Determinants of Neuronal Identity - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Determinants of Neuronal Identity write by Marty Shankland. This book was released on 2012-12-02. Determinants of Neuronal Identity available in PDF, EPUB and Kindle. Determinants of Neuronal Identity brings together studies of a wide range of vertebrate and invertebrate organisms that highlight the determinants of neuronal identity. Emphasis of this book is on how neurons are generated; how their developmental identities are specified; and to what degree those identities can be subsequently modified to meet the changing needs of the organism. This book also considers various techniques used in the analysis of different organisms. This volume is comprised of 15 chapters; the first of which introduces the reader to the specification of neuronal identity in Caenorhabditis elegans. The discussion then turns to neurogenesis and segmental homology in the leech, as well as intrinsic and extrinsic factors influencing the development of Retzius neurons in the leech nervous system. Drosophila is discussed next, with particular reference to neuronal diversity in the embryonic central nervous system, cell choice and patterning in the retina, and development of the peripheral nervous system. Other chapters explore endocrine influences on the postembryonic fates of neurons during insect metamorphosis; neuron determination in the nervous system of Hydra and in the mammalian cerebral cortex; and segregation of cell lineage in the vertebrate neural crest. This book will help scientists and active researchers in synthesizing a conceptual framework for further studies of neuronal specification.
Neuronal Identity from Fate Specification to Function
Neuronal Identity from Fate Specification to Function - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Neuronal Identity from Fate Specification to Function write by Nikolaos Konstantinides. This book was released on 2023-02-02. Neuronal Identity from Fate Specification to Function available in PDF, EPUB and Kindle.
Defining Neuronal Identity Using MicroRNA-mediated Reprogramming
Defining Neuronal Identity Using MicroRNA-mediated Reprogramming - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Defining Neuronal Identity Using MicroRNA-mediated Reprogramming write by Matthew J. McCoy. This book was released on 2018. Defining Neuronal Identity Using MicroRNA-mediated Reprogramming available in PDF, EPUB and Kindle. Cell fate reprogramming is transforming our understanding of the establishment and maintenance of cellular identity. In addition, reprogramming holds great promise to model diseases affecting cell types that are prohibitively difficult to study, such as human neurons. Overexpression of the brain-enriched microRNAs (miRNAs), miR-9/9* and miR-124 (miR-9/9*-124) results in reprogramming human somatic cells into neurons and has recently been used to generate specific neuronal subtypes affected in neurodegenerative disorders. However, the mechanisms governing the ability of miR-9/9*-124 to generate alternative subtypes of neurons remained unknown. In this thesis, I report that overexpressing miR-9/9*-124 triggers reconfiguration of chromatin accessibility, DNA methylation, and mRNA expression to induce a default neuronal state. MiR-9/9*-124-induced neurons (miNs) are functionally excitable and are uncommitted towards specific subtypes yet possess open chromatin at neuronal subtype-specific loci, suggesting such identity can be imparted by additional lineage-specific transcription factors. Consistently, we show ISL1 and LHX3 selectively drive conversion to a highly homogenous population of human spinal cord motor neurons. This work shows that modular synergism between miRNAs and neuronal subtype-specific transcription factors can drive lineage-specific neuronal reprogramming, thereby providing a general platform for high-efficiency generation of distinct subtypes of human neurons. Since many neurodegenerative diseases occur after development, modeling them requires reprogramming methods capable of generating functionally mature neurons. However, few robust molecular hallmarks existed to identify such neurons, or to compare efficiencies between reprogramming methods. Recent studies demonstrated that active long genes (>100 kb from transcription start to end) are highly enriched in neurons, which provided an opportunity to identify neurons based on the expression of these long genes. We therefore worked to develop an R package, LONGO, to analyze gene expression based on gene length. We developed a systematic analysis of long gene expression (LGE) in RNA-seq or microarray data to enable validation of neuronal identity at the single-cell and population levels. By combining this conceptual advancement and statistical tool in a user-friendly and interactive software package, we intended to encourage and simplify further investigation into LGE, particularly as it applies to validating and improving neuronal differentiation and reprogramming methodologies. Using this tool, I found by single-cell RNA sequencing that microRNA-mediated neuronal reprogramming of human adult fibroblasts yields a homogenous population of mature neurons, and that LGE distinguishes mature from immature neurons. I found that LGE correlates with expression of neuronal subunits of the Swi/Snf-like (BAF) chromatin remodeling complex, such as ACTL6B/BAF53b. Finally, I found that the loss of a functional neuronal BAF complex, as well as chemical inhibition of topoisomerase I, decreases LGE and reduces spontaneous electrical activity. Together, these results provide mechanistic insights into microRNA-mediated neuronal reprogramming, and demonstrate a transcriptomic feature of functionally mature neurons.
Gene Regulatory Factors that Control the Identities of Specific Neuron Types in Caenorhabditis Elegans
Gene Regulatory Factors that Control the Identities of Specific Neuron Types in Caenorhabditis Elegans - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Gene Regulatory Factors that Control the Identities of Specific Neuron Types in Caenorhabditis Elegans write by Feifan Zhang. This book was released on 2014. Gene Regulatory Factors that Control the Identities of Specific Neuron Types in Caenorhabditis Elegans available in PDF, EPUB and Kindle. I have also studied the fate determination of several distinct neuronal cell types. I dissected the cis-regulatory information of AIA expressed genes and identified that the LIM homeodomain transcription factor TTX-3 is required for AIA fate, possibly together with another yet unknown transcription factor. TTX-3 also acts synergistically with the POU-domain transcription factor UNC-86 as master regulators for NSM. TTX-3 may also act as the terminal selector for ASK. This work provides extra evidence for the terminal selector concept and further demonstrates that individual neurons use unique and combinatorial codes of transcription factors to achieve their terminal identities, and that the same regulatory factor can be reused as a terminal selector in distinct cell types through cooperation with different cofactors.
Transcriptional and Network Regulators of Neuronal Identity Specification and Synaptic Maturation
Transcriptional and Network Regulators of Neuronal Identity Specification and Synaptic Maturation - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Transcriptional and Network Regulators of Neuronal Identity Specification and Synaptic Maturation write by Jeffrey Russ. This book was released on 2014. Transcriptional and Network Regulators of Neuronal Identity Specification and Synaptic Maturation available in PDF, EPUB and Kindle. To enact its many behaviors, an organism relies on a highly diverse network of neuronal subtypes. During development, it is therefore imperative that the identity of each subtype be correctly specified and that each of these neurons then wires with precise connectivity. The process of identity specification results from a delicate interplay between intrinsic and extrinsic influences during neuronal development. Intrinsically, a critical event in neuronal development is the expression of potent transcription factors that regulate the induction of a subtype-specific neuronal identity. One capability of such factors is to prime a neuron's connectivity by controlling features such as dendritic morphology, axonal targeting, or synaptic specificity. Once incorporated into the circuitry, the neuron relies on extrinsic signals from both its pre-and postsynaptic binding partners to further refine its identity. In this dissertation, I first examine intrinsic regulation of neuronal identity by studying the cell-autonomous capabilities of the subtype-specifying transcription factor Ptfl a to transform the development of cortical pyramidal cells. Ptfl a is primarily necessary for the identity specification of interneurons in the spinal cord, cerebellum, and retina, but its sufficiency to dictate neuronal identity outside its endogenous environment has yet to be fully explored. Using in utero electroporation to misexpress Ptfl a in the developing cortex, 1 demonstrate its ability to override the pyramidal cell transcriptome, upregulating Ptfl a-dependent markers of inhibitory interneurons and inducing a peptidergic neurotransmitter status. Concurrently, misexpression of Ptfl a also transforms the stereotypical pyramidal cell morphology to a more branched, radial morphology. To next explore the extrinsic regulation of neuronal identity, I examine the ability of the developing network to impact the characteristic synaptic protein profile of a population of spinal inhibitory interneurons, called GABApre neurons. I first show that putative GABApre neurons receive descending input from the cortex, via the corticospinal tract. I then use a mouse model of perinatal stroke to investigate how developmental disruption of corticospinal tract input in turn impacts GABApre synaptic expression. I observe a specific upregulation of the hallmark GABApre marker GAD65 contralateral to the cortical injury, implying that this effect is the result of lost input from the cortex.
