Culture of Larval and Pupal Dendritic Arborization Neurons.

dendritic arborization (da) neurons are a powerful model for studying neuronal differentiation and sensory functions. A general experimental strength of this model is the examination of the neurons in situ in the body wall. However, for some analyses, restricted access to the neurons in situ causes difficulty; da neuron cultures circumvent this.

Filleting and Immunostaining of Larvae to Visualize Dendritic Arborization Neuron Dendrite Arbors.

Nervous system formation involves the specification of neuron identity, followed by precise circuit construction; this includes controlling the pattern and connectivity of the dendrite arbor. dendritic arborization (da) neurons are a powerful experimental model for studying dendrite arbor differentiation mechanisms. da neuron dendrite arbors elaborate in two dimensions in the body wall, making it easy to visualize them with high resolution.

Mosaic Analysis with a Repressible Cell Marker (MARCM) Clone Generation in Dendritic Arborization Neurons.

Mosaic analysis with a repressible cell marker (MARCM) is used in research to create labeled homozygous mutant clones of cells in an otherwise heterozygous fly. It allows the study of the effect of embryonically lethal genes and the determination of cell autonomy for a mutant phenotype. When used in dendritic arborization (da) neurons with a fluorescent protein targeted to the plasma membrane, MARCM allows the identification of homozygous mutant neurons and clear imaging of the dendrite arbor in both live and fixed preparations.

Use of DeTerm for Automated Dendrite Arbor Terminal Counts.

Neurons have a complex dendritic architecture that governs information flow through a circuit. Manual quantification of dendritic arbor morphometrics is time-consuming and can be inaccurate. Automated quantification systems such as DeTerm help to overcome these limitations.

Mounting of Embryos, Larvae, and Pupae for Live Dendritic Arborization Neuron Imaging.

Live imaging approaches are essential for monitoring how neurons go through a coordinated series of differentiation steps in their native mechanical and chemical environment. These imaging approaches also allow the study of dynamic subcellular processes such as cytoskeleton remodeling and the movement of organelles. dendritic arborization (da) neurons are a powerful experimental system for studying the dendrite arbor in live animals.

Study of Dendrite Differentiation Using Dendritic Arborization Neurons.

Neurons receive, process, and integrate inputs. These operations are organized by dendrite arbor morphology, and the dendritic arborization (da) neurons of the peripheral sensory nervous system are an excellent experimental model for examining the differentiation processes that build and shape the dendrite arbor. Studies in da neurons are enabled by a wealth of fly genetic tools that allow targeted neuron manipulation and labeling of the neuron's cytoskeletal or organellar components.

MTOC Organization and Competition During Neuron Differentiation.

Neurons are polarized cells with long branched axons and dendrites. Microtubule generation and organization machineries are crucial to grow and pattern these complex cellular extensions. Microtubule organizing centers (MTOCs) concentrate the molecular machinery for templating microtubules, stabilizing the nascent polymer, and organizing the resultant microtubules into higher-order structures.

The p75 Neurotrophin Receptor Is an Essential Mediator of Impairments in Hippocampal-Dependent Associative Plasticity and Memory Induced by Sleep Deprivation.

Sleep deprivation (SD) interferes with hippocampal structural and functional plasticity, formation of long-term memory and cognitive function. The molecular mechanisms underlying these effects are incompletely understood. Here, we show that SD impaired synaptic tagging and capture and behavioral tagging, two major mechanisms of associative learning and memory.

Abnormal TDP-43 function impairs activity-dependent BDNF secretion, synaptic plasticity, and cognitive behavior through altered Sortilin splicing.

Aberrant function of the RNA-binding protein TDP-43 has been causally linked to multiple neurodegenerative diseases. Due to its large number of targets, the mechanisms through which TDP-43 malfunction cause disease are unclear. Here, we report that knockdown, aggregation, or disease-associated mutation of TDP-43 all impair intracellular sorting and activity-dependent secretion of the neurotrophin brain-derived neurotrophic factor (BDNF) through altered splicing of the trafficking receptor Sortilin.

Structural basis of death domain signaling in the p75 neurotrophin receptor.

Death domains (DDs) mediate assembly of oligomeric complexes for activation of downstream signaling pathways through incompletely understood mechanisms. Here we report structures of complexes formed by the DD of p75 neurotrophin receptor (p75(NTR)) with RhoGDI, for activation of the RhoA pathway, with caspase recruitment domain (CARD) of RIP2 kinase, for activation of the NF-kB pathway, and with itself, revealing how DD dimerization controls access of intracellular effectors to the receptor. RIP2 CARD and RhoGDI bind to p75(NTR) DD at partially overlapping epitopes with over 100-fold difference in affinity, revealing the mechanism by which RIP2 recruitment displaces RhoGDI upon ligand binding.

Neuron-type-specific signaling by the p75NTR death receptor is regulated by differential proteolytic cleavage.

Signaling by the p75 neurotrophin receptor (p75(NTR), also known as NGFR) is often referred to as cell-context dependent, but neuron-type-specific signaling by p75(NTR) has not been systematically investigated. Here, we report that p75(NTR) signals very differently in hippocampal neurons (HCNs) and cerebellar granule neurons (CGNs), and we present evidence indicating that this is partly controlled by differential proteolytic cleavage. Nerve growth factor (NGF) induced caspase-3 activity and cell death in HCNs but not in CGNs, whereas it stimulated NFκB activity in CGNs but not in HCNs.

Enhanced differentiation of neural progenitor cells into neurons of the mesencephalic dopaminergic subtype on topographical patterns.

Parkinson's disease (PD) is a neurodegenerative disease attributed to the loss of midbrain dopaminergic (DA) neurons. The current lack of predictive models for this disease has been hampered by the acquirement of robust cells, posing a major barrier to drug development. Differentiation of stem cells into subtype specific cells may be guided by appropriate topographical cues but the role of topography has hitherto not been well understood.

Extending neurites sense the depth of the underlying topography during neuronal differentiation and contact guidance.

The topography of the extracellular microenvironment influences cell morphology, provides conduct guidance and directs cell differentiation. Aspect ratio and dimension of topography have been shown to affect cell behaviours, but the ability and mechanism of depth-sensing is not clearly understood. We showed that murine neural progenitor cells (mNPCs) can sense the depth of the micro-gratings.