Neuronal dendrites must relay synaptic inputs over long distances, but the mechanisms by which activity-evoked intracellular signals propagate over macroscopic distances remain unclear. Here, we discovered a system of periodically arranged endoplasmic reticulum-plasma membrane (ER-PM) junctions tiling the plasma membrane of dendrites at ∼1 μm intervals, interlinked by a meshwork of ER tubules patterned in a ladder-like array. Populated with Junctophilin-linked plasma membrane voltage-gated Ca channels and ER Ca-release channels (ryanodine receptors), ER-PM junctions are hubs for ER-PM crosstalk, fine-tuning of Ca homeostasis, and local activation of the Ca/calmodulin-dependent protein kinase II.
View Article and Find Full Text PDFVision provides animals with detailed information about their surroundings, conveying diverse features such as color, form, and movement across the visual scene. Computing these parallel spatial features requires a large and diverse network of neurons, such that in animals as distant as flies and humans, visual regions comprise half the brain's volume. These visual brain regions often reveal remarkable structure-function relationships, with neurons organized along spatial maps with shapes that directly relate to their roles in visual processing.
View Article and Find Full Text PDFBackground: Neuroscience research in Drosophila is benefiting from large-scale connectomics efforts using electron microscopy (EM) to reveal all the neurons in a brain and their connections. To exploit this knowledge base, researchers relate a connectome's structure to neuronal function, often by studying individual neuron cell types. Vast libraries of fly driver lines expressing fluorescent reporter genes in sets of neurons have been created and imaged using confocal light microscopy (LM), enabling the targeting of neurons for experimentation.
View Article and Find Full Text PDFCOVID-19 had sudden and dramatic impacts on the organisation and governance of urban life. In Part 2 of this Special Issue on public health emergencies we question the extent to which the pandemic ushered in fundamentally new understandings of urban public health, noting that ideas of urban pathology and the relation of dirt, disease and danger in cities, have long informed practices of planning. Emphasising important continuities in the way pandemics are associated with minoritised and vulnerable groups, past and present, we note that public health initiatives can often exacerbate existing health divides, and actually deepen health crises.
View Article and Find Full Text PDFCOVID-19 has had unprecedented impacts on urban life on a global scale, representing the worst pandemic in living memory. In this introduction to the first of two parts of a Special Issue on urban public health emergencies, we suggest that the COVID-19 outbreak, and associated attempts to manage the pandemic, reproduced and ultimately exacerbated the social and spatial divides that striate the contemporary city. Here, we draw on evidence from the papers in Part 1 of the Special Issue to summarise the uneven urban geographies of COVID-19 evident at the inter- and intra-urban level, emphasising the particular vulnerabilities and risks borne by racialised workers who found it difficult to practise social distancing in either their home or working life.
View Article and Find Full Text PDFThe neural circuits responsible for animal behavior remain largely unknown. We summarize new methods and present the circuitry of a large fraction of the brain of the fruit fly . Improved methods include new procedures to prepare, image, align, segment, find synapses in, and proofread such large data sets.
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