of the retina. Compared to their excitatory inputs from bipolar cells, amacrine cells are less chromatically tuned and less likely to be colour-opponent. We identified 25 functional amacrine cell types that, in addition to their chromatic properties, exhibit distinctive achromatic receptive field properties. A combination of pharmacological interventions and a biologically-inspired deep learning model revealed how lateral inhibition and recurrent excitatory inputs shape chromatic properties of amacrine cells. Our data suggest that amacrine cells balance the strongly biased spectral tuning of excitation in the mouse retina and thereby support increased diversity in chromatic information of the retinal output.

neuroscience↗

bioRxiv2024

Enhanced cardiac mitochondrial biogenesis by nitro-oleic acid remedies diastolic dysfunction in a mouse model of heart failure with preserved ejection fraction

Prevalence of heart failure with preserved ejection fraction (HFpEF) is increasing, while treatment options are inadequate. Hypertension and obesity-related metabolic dysfunctions contribute to HFpEF progression. Nitro-oleic acid (NO2-OA) impacts metabolic processes by improving glucose tolerance and adipocyte function. In this study, 4 week treatment with NO2-OA ameliorated diastolic dysfunction in a HFpEF mouse model induced by high-fat diet and inhibition of the endothelial nitric oxide synthase. A proteomic analysis of left ventricular tissue revealed, that one third of the identified proteins, mostly mitochondrial proteins, were upregulated in hearts of NO2-OA-treated HFpEF mice compared to controls and vehicle-treated HFpEF mice, which was confirmed by immunoblot. Activation of the 5-adenosine-monophosphate-activated-protein-kinase (AMPK) signaling pathway mediated an enhancement of mitochondrial biogenesis in hearts of NO2-OA-treated HFpEF mice. In cardiomyocytes under metabolic stress, NO2-OA increased mitochondrial protein level accompanied by enhanced oxidative phosphorylation. In conclusion, targeting mitochondrial integrity in HFpEF leads to improved diastolic function.

pathology↗

bioRxiv2023

A comparative analysis of planarian genomes reveals regulatory conservation in the face of rapid structural divergence

The planarian Schmidtea mediterranea can regenerate its entire body from small tissue fragments and is studied as regeneration model species. The assembly and functional analysis of planarian genomes has proven challenging due its high A/T content (70% A/T), repetitive nature, and limited transferability of routine laboratory protocols due to their divergent biochemistry. Only few and often fragmented genome assemblies are currently available, and open challenges include the provision of well-annotated chromosome-scale reference assemblies of the model species and other planarians for a comparative genome evolution perspective. Here we report a haplotype-phased, chromosome-scale genome assembly and high-quality gene annotations of the sexual S2 strain of S. mediterranea and provide putative regulatory region annotations via optimized ATAC-seq and ChIP-seq protocols. To additionally leverage sequence conservation for regulatory element annotations, we generated chromosome-scale genome assemblies and chromatin accessibility data for the three closest relatives of S. mediterranea: S. polychroa, S. nova, and S. lugubris. We find substantial divergence in protein-coding sequences and regulatory regions, yet reveal remarkable conservation in ChIP-mark bearing open chromatin regions identified as promoters and enhancers in S. mediterranea. The resulting high-confidence set of evolutionary conserved enhancers and promoters provides a valuable resource for the analysis of gene regulatory circuits and their evolution within the taxon. In addition, our four chromosome-scale genome assemblies provide a first comparative perspective on planarian genome evolution. Our analyses reveal frequent retrotransposon-associated chromosomal inversions and inter-chromosomal translocations that lead to a degradation of synteny across the genus. Interestingly, we further find independent and near-complete losses of the ancestral metazoan synteny across Schmidtea and two other flatworm groups, indicating that platyhelminth genomes largely evolve without syntenic constraints. Our work provides valuable genome resources for the planarian research community and sets a foundation for the comparative genomics of planarians. We reveal a contrast between the fast structural evolution of planarian genomes and the conservation of their regulatory elements, suggesting a unique genome evolution in flatworms where gene positioning may not be essential.

genomics↗

bioRxiv2023

Nitric oxide mediates differential effects in mouse retinal ganglion cells

Neuromodulators have major influences on the regulation of neural circuit activity across the nervous system. Nitric oxide (NO) has been shown to be a prominent neuromodulator in many circuits and has been extensively studied in the retina. Here, it has been associated with the regulation of light adaptation, gain control, and gap junctional coupling, but its effect on the retinal output, specifically on the different types of retinal ganglion cells (RGCs), is still poorly understood. In this study, we used two-photon Ca2+imaging and multi-electrode array (MEA) recordings to measure light-evoked activity of RGCs in the ganglion cell layer in the ex vivo mouse retina. This approach allowed us to investigate the neuromodulatory effects of NO on a cell type-level. Our findings reveal that NO selectively modulates the suppression of temporal responses in a distinct subset of contrast-suppressed RGC types, increasing their activity without altering the spatial properties of their receptive fields. Given that under photopic conditions, NO release is triggered by quick changes in light levels, we propose that these RGC types signal fast contrast changes to higher visual regions. Remarkably, we found that about one-third of the RGC types, recorded using two-photon Ca2+imaging, exhibited consistent, cell type-specific adaptational response changes throughout an experiment, independent of NO. By employing a sequential-recording paradigm, we could disentangle those additional adaptational response changes from drug-induced modulations. Taken together, our research highlights the selective neuromodulatory effects of NO on RGCs and emphasizes the need of considering non-pharmacological activity changes, like adaptation, in such study designs.

neuroscience↗

bioRxiv2023

Preserved recognition of basic visual features despite lack of awareness of shape: evidence from a case of neglect

Human visual experience of objects comprises a combination of different visual features, such as their color, position, and shape. Spatial attention is thought to play a role in creating a coherent perceptual experience, integrating visual information coming from a given location, but the mechanisms underlying this process are not entirely understood. Deficits of spatial attention in which this integration process does not occur normally, such as neglect, can provide insights regarding the mechanisms of spatial attention in visual object recognition. In this study, we describe a series of experiments conducted with an individual with neglect, XX. XX presents characteristic lack of awareness of the left side of individual objects, evidenced by poor object and face recognition, and impaired word reading. However, he exhibits intact recognition of color within the boundaries of the same objects he fails to recognize. Furthermore, he can also report the orientation and location of a colored region on the neglected left side despite lack of awareness of the shape of the region. To our knowledge, selective lack of awareness of shape despite intact processing of basic visual features in the same spatial location has not been reported previously. XXs performance raises intriguing questions and challenges about the role of spatial attention in the formation of coherent object percepts and visual awareness.

neuroscience↗