Biology subjects

Alivodej, N.

Publications and source records attributed to Alivodej, N..

3 recordsLinked to original sources

bioRxiv2026

Vascular signals coordinate cerebellar circuitry development

Neural circuit assembly requires precise coordinated interactions between developing neurons and the vasculature, yet the instructive signals provided by endothelial cells remain largely unknown. Here, we identify a vascular-to-neural signaling axis that orchestrates postnatal cerebellar development. Endothelial-specific deletion of the adaptor protein Dab1 in mice disrupted vascular patterning and uncoupled the growth of major cerebellar neuronal populations. We show that endothelial Dab1 in the cerebellum drives secretion of the morphogen Wnt5a, which acts through Frizzled-2 to restrain granule-cell progenitor proliferation and promote Purkinje-cell dendritic maturation. Endothelial Wnt5a deletion phenocopied Dab1 endothelial mutant (Dab1i{Delta}EC) defects, whereas exogenous Wnt5a restored normal progenitor dynamics in Dab1i{Delta}EC cerebellar slices, demonstrating pathway sufficiency. Functionally, loss of this vascular signal impaired Purkinje-cell firing, diminished parallel-fiber input, reduced synapse formation from both parallel and climbing fibers, and disrupted long-term plasticity. These findings reveal a key instructive role for blood vessels in shaping cerebellar architecture and establishing functional circuit connectivity.

neuroscience↗

bioRxiv2024

Vascular FLRT2 regulates venous-mediated angiogenic expansion and CNS barriergenesis

Veins have emerged as the origin of all other endothelial cell subtypes needed to expand vascular networks during developmental and pathological neoangiogenesis. Here, we uncover the significant role of the angioneurin Fibronectin Leucine Rich Transmembrane protein (FLRT) 2 in central nervous system (CNS) vascular development in the mouse. Early postnatal FLRT2 deletion reveals specific defects in retinal veins, impacting endothelial cell proliferation, sprouting and polarity that result in reduced tip cells at the vascular front. FLRT2 interacts with VE-cadherin and together with the endocytic adaptor protein Numb contribute to the modulation of adherens junction morphology in both retina and cerebral cortex in vivo. Utilizing expansion microscopy, we visualize the altered dynamic distribution of VE-cadherin in tissue of FLRT2 endothelial mutants. Additionally, FLRT2 in cortical vessels regulates the crosstalk between adherens and tight junctions, influencing blood-brain barrier development. Our findings position FLRT2 as a vein-specific crucial regulator of CNS vascular development.

neuroscience↗

bioRxiv2021

Organizing Principles of Astrocytic Nanoarchitecture in the Mouse Cerebral Cortex

Astrocytes have complex roles in central nervous system (CNS) health and disease. Underlying these roles is an elaborate architecture based on frequent, extremely fine, but seemingly haphazard branches, as well as prominent features including tripartite synaptic complexes and perivascular endfeet. While broad categories of structures in astrocytes are known, the fundamental building blocks that compose them and their organizing principles have yet to be adequately defined. This is largely due to the absence of high-resolution datasets that can reveal nanoscopic features of astrocytes (i.e. 10-20nm diameter in x, y, and z) and a lack of computational approaches that can effectively interrogate astrocyte shape, organization, and nanoarchitecture. Here, we produced and analyzed multiple, high-resolution datasets of layer 2/3 mouse somatosensory cortex using focused ion beam scanning electron microscopy (8nm intervals) and computer vision approaches to provide a principled, quantitative analysis of astrocytic nanoarchitecture. A decomposition of astrocytes into fundamental parts led to the discovery of unique structural components, recurring structural motifs, and assembly of parts into an organized hierarchy. New relationships were also discerned between astrocytic processes and other CNS microanatomy including mitochondria, tripartite synapses, and cerebrovasculature. By deploying computational resources to quantitatively understand the organizing principles and nanoarchitecture of astrocytes, this study reveals the specialized anatomical adaptations of these complex cells within the CNS. One Sentence SummaryUsing high-resolution serial electron microscopy datasets and computer vision, this study provides a systematic analysis of astrocytic nanoarchitecture from multiple samples of layer 2/3 of adult mouse neocortex, and presents quantitative evidence that astrocytes organize their morphology into purposeful, classifiable assemblies with unique structural and subcellular organelle adaptations related to their physiological functions.

neuroscience↗