Detecting vibrations in digital holographic multiwavelength measurements using deep learning.

Digital holographic multiwavelength sensor systems integrated in the production line on multi-axis systems such as robots or machine tools are exposed to unknown, complex vibrations that affect the measurement quality. To detect vibrations during the early steps of hologram reconstruction, we propose a deep learning approach using a deep neural network trained to predict the standard deviation of the hologram phase. The neural network achieves 96.

Astrocyte growth is driven by the Tre1/S1pr1 phospholipid-binding G protein-coupled receptor.

Astrocytes play crucial roles in regulating neural circuit function by forming a dense network of synapse-associated membrane specializations, but signaling pathways regulating astrocyte morphogenesis remain poorly defined. Here, we show the Drosophila lipid-binding G protein-coupled receptor (GPCR) Tre1 is required for astrocytes to establish their intricate morphology in vivo. The lipid phosphate phosphatases Wunen/Wunen2 also regulate astrocyte morphology and, via Tre1, mediate astrocyte-astrocyte competition for growth-promoting lipids.

Astrocytic GABA transporter controls sleep by modulating GABAergic signaling in Drosophila circadian neurons.

A precise balance between sleep and wakefulness is essential to sustain a good quality of life and optimal brain function. GABA is known to play a key and conserved role in sleep control, and GABAergic tone should, therefore, be tightly controlled in sleep circuits. Here, we examined the role of the astrocytic GABA transporter (GAT) in sleep regulation using Drosophila melanogaster.

Focal adhesion molecules regulate astrocyte morphology and glutamate transporters to suppress seizure-like behavior.

Astrocytes are important regulators of neural circuit function and behavior in the healthy and diseased nervous system. We screened for molecules in astrocytes that modulate neuronal hyperexcitability and identified multiple components of focal adhesion complexes (FAs). Depletion of astrocytic Tensin, β-integrin, Talin, focal adhesion kinase (FAK), or matrix metalloproteinase 1 (Mmp1), resulted in enhanced behavioral recovery from genetic or pharmacologically induced seizure.

Neuromodulators signal through astrocytes to alter neural circuit activity and behaviour.

Astrocytes associate with synapses throughout the brain and express receptors for neurotransmitters that can increase intracellular calcium (Ca). Astrocytic Ca signalling has been proposed to modulate neural circuit activity, but the pathways that regulate these events are poorly defined and in vivo evidence linking changes in astrocyte Ca levels to alterations in neurotransmission or behaviour is limited. Here we show that Drosophila astrocytes exhibit activity-regulated Ca signalling in vivo.

Activity-dependent regulation of astrocyte GAT levels during synaptogenesis.

Astrocytic uptake of GABA through GABA transporters (GATs) is an important mechanism regulating excitatory/inhibitory balance in the nervous system; however, mechanisms by which astrocytes regulate GAT levels are undefined. We found that at mid-pupal stages the Drosophila melanogaster CNS neuropil was devoid of astrocyte membranes and synapses. Astrocyte membranes subsequently infiltrated the neuropil coordinately with synaptogenesis, and astrocyte ablation reduced synapse numbers by half, indicating that Drosophila astrocytes are pro-synaptogenic.

Neuron-glia interactions through the Heartless FGF receptor signaling pathway mediate morphogenesis of Drosophila astrocytes.

Astrocytes are critically important for neuronal circuit assembly and function. Mammalian protoplasmic astrocytes develop a dense ramified meshwork of cellular processes to form intimate contacts with neuronal cell bodies, neurites, and synapses. This close neuron-glia morphological relationship is essential for astrocyte function, but it remains unclear how astrocytes establish their intricate morphology, organize spatial domains, and associate with neurons and synapses in vivo.

Analysis of glial cell development and function in Drosophila.

Glial cells are the most abundant cell type in our brains, yet we understand very little about their development and function. An accumulating body of work over the last decade has revealed that glia are critical regulators of nervous system development, function, and health. Based on morphological and molecular criteria, glia in Drosophila melanogaster are very similar to their mammalian counterparts, suggesting that a detailed investigation of fly glia has the potential to add greatly to our understanding of fundamental aspects of glial cell biology.

The CD59 family member Leaky/Coiled is required for the establishment of the blood-brain barrier in Drosophila.

The blood-brain barrier of Drosophila is established by the subperineurial glial cells that encase the CNS and PNS. The subperineurial glial cells are thin, highly interdigitated cells with epithelial character. The establishment of extensive septate junctions between these cells is crucial for the prevention of uncontrolled paracellular leakage of ions and solutes from the hemolymph into the nervous system.

Drosophila Neurexin IV stabilizes neuron-glia interactions at the CNS midline by binding to Wrapper.

Ensheathment of axons by glial membranes is a key feature of complex nervous systems ensuring the separation of single axons or axonal fascicles. Nevertheless, the molecules that mediate the recognition and specific adhesion of glial and axonal membranes are largely unknown. We use the Drosophila midline of the embryonic central nervous system as a model to investigate these neuron glia interactions.

Development of the peripheral glial cells in Drosophila.

In complex organisms the nervous system comprises two cell types: neurons and glial cells. Their correct interplay is of crucial importance during both the development of the nervous system and for later function of the nervous system. In recent years tools have been developed for Drosophila that enable genetic approaches to understanding glial development and differentiation.

Organization and function of the blood-brain barrier in Drosophila.

The function of a complex nervous system depends on an intricate interplay between neuronal and glial cell types. One of the many functions of glial cells is to provide an efficient insulation of the nervous system and thereby allowing a fine tuned homeostasis of ions and other small molecules. Here, we present a detailed cellular analysis of the glial cell complement constituting the blood-brain barrier in Drosophila.

Glial cell migration in the eye disc.

Any complex nervous system is made out of two major cell types, neurons and glial cells. A hallmark of glial cells is their pronounced ability to migrate. En route to their final destinations, glial cells are generally guided by neuronal signals.

Distinct functions of alpha-Spectrin and beta-Spectrin during axonal pathfinding.

Cell-shape changes during development require a precise coupling of the cytoskeleton with proteins situated in the plasma membrane. Important elements controlling the shape of cells are the Spectrin proteins that are expressed as a subcortical cytoskeletal meshwork linking specific membrane receptors with F-actin fibers. Here, we demonstrate that Drosophila karussell mutations affect beta-spectrin and lead to distinct axonal patterning defects in the embryonic CNS.

Mummy encodes an UDP-N-acetylglucosamine-dipohosphorylase and is required during Drosophila dorsal closure and nervous system development.

Throughout development cell-cell interactions are of pivotal importance. Cells bind to each other or share information via secreted signaling molecules. To a large degree, these processes are modulated by post-translational modifications of membrane proteins.

Neuron-glia interaction in the insect nervous system.

In all complex organisms, glial cells are pivotal for neuronal development and function. Insects are characterized by having only a small number of these cells, which nevertheless display a remarkable molecular diversity. An intricate relationship between neurons and glia is initially required for glial migration and during axonal patterning.

The Drosophila cell survival gene discs lost encodes a cytoplasmic Codanin-1-like protein, not a homolog of tight junction PDZ protein Patj.

The Drosophila gene discs lost (dlt) has been reported to encode a homolog of the vertebrate tight junction PDZ protein Patj, and was thought to play a role in cell polarity. Using rescue experiments and sequence analyses, we show that dlt mutations disrupt the Drosophila Codanin-1 homolog, a cytoplasmic protein, and not the PDZ protein. Mutations in human Codanin-1 are associated with congenital dyserythropoietic anemia type I (CDA I).