This research was funded by NIMAD research grant (940714) awarded to MAF.

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All authors indicate no potential conflicts of interest.

This protocol is one of the few published papers describing the test for neurite length upon treatment with test compounds. Furthermore, we describe how to use hNPCs for a neurite outgrowth assay and neurotoxicity assessment. By utilizing this neurite outgrowth assay and neurotoxicity assessment on hNPCs-derived neurons, the neurogenic potential of a category of epigenetic small-molecule compounds, HDAC inhibitors, in inducing neurite outgrowth is demonstrated22. Furthermore, in another paper pres...

Neurite growth is a process fundamental to the formation of the neuronal network and nerve regeneration1,2. Following an injury, neurite outgrowth plays a key role in regeneration of the nervous system. Neurite outgrowth is also an important element of the extracellular signaling in inducing neuronal regenerative activities to enhance the outcomes for neurodegenerative disorders and neuronal injury3,4,5,6.
By maintaining their differentiation potential in producing various neural lineages, human neural progenitor cells (hNPCs) could provide a model system for studies of central nervous system (CNS) function and development7,8,9. High translational potential and physiological relevance of hNPCs as a primary human cell model offer a considerable advantage in neurite outgrowth-related drug discovery screenings. However, the maintenance and scaling of the primary cell models for high-throughput assays could be time-consuming and labor-intensive10,11,12,13.
In addition to the application of the presented method in neurite outgrowth studies, neurotoxicity assessment is another application using the hNPC-derived neurons. There are thousands of commercial chemical compounds that are either not examined or with poorly understood neurotoxicity potential. Therefore, more reliable and effective screening experiments to assess, distinguish, and rank compounds based on their potential to elicit developmental neurotoxicity is in high demand14. The increase in prevalence and incidence of neurological disorders along with the abundance of untested compounds in the environment necessitates the development of more trustworthy and efficient experiments to identify hazardous environmental compounds that may pose neurotoxicity15.
The presented method herein can be utilized to screen for the ability of compounds to induce neurite outgrowth and neurotoxicity by taking advantage of the human neural progenitor cell-derived neurons, a cell model closely representing human biology.

<table><tbody><tr><td>4-well Glass Chamber Slides</td><td>Sigma</td><td>PEZGS0816</td><td></td></tr><tr><td>Alexa Fluor 488</td><td>Invitrogen</td><td>A-11001</td><td></td></tr><tr><td>Alexa Fluor 594</td><td>Invitrogen</td><td>R37117</td><td></td></tr><tr><td>Antibiotic-Antimycotic</td><td>Gibco</td><td>15240062</td><td></td></tr><tr><td>Anti-&amp;beta;-Tubulin III</td><td>Thermo</td><td>MA1-118X</td><td></td></tr><tr><td>B27</td><td>Thermo</td><td>17504001</td><td></td></tr><tr><td>B27 - minus vitamin A</td><td>Thermo</td><td>12587010</td><td></td></tr><tr><td>BDNF</td><td>PeproTech</td><td>450-02</td><td></td></tr><tr><td>BSA</td><td>Sigma</td><td>A8531</td><td></td></tr><tr><td>CellTiter-Glo</td><td>Promega</td><td>G7572</td><td></td></tr><tr><td>CoolCell</td><td>Corning</td><td>432000</td><td>Cell freezing containers ensuring standardized controlled-rate -1&amp;#176;C/minute cell freezing in a -80&amp;#176;C freezer</td></tr><tr><td>CryoStor CS10</td><td>StemCell Technologies</td><td>7930</td><td>Cryopreservation medium containing 10% DMSO</td></tr><tr><td>DAPI</td><td>Thermo</td><td>D1306</td><td></td></tr><tr><td>DMEM/F12</td><td>Gibco</td><td>11320033</td><td></td></tr><tr><td>DMSO</td><td>Sigma</td><td>34869-100ML</td><td></td></tr><tr><td>EGF</td><td>Gibco</td><td>PHG0311</td><td></td></tr><tr><td>FGF</td><td>Gibco</td><td>PHG6015</td><td></td></tr><tr><td>Formaldehyde</td><td>Thermo</td><td>FB002</td><td></td></tr><tr><td>GDNF</td><td>PeproTech</td><td>450-10</td><td></td></tr><tr><td>Glutamax</td><td>Gibco</td><td>35050061</td><td>L-alanyl-L-glutamine supplement</td></tr><tr><td>Goat Serum</td><td>Thermo</td><td>50062Z</td><td></td></tr><tr><td>Heparin</td><td>Calbiochem</td><td>375095</td><td></td></tr><tr><td>Laminin</td><td>Sigma</td><td>L2020-1MG</td><td></td></tr><tr><td>L-Ascorbic Acid</td><td>Sigma</td><td>A92902-25G</td><td></td></tr><tr><td>L-lysine</td><td>Sigma</td><td>L5501</td><td></td></tr><tr><td>MEM non-essential amino acids</td><td>Gibco</td><td>11140050</td><td></td></tr><tr><td>mFreSR</td><td>StemCell Technologies</td><td>5854</td><td>Serum-free cryopreservation medium designed for the cryopreservation of human embryonic and induced pluripotent stem cells</td></tr><tr><td>N2</td><td>Gibco</td><td>17502048</td><td></td></tr><tr><td>NaCl</td><td>Sigma</td><td>71376</td><td></td></tr><tr><td>Neurobasal Medium</td><td>Gibco</td><td>21103049</td><td></td></tr><tr><td>Nunc 384-Well Polystyrene White Microplates</td><td>Thermo</td><td>164610</td><td></td></tr><tr><td>PBS</td><td>Thermo</td><td>10010-049</td><td></td></tr><tr><td>Poly-L-lysine</td><td>Sigma</td><td>P5899-5MG</td><td></td></tr><tr><td>ProLong Gold Antifade Mountant</td><td>Thermo</td><td>P10144</td><td></td></tr><tr><td>Retinoic Acid</td><td>Sigma</td><td>R2625</td><td></td></tr><tr><td>Sodium Azide</td><td>Sigma</td><td>S2002</td><td></td></tr><tr><td>StemPro Accutase</td><td>Gibco</td><td>A1110501</td><td>Cell dissociation reagent containing proteolytic and collagenolytic enzymes</td></tr><tr><td>Synaptophysin</td><td>Thermo</td><td>MA5-14532</td><td></td></tr><tr><td>Tris Base</td><td>Sigma</td><td>10708976001</td><td></td></tr><tr><td>Triton X-100</td><td>Sigma</td><td>X100-100ML</td><td></td></tr></tbody></table>

a neurite outgrowth assay and neurotoxicity assessment with human neural progenitor cell-derived neurons

Neurite outgrowth assay and neurotoxicity assessment are two major studies that can be performed using the presented method herein. This protocol provides reliable analysis of neuronal morphology together with quantitative measurements of modifications on neurite length and synaptic protein localization and abundance upon treatment with small molecule compounds. In addition to the application of the presented method in neurite outgrowth studies, neurotoxicity assessment can be performed to assess, distinguish and rank commercial chemical compounds based on their potential developmental neurotoxicity effect.
Even though cell lines are nowadays widely used in compound screening assays in neuroscience, they often differ genetically and phenotypically from their tissue origin. Primary cells, on the other hand, maintain important markers and functions observed in vivo. Therefore, due to the translation potential and physiological relevance that these cells could offer neurite outgrowth assay and neurotoxicity assessment can considerably benefit from using human neural progenitor cells (hNPCs) as the primary human cell model.
The presented method herein can be utilized to screen for the ability of compounds to induce neurite outgrowth and neurotoxicity by taking advantage of the human neural progenitor cell-derived neurons, a cell model closely representing human biology.&#34;

The protocol presented in the manuscript has successfully been used in two recently published papers22,23. Figure 3 demonstrates the use of hNPCs-derived neurons in examining the effect of HDAC inhibitors as epigenetic compounds on the extension of neurites as a marker for neurite outgrowth and subsequent neurogenic ability of small molecule compounds.
Furthermore, in Figure 4...

Watch this Scientific Journal Video about A Neurite Outgrowth Assay and Neurotoxicity Assessment with Human Neural Progenitor Cell-Derived Neurons at JoVE.com

A Neurite Outgrowth Assay and Neurotoxicity Assessment with Human Neural Progenitor Cell-Derived Neurons

The presented protocol describes a method for a neurite outgrowth assay and neurotoxicity assessment of small molecule compounds.

Neurite outgrowth assay and neurotoxicity assessment are two major studies that can be performed using the presented method herein. This protocol provides ...

a-neurite-outgrowth-assay-neurotoxicity-assessment-with-human-neural

Research

JoVE Journal

Developmental Biology

7.4K Views.  Tarbiat Modares University. Het gepresenteerde protocol beschrijft neurite uitgroeitest die zeer relevant is voor de menselijke biologie en neurotoxiciteit beoordeling van een kleine molecule verbindingen. Een hoog translationeel potentieel en fysiologische relevantie van menselijke neurale voorlopercellen als het primaire menselijke celmodel bieden een aanzienlijk voordeel bij de neuriet-ontgroeigerelateerde drug discovery screening en neurotoxiciteit beoordeling. Gebruik te maken van de gepresenteerde protocol, mensel...

Video: A Neurite Outgrowth Assay and Neurotoxicity Assessment with Human Neural Progenitor Cell-Derived Neurons

Efficient Derivation of Human Neuronal Progenitors and Neurons from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system (CNS) structure and circuitry in today's healthcare industry. Cell-based therapies hold great promise to restore the lost nerve tissue and function for CNS disorders. However, cell therapies based on CNS-derived neural stem cells have encountered supply restriction and difficulty to use in the clinical setting due to their limited expansion ability in culture and failing plasticity after extensive passaging1-3. Despite some beneficial outcomes, the CNS-derived human neural stem cells (hNSCs) appear to exert their therapeutic effects primarily by their non-neuronal progenies through producing trophic and neuroprotective molecules to rescue the endogenous cells1-3. Alternatively, pluripotent human embryonic stem cells (hESCs) proffer cures for a wide range of neurological disorders by supplying the diversity of human neuronal cell types in the developing CNS for regeneration1,4-7. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity7-10. In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic11-13. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules14 (please see a schematic in Fig. 1). Retinoic acid (RA) does not induce neuronal differentiation of undifferentiated hESCs maintained on feeders1, 14. And unlike mouse ESCs, treating hESC-differentiated embryoid bodies (EBs) only slightly increases the low yield of neurons1, 14, 15. However, after screening a variety of small molecules and growth factors, we found that such defined conditions rendered retinoic acid (RA) sufficient to induce the specification of neuroectoderm direct from pluripotent hESCs that further progressed to neuroblasts that generated human neuronal progenitors and neurons in the developing CNS with high efficiency (Fig. 2). We defined conditions for induction of neuroblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human neuronal cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of neuroblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human neuronal progenitors and neuronal cell types in the developing CNS for neural repair.

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system ...

Neuroscience

The Neuroblast Assay: An Assay for the Generation and Enrichment of Neuronal Progenitor Cells from Differentiating Neural Stem Cell Progeny Using Flow Cytometry

Neural stem cells (NSCs) can be isolated and expanded in large-scale, using the neurosphere assay and differentiated into the three major cell types of the central nervous system (CNS); namely, astrocytes, oligodendrocytes and neurons. These characteristics make neural stem and progenitor cells an invaluable renewable source of cells for in vitro studies such as drug screening, neurotoxicology and electrophysiology and also for cell replacement therapy in many neurological diseases. In practice, however, heterogeneity of NSC progeny, low production of neurons and oligodendrocytes, and predominance of astrocytes following differentiation limit their clinical applications. Here, we describe a novel methodology for the generation and subsequent purification of immature neurons from murine NSC progeny using fluorescence activated cell sorting (FACS) technology. Using this methodology, a highly enriched neuronal progenitor cell population can be achieved without any noticeable astrocyte and bona fide NSC contamination. The procedure includes differentiation of NSC progeny isolated and expanded from E14 mouse ganglionic eminences using the neurosphere assay, followed by isolation and enrichment of immature neuronal cells based on their physical (size and internal complexity) and fluorescent properties using flow cytometry technology. Overall, it takes 5-7 days to generate neurospheres and 6-8 days to differentiate NSC progeny and isolate highly purified immature neuronal cells.

This video protocol demonstrates a novel method for the generation and subsequent purification of neuronal progenitor cells from a renewable source of neural stem cells (NSCs) based on their physical (size and internal granularity) and fluorescent properties using flow cytometry technology.

Neural stem cells (NSCs) can be isolated and expanded in large-scale, using the neurosphere assay and differentiated into the three major cell types of ...

A Neuronal and Astrocyte Co-Culture Assay for High Content Analysis of Neurotoxicity

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing measurement of multiple cellular phenotypes within a single assay. In this study, we utilized HCA to develop a novel assay for neurotoxicity. Neurotoxicity assessment represents an important part of drug safety evaluation, as well as being a significant focus of environmental protection efforts. Additionally, neurotoxicity is also a well-accepted in vitro marker of the development of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Recently, the application of HCA to neuronal screening has been reported. By labeling neuronal cells with &beta;III-tubulin, HCA assays can provide high-throughput, non-subjective, quantitative measurements of parameters such as neuronal number, neurite count and neurite length, all of which can indicate neurotoxic effects. However, the role of astrocytes remains unexplored in these models. Astrocytes have an integral role in the maintenance of central nervous system (CNS) homeostasis, and are associated with both neuroprotection and neurodegradation when they are activated in response to toxic substances or disease states. GFAP is an intermediate filament protein expressed predominantly in the astrocytes of the CNS. Astrocytic activation (gliosis) leads to the upregulation of GFAP, commonly accompanied by astrocyte proliferation and hypertrophy. This process of reactive gliosis has been proposed as an early marker of damage to the nervous system. The traditional method for GFAP quantitation is by immunoassay. This approach is limited by an inability to provide information on cellular localization, morphology and cell number. We determined that HCA could be used to overcome these limitations and to simultaneously measure multiple features associated with gliosis - changes in GFAP expression, astrocyte hypertrophy, and astrocyte proliferation - within a single assay. In co-culture studies, astrocytes have been shown to protect neurons against several types of toxic insult and to critically influence neuronal survival. Recent studies have suggested that the use of astrocytes in an in vitro neurotoxicity test system may prove more relevant to human CNS structure and function than neuronal cells alone. Accordingly, we have developed an HCA assay for co-culture of neurons and astrocytes, comprised of protocols and validated, target-specific detection reagents for profiling &beta;III-tubulin and glial fibrillary acidic protein (GFAP). This assay enables simultaneous analysis of neurotoxicity, neurite outgrowth, gliosis, neuronal and astrocytic morphology and neuronal and astrocytic development in a wide variety of cellular models, representing a novel, non-subjective, high-throughput assay for neurotoxicity assessment. The assay holds great potential for enhanced detection of neurotoxicity and improved productivity in neuroscience research and drug discovery.

This article describes a novel protocol and reagent set designed for sensitive measurement of neurotoxic effects of compounds and treatments on co-cultures of neurons and astrocytes using high content analysis. Results demonstrate that high content analysis represents an exciting novel technology for neurotoxicity assessment.

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing ...

Biology

Rapid Detection of Neurodevelopmental Phenotypes in Human Neural Precursor Cells (NPCs)

Human brain development proceeds through a series of precisely orchestrated processes, with earlier stages distinguished by proliferation, migration, and neurite outgrowth; and later stages characterized by axon/dendrite outgrowth and synapse formation. In neurodevelopmental disorders, often one or more of these processes are disrupted, leading to abnormalities in brain formation and function. With the advent of human induced pluripotent stem cell (hiPSC) technology, researchers now have an abundant supply of human cells that can be differentiated into virtually any cell type, including neurons. These cells can be used to study both normal brain development and disease pathogenesis. A number of protocols using hiPSCs to model neuropsychiatric disease use terminally differentiated neurons or use 3D culture systems termed organoids. While these methods have proven invaluable in studying human disease pathogenesis, there are some drawbacks. Differentiation of hiPSCs into neurons and generation of organoids are lengthy and costly processes that can impact the number of experiments and variables that can be assessed. In addition, while post-mitotic neurons and organoids allow the study of disease-related processes, including dendrite outgrowth and synaptogenesis, they preclude the study of earlier processes like proliferation and migration. In neurodevelopmental disorders, such as autism, abundant genetic and post-mortem evidence indicates defects in early developmental processes. Neural precursor cells (NPCs), a highly proliferative cell population, may be a suitable model in which to ask questions about ontogenetic processes and disease initiation. We now extend methodologies learned from studying development in mouse and rat cortical cultures to human NPCs. The use of NPCs allows us to investigate disease-related phenotypes and define how different variables (e.g., growth factors, drugs) impact developmental processes including proliferation, migration, and differentiation in only a few days. Ultimately, this toolset can be used in a reproducible and high-throughput manner to identify disease-specific mechanisms and phenotypes in neurodevelopmental disorders.

Rapid Detection of Neurodevelopmental Phenotypes in Human Neural Precursor Cells NPCs

Neurodevelopmental processes such as proliferation, migration, and neurite outgrowth are often perturbed in neuropsychiatric diseases. Thus, we present protocols to rapidly and reproducibly assess these neurodevelopmental processes in human iPSC-derived NPCs. These protocols also allow the assessment of the effects of relevant growth factors and therapeutics on NPC development.

Human brain development proceeds through a series of precisely orchestrated processes, with earlier stages distinguished by proliferation, migration, and ...

A cGMP-applicable Expansion Method for Aggregates of Human Neural Stem and Progenitor Cells Derived From Pluripotent Stem Cells or Fetal Brain Tissue

A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the stem cell community. Many current expansion methods are laborious and costly, and those involving complete dissociation may cause several stem and progenitor cell types to undergo differentiation or early senescence. To overcome these problems, we have developed an automated mechanical passaging method referred to as &#8220;chopping&#8221; that is simple and inexpensive. This technique avoids chemical or enzymatic dissociation into single cells and instead allows for the large-scale expansion of suspended, spheroid cultures that maintain constant cell/cell contact. The chopping method has primarily been used for fetal brain-derived neural progenitor cells or neurospheres, and has recently been published for use with neural stem cells derived from embryonic and induced pluripotent stem cells. The procedure involves seeding neurospheres onto a tissue culture Petri dish and subsequently passing a sharp, sterile blade through the cells effectively automating the tedious process of manually mechanically dissociating each sphere. Suspending cells in culture provides a favorable surface area-to-volume ratio; as over 500,000 cells can be grown within a single neurosphere of less than 0.5 mm in diameter. In one T175 flask, over 50 million cells can grow in suspension cultures compared to only 15 million in adherent cultures. Importantly, the chopping procedure has been used under current good manufacturing practice (cGMP), permitting mass quantity production of clinical-grade cell products.

This protocol describes a novel mechanical chopping method that allows the expansion of spherical neural stem and progenitor cell aggregates without dissociation to a single cell suspension.&#160; Maintaining cell/cell contact allows rapid and stable growth for over 40 passages.

A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the ...

An Enhanced Green Fluorescence Protein-based Assay for Studying Neurite Outgrowth in Primary Neurons

Neurite outgrowth is a fundamental event in the formation of the neural circuits during nervous system development. Severe neurite damage and synaptic dysfunction occur in various neurodegenerative diseases and age-related degeneration. Investigation of the mechanisms that regulate neurite outgrowth would not only shed valuable light on brain developmental processes but also on such neurological disorders. Due to the low transfection efficiency, it is currently challenging to study the effect of a specific protein on neurite outgrowth in primary mammalian neurons. Here, we describe a simple method for the investigation of neurite outgrowth by the co-transfection of primary rat cortical neurons with EGFP and a protein of interest (POI). This method allows the identification of POI transfected neurons through the EGFP signal, and thus the effect of the POI on neurite outgrowth can be determined precisely. This EGFP-based assay provides a convenient approach for the investigation of pathways regulating neurite outgrowth.

In this report, we describe a simple protocol for studying neurite outgrowth in embryonic rat cortical neurons by co-transfecting with EGFP and the protein of interest.

Neurite outgrowth is a fundamental event in the formation of the neural circuits during nervous system development. Severe neurite damage and synaptic ...

Post-differentiation Replating of Human Pluripotent Stem Cell-derived Neurons for High-content Screening of Neuritogenesis and Synapse Maturation

Neurons differentiated in two-dimensional culture from human pluripotent stem-cell-derived neural progenitor cells (NPCs) represent a powerful model system to explore disease mechanisms and carry out high content screening (HCS) to interrogate compound libraries or identify gene mutation phenotypes. However, with human cells the transition from NPC to functional, mature neuron requires several weeks. Synapses typically start to form after 3 weeks of differentiation in monolayer culture, and several neuron-specific proteins, for example the later expressing pan-neuronal marker NeuN, or the layer 5/6 cerebral cortical neuron marker CTIP2, begin to express around 4-5 weeks post-differentiation. This lengthy differentiation time can be incompatible with optimal culture conditions used for small volume, multi-well HCS platforms. Among the many challenges are the need for well-adhered, uniformly distributed cells with minimal cell clustering, and culture procedures that foster long-term viability and functional synapse maturation. One approach is to differentiate neurons in a large volume format, then replate them at a later time point in HCS-compatible multi-wells. Some main challenges when using this replating approach concern reproducibility and cell viability, due to the stressful disruption of the dendritic and axonal network. Here we demonstrate a detailed and reliable procedure for enzymatically resuspending human induced pluripotent stem cell (hiPSC)-derived neurons after their differentiation for 4-8 weeks in a large-volume format, transferring them to 384-well microtiter plates, and culturing them for a further 1-3 weeks with excellent cell survival. This replating of human neurons not only allows the study of synapse assembly and maturation within two weeks from replating, but also enables studies of neurite regeneration and growth cone characteristics. We provide examples of scalable assays for neuritogenesis and synaptogenesis using a 384-well platform.

This protocol describes a detailed procedure for resuspending and culturing human stem cell derived neurons that were previously differentiated from neural progenitors in vitro for multiple weeks. The procedure facilitates imaging-based assays of neurites, synapses, and late-expressing neuronal markers in a format compatible with light microscopy and high-content screening.

Neurons differentiated in two-dimensional culture from human pluripotent stem-cell-derived neural progenitor cells (NPCs) represent a powerful model ...

Production of Human Neurogenin 2-Inducible Neurons in a Three-Dimensional Suspension Bioreactor

The derivation of neuronal lineage cells from human induced pluripotent stem cells (hiPSCs) marked a milestone in brain research. Since their first advent, protocols have been continuously optimized and are now widely used in research and drug development. However, the very long duration of these conventional differentiation and maturation protocols and the increasing demand for high-quality hiPSCs and their neural derivatives raise the need for the adoption, optimization, and standardization of these protocols to large-scale production. This work presents a fast and efficient protocol for the differentiation of genetically modified, doxycycline-inducible neurogenin 2 (iNGN2)-expressing hiPSCs into neurons using a benchtop three-dimensional (3D) suspension bioreactor.
In brief, single-cell suspensions of iNGN2-hiPSCs were allowed to form aggregates within 24 h, and neuronal lineage commitment was induced by the addition of doxycycline. Aggregates were dissociated after 2 days of induction and cells were either cryopreserved or replated for terminal maturation. The generated iNGN2 neurons expressed classical neuronal markers early on and formed complex neuritic networks within 1 week after replating, indicating an increasing maturity of neuronal cultures. In summary, a detailed step-by-step protocol for the fast generation of hiPSC-derived neurons in a 3D environment is provided that holds great potential as a starting point for disease modeling, phenotypic high-throughput drug screenings, and large-scale toxicity testing.

This article describes a protocol for the generation of human induced pluripotent stem cell-derived neurons in a benchtop 3D suspension bioreactor.

The derivation of neuronal lineage cells from human induced pluripotent stem cells (hiPSCs) marked a milestone in brain research. Since their first ...

Advanced Live-Imaging Techniques for Accurate Neurite Outgrowth Measurement

Standardization of a Novel Semi-Automatic Software for Neurite Outgrowth Measurement

Effective live-imaging techniques are crucial to assess neuronal morphology in order to measure neurite outgrowth in real time. The proper measurement of neurite outgrowth has been a long-standing challenge over the years in the neuroscience research field. This parameter serves as a cornerstone in numerous in vitro experimental setups, ranging from dissociated cultures and organotypic cultures to cell lines. By quantifying the neurite length, it is possible to determine if a specific treatment worked or if axonal regeneration is enhanced in different experimental groups. In this study, the aim is to demonstrate the robustness and accuracy of the Incucyte Neurotrack neurite outgrowth analysis software. This semi-automatic software is available in a time-lapse microscopy system which offers several advantages over commonly used methodologies in the quantification of the neurite length in phase contrast images. The algorithm masks and quantifies several parameters in each image and returns neuronal cell metrics, including neurite length, branch points, cell-body clusters, and cell-body cluster areas. Firstly, we validated the robustness and accuracy of the software by correlating its values with those of the manual NeuronJ, a Fiji plug-in. Secondly, we used the algorithm which is able to work both on phase contrast images as well as on immunocytochemistry images. Using specific neuronal markers, we validated the feasibility of the fluorescence-based neurite outgrowth analysis on sensory neurons in vitro cultures. Additionally, this software can measure neurite length across various seeding conditions, ranging from individual cells to complex neuronal nets. In conclusion, the software provides an innovative and time-effective platform for neurite outgrowth assays, paving the way for faster and more reliable quantifications.

Author Spotlight: Unveiling the Molecular Basis of Pain Perception and Neuropathic Pain

Neurite outgrowth assays provide a quantitative value about regenerative neuronal processes. The advantage of this semi-automatic software is that it segments cell bodies and neurites separately by creating a mask and measures various parameters such as neurite length, number of branch points, cell-body cluster area, and number of cell clusters.

Effective live-imaging techniques are crucial to assess neuronal morphology in order to measure neurite outgrowth in real time. The proper measurement of ...

NPC Neurosphere Assay: An In Vitro Assay to Assess the Migratory Response of Neural Precursor Cells from the Neurosphere

Source: Williams, M. et al. <a href="https://www.jove.com/v/56628/rapid-detection-neurodevelopmental-phenotypes-human-neural-precursor">Rapid Detection of Neurodevelopmental Phenotypes in Human Neural Precursor Cells (NPCs).</a>&#160;J. Vis. Exp. (2018)
This video demonstrates the neural precursor cell neurosphere migration assay&#8212;an in vitro assay to study the migratory response of neural precursor cells from the neurosphere&#8212;via microscopic analysis.

Source: Williams, M. et al. Rapid Detection of Neurodevelopmental Phenotypes in Human Neural Precursor Cells (NPCs).&#160;J. Vis. Exp. (2018)
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A Neurite Outgrowth Assay and Neurotoxicity Assessment with Human Neural Progenitor Cell-Derived Neurons

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