scholarly journals Mathematical models of neuronal growth

2022 ◽  
Author(s):  
Hadrien Oliveri ◽  
Alain Goriely
Keyword(s):  
Mathematical Models ◽  
Neural Development ◽  
Neurite Growth ◽  
Cellular Transport ◽  
Chemical Signaling ◽  
Neuron Development ◽  
Growth Guidance ◽  
Underlying Mechanisms ◽  
Correct Path ◽  
Biophysical Effects

AbstractThe establishment of a functioning neuronal network is a crucial step in neural development. During this process, neurons extend neurites—axons and dendrites—to meet other neurons and interconnect. Therefore, these neurites need to migrate, grow, branch and find the correct path to their target by processing sensory cues from their environment. These processes rely on many coupled biophysical effects including elasticity, viscosity, growth, active forces, chemical signaling, adhesion and cellular transport. Mathematical models offer a direct way to test hypotheses and understand the underlying mechanisms responsible for neuron development. Here, we critically review the main models of neurite growth and morphogenesis from a mathematical viewpoint. We present different models for growth, guidance and morphogenesis, with a particular emphasis on mechanics and mechanisms, and on simple mathematical models that can be partially treated analytically.

scholarly journals Parameter estimation in mathematical models of viral infections using R

2017 ◽  
Author(s):  
Van Kinh Nguyen ◽  
Esteban A. Hernandez-Vargas
Keyword(s):  
Mathematical Modeling ◽  
Parameter Estimation ◽  
Mathematical Models ◽  
Viral Infections ◽  
Free Software ◽  
Virus Dynamics ◽  
Biological Applications ◽  
Simulation Results ◽  
Underlying Mechanisms ◽  
Mathematical Relations

AbstractIn recent years, mathematical modeling approaches have played a central role to understand and to quantify mechanisms in different viral infectious diseases. In this approach, biological-based hypotheses are expressed via mathematical relations and then tested based on empirical data. The simulation results can be used to either identify underlying mechanisms, provide predictions on infection outcomes, or evaluate the efficacy of a treatment.Conducting parameter estimation for mathematical models is not an easy task. Here we detail an approach to conduct parameter estimation and to evaluate the results using the free software R. The method is applicable to influenza virus dynamics at different complexity levels, widening experimentalists capabilities in understanding their data. The parameter estimation approach presented here can be also applied to other viral infections or biological applications.

scholarly journals Microglia in the developing retina

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Fenge Li ◽  
Danye Jiang ◽  
Melanie A. Samuel
Keyword(s):  
Molecular Mechanisms ◽  
Neuron Development ◽  
Laminar Organization ◽  
Retina Development ◽  
Retinal Microglia ◽  
Mammalian Retina ◽  
Underlying Mechanisms ◽  
And Function ◽  
Neuron Function ◽  
The Brain

AbstractMicroglia are increasingly shown to be key players in neuron development and synapse connectivity. However, the underlying mechanisms by which microglia regulate neuron function remain poorly understood in part because such analysis is challenging in the brain where neurons and synapses are intermingled and connectivity is only beginning to be mapped. Here, we discuss the features and function of microglia in the ordered mammalian retina where the laminar organization of neurons and synapses facilitates such molecular studies. We discuss microglia origins and consider the evidence for molecularly distinct microglia subpopulations and their potential for differential roles with a particular focus on the early stages of retina development. We then review the models and methods used for the study of these cells and discuss emerging data that link retina microglia to the genesis and survival of particular retina cell subtypes. We also highlight potential roles for microglia in shaping the development and organization of the vasculature and discuss cellular and molecular mechanisms involved in this process. Such insights may help resolve the mechanisms by which retinal microglia impact visual function and help guide studies of related features in brain development and disease.

scholarly journals Modelling Animal Interactive Rhythms in Communication

2019 ◽  
Vol 15 ◽  
pp. 117693431882355
Author(s):  
Andrea Ravignani ◽  
Koen de Reus
Keyword(s):  
Mathematical Models ◽  
Computational Models ◽  
Animal Communication ◽  
Animal Experiments ◽  
Simulated Data ◽  
Empirical Literature ◽  
Ecological Niches ◽  
Temporal Properties ◽  
Before And After ◽  
Underlying Mechanisms

Time is one crucial dimension conveying information in animal communication. Evolution has shaped animals’ nervous systems to produce signals with temporal properties fitting their socio-ecological niches. Many quantitative models of mechanisms underlying rhythmic behaviour exist, spanning insects, crustaceans, birds, amphibians, and mammals. However, these computational and mathematical models are often presented in isolation. Here, we provide an overview of the main mathematical models employed in the study of animal rhythmic communication among conspecifics. After presenting basic definitions and mathematical formalisms, we discuss each individual model. These computational models are then compared using simulated data to uncover similarities and key differences in the underlying mechanisms found across species. Our review of the empirical literature is admittedly limited. We stress the need of using comparative computer simulations – both before and after animal experiments – to better understand animal timing in interaction. We hope this article will serve as a potential first step towards a common computational framework to describe temporal interactions in animals, including humans.

CNS Myelin: Does a Stabilizing Role in Neurodevelopment Result in Inhibition of Neuronal Repair after Adult Injury?

1998 ◽  
Vol 4 (4) ◽  
pp. 273-284 ◽  
Author(s):  
H. S. Keirstead ◽  
John D. Steeves
Keyword(s):  
Neural Development ◽  
Neurite Growth ◽  
In Vivo Studies ◽  
Inhibitory Effects ◽  
Axonal Plasticity ◽  
Collateral Sprouting ◽  
Axonal Connections

The inhibitory properties of mature oligodendrocytes and CNS myelin for neurite outgrowth were clearly documented more than a decade ago in studies involving co-cultures of dissociated glial cells and neurons. Since then, in vitro and in vivo studies have begun to characterize some of the CNS myelin-associated inhibitors of neurite growth. Furthermore, experimental techniques for neutralizing or suppressing these inhibitory effects have been developed. The results of several experiments, involving the suppression of myelination in the developing or adult CNS, suggest that the relatively late appearance of CNS myelin during neural development may serve to stabilize and restrict axonal outgrowth (e.g., collateral sprouting) after appropriate axonal connections have been established. This suggested developmental role of myelin may consolidate and limit the degree of axonal plasticity within the adult CNS; consequently, however, it might also limit axonal regeneration after injury.

scholarly journals Untargeted Metabolomics Insights into Newborns with Congenital Zika Infection

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 468
Author(s):  
Estéfane da C. Nunes ◽  
Ana M. B. de Filippis ◽  
Taiane do E. S. Pereira ◽  
Nieli R. da C. Faria ◽  
Álvaro Salgado ◽  
...  
Keyword(s):  
Neural Development ◽  
Cellular Metabolism ◽  
Essential Amino Acids ◽  
Untargeted Metabolomics ◽  
Gas Chromatography Mass Spectrometry ◽  
Serum Samples ◽  
Clinical Complications ◽  
Congenital Zika Syndrome ◽  
Emerging Virus ◽  
Underlying Mechanisms

Zika virus (ZIKV), an emerging virus belonging to the Flaviviridae family, causes severe neurological clinical complications and has been associated with Guillain-Barré syndrome, fetal abnormalities known collectively as congenital Zika syndrome, and microcephaly. Studies have shown that ZIKV infection can alter cellular metabolism, directly affecting neural development. Brain growth requires controlled cellular metabolism, which is essential for cell proliferation and maturation. However, little is known regarding the metabolic profile of ZIKV-infected newborns and possible associations related to microcephaly. Furthering the understanding surrounding underlying mechanisms is essential to developing personalized treatments for affected individuals. Thus, metabolomics, the study of the metabolites produced by or modified in an organism, constitutes a valuable approach in the study of complex diseases. Here, 26 serum samples from ZIKV-positive newborns with or without microcephaly, as well as controls, were analyzed using an untargeted metabolomics approach involving gas chromatography–mass spectrometry (GC-MS). Significant alterations in essential and non-essential amino acids, as well as carbohydrates (including aldohexoses, such as glucose or mannose) and their derivatives (urea and pyruvic acid), were observed in the metabolic profiles analyzed. Our results provide insight into relevant metabolic processes in patients with ZIKV and microcephaly.

scholarly journals Research priorities for neuroimmunology: identifying the key research questions to be addressed by 2030

2021 ◽  
Vol 6 ◽  
pp. 194
Author(s):  
Georgina MacKenzie ◽  
Sumithra Subramaniam ◽  
Lindsey J Caldwell ◽  
Denise Fitzgerald ◽  
Neil A Harrison ◽  
...  
Keyword(s):  
Neural Development ◽  
Positive Impact ◽  
Research Priorities ◽  
Future Research ◽  
Optimal Timing ◽  
Significant Progress ◽  
Medium Term ◽  
Research Teams ◽  
Research Questions ◽  
Underlying Mechanisms

Neuroimmunology in the broadest sense is the study of interactions between the nervous and the immune systems. These interactions play important roles in health from supporting neural development, homeostasis and plasticity to modifying behaviour. Neuroimmunology is increasingly recognised as a field with the potential to deliver a significant positive impact on human health and treatment for neurological and psychiatric disorders. Yet, translation to the clinic is hindered by fundamental knowledge gaps on the underlying mechanisms of action or the optimal timing of an intervention, and a lack of appropriate tools to visualise and modulate both systems. Here we propose ten key disease-agnostic research questions that, if addressed, could lead to significant progress within neuroimmunology in the short to medium term. We also discuss four cross-cutting themes to be considered when addressing each question: i) bi-directionality of neuroimmune interactions; ii) the biological context in which the questions are addressed (e.g. health vs disease vs across the lifespan); iii) tools and technologies required to fully answer the questions; and iv) translation into the clinic. We acknowledge that these ten questions cannot represent the full breadth of gaps in our understanding; rather they focus on areas which, if addressed, may have the most broad and immediate impacts. By defining these neuroimmunology priorities, we hope to unite existing and future research teams, who can make meaningful progress through a collaborative and cross-disciplinary effort.

scholarly journals Temporal evolution of single-cell transcriptomes of Drosophila olfactory projection neurons

2020 ◽  
Author(s):  
Qijing Xie ◽  
Maria Brbic ◽  
Felix Horns ◽  
Sai Saroja Kolluru ◽  
Bob Jones ◽  
...  
Keyword(s):  
Single Cell ◽  
Neural Development ◽  
Developmental Stages ◽  
Pupal Stage ◽  
Neurite Growth ◽  
Projection Neurons ◽  
Biological Processes ◽  
Functional Changes ◽  
Neuronal Types ◽  
Early Developmental

AbstractNeurons undergo substantial morphological and functional changes during development to form precise synaptic connections and acquire specific physiological features. What are the underlying transcriptomic bases? Here, we obtained the single-cell transcriptomes of Drosophila olfactory projection neurons (PNs) at four developmental stages. We decoded the identity of 21 transcriptomic clusters corresponding to 20 PN types and developed methods to match transcriptomic clusters representing the same PN type across development. We discovered that PN transcriptomes reflect unique biological processes unfolding at each stage—neurite growth and pruning during metamorphosis at an early pupal stage; peaked transcriptomic diversity during olfactory circuit assembly at mid-pupal stages; and neuronal signaling in adults. At early developmental stages, PN types with adjacent birth order share similar transcriptomes. Together, our work reveals principles of cellular diversity during brain development and provides a resource for future studies of neural development in PNs and other neuronal types.

scholarly journals Lactate transport facilitates neurite outgrowth

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Kun Chen ◽  
Peng Cheng ◽  
Huan Wang ◽  
Shutao Gao ◽  
Xiao Li ◽  
...  
Keyword(s):  
Neurite Outgrowth ◽  
Neural Development ◽  
Glycogen Synthase ◽  
Critical Role ◽  
Lactate Production ◽  
Growth Failure ◽  
Neurite Growth ◽  
Monocarboxylate Transporter ◽  
Lactate Shuttle ◽  
The Central Nervous System

How glia affect neurite outgrowth during neural development has not been well elucidated. In the present study, we found that disruption of lactate production using 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) and isofagomine significantly interfered with neurite outgrowth and that exogenous application of L-lactate rescued neurite growth failure. Monocarboxylate transporter-2-knockout, which blocked the lactate shuttle in neurons, showed a remarkable decrease in the length of axons and dendrites. We further demonstrated that Akt activity was decreased while glycogen synthase kinase 3β (GSK3β) activity was increased after astrocytic glycogen phosphorylase blockade. Additionally, GSK3βSer9 mutation reversed neurite growth failure caused by DAB and isofagomine. Our results suggested that lactate transportation played a critical role in neural development and disruption of the lactate shuttle in quiescent condition also affected neurite outgrowth in the central nervous system.

scholarly journals Common and unique strategies of male killing evolved in two distinct Drosophila symbionts

2018 ◽  
Vol 285 (1875) ◽  
pp. 20172167 ◽  
Author(s):  
Toshiyuki Harumoto ◽  
Takema Fukatsu ◽  
Bruno Lemaitre
Keyword(s):  
Dna Damage ◽  
Neural Development ◽  
Bacterial Species ◽  
Neural Tissue ◽  
Symbiotic Bacteria ◽  
Male Killing ◽  
Potential Applications ◽  
Fundamental Biology ◽  
Underlying Mechanisms ◽  
Common Target

Male killing is a selfish reproductive manipulation caused by symbiotic bacteria, where male offspring of infected hosts are selectively killed. The underlying mechanisms and the process of their evolution are of great interest not only in terms of fundamental biology, but also their potential applications. The two bacterial Drosophila symbionts, Wolbachia and Spiroplasma , have independently evolved male-killing ability. This raises the question whether the underlying mechanisms share some similarities or are specific to each bacterial species. Here, we analyse pathogenic phenotypes of D. bifasciata infected with its natural male-killing Wolbachia strain and compare them with those of D. melanogaster infected with male-killing Spiroplasma . We show that male progeny infected with the Wolbachia strain die during embryogenesis with abnormal apoptosis. Interestingly, male-killing Wolbachia infection induces DNA damage and segregation defects in the dosage-compensated chromosome in male embryos, which are reminiscent of the phenotypes caused by male-killing Spiroplasma in D. melanogaster . By contrast, host neural development seems to proceed normally unlike male-killing Spiroplasma infection. Our results demonstrate that the dosage-compensated chromosome is a common target of two distinct male killers, yet Spiroplasma uniquely evolved the ability to damage neural tissue of male embryos.

scholarly journals Plant metabolism of nematode pheromones mediates plant-nematode interactions

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Murli Manohar ◽  
Francisco Tenjo-Castano ◽  
Shiyan Chen ◽  
Ying K. Zhang ◽  
Anshu Kumari ◽  
...  
Keyword(s):  
Defense Mechanism ◽  
Parasitic Nematodes ◽  
Plant Tissues ◽  
Chemical Signaling ◽  
Plant Parasitic Nematodes ◽  
Soil Organisms ◽  
Rhizosphere Interactions ◽  
Plant Nematode ◽  
Comparative Metabolomics ◽  
Underlying Mechanisms

AbstractMicroorganisms and nematodes in the rhizosphere profoundly impact plant health, and small-molecule signaling is presumed to play a central role in plant rhizosphere interactions. However, the nature of the signals and underlying mechanisms are poorly understood. Here we show that the ascaroside ascr#18, a pheromone secreted by plant-parasitic nematodes, is metabolized by plants to generate chemical signals that repel nematodes and reduce infection. Comparative metabolomics of plant tissues and excretions revealed that ascr#18 is converted into shorter side-chained ascarosides that confer repellency. An Arabidopsis mutant defective in two peroxisomal acyl-CoA oxidases does not metabolize ascr#18 and does not repel nematodes, indicating that plants, like nematodes, employ conserved peroxisomal β-oxidation to edit ascarosides and change their message. Our results suggest that plant-editing of nematode pheromones serves as a defense mechanism that acts in parallel to conventional pattern-triggered immunity, demonstrating that plants may actively manipulate chemical signaling of soil organisms.

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