Project description:We report the effect of ablating liver-innervating cholinergic neurons in the dorsal motor nucleus of the vagus in diet-induced obese male mice
Project description:Neuronal Gene Expression We are interested in genes that determine the neuronal cellular fate and specific neurotransmitter phenotypes of cells in the nervous system. The reasons for our interest are two fold. First, identification of the genetic pathways operating in specific types of neurons could explain why they die in neurodegenerative diseases such as Alzheimer’s, Parkinson’s and amyotrophic lateral sclerosis. All of these disorders have in common the property that only certain types of neurotransmitter specific neurons degenerate. Secondly, neuronal cell replacement therapies using differentiated stem cell progeny hold the potential to reverse the devastating consequences of neurodegenerative diseases. The genetic personality of specific kinds of neurons must first be defined in order to use proper cells for neuronal replacement and this information will be essential in directing stem cell differentiation into proper developmental pathways. Our current approach to the problems of specification and neurotransmitter phenotype is to create transgenic animals where different neurotransmitter phenotypes are labeled with a fluorescent reporter gene. Labeled neurons are then isolated using Fluorescence Activated Cell Sorting. The purified populations of neurons are analyzed for their whole genome expression patterns using DNA microarray technology. We have successfully applied this approach using Drosophila cholinergic neurons and are now extending our observations to other classes of neurons that use GABA or glutamate as neurotransmitters. Cholinergic neurons express unique sets of ion channels, receptors and other types of genes. We also see unique sets of transcriptional regulatory proteins, and these may be important in the developmental pathways that result in the production of cholinergic neurons. This SuperSeries is composed of the SubSeries listed below.
Project description:Human pluripotent stem cells are a promising source of diverse cells for developmental studies, cell transplantation, disease modeling, and drug testing. However, their widespread use even for intensely studied cell types like spinal motor neurons, is hindered by the long duration and low yields of existing protocols for in vitro differentiation and by the molecular heterogeneity of the populations generated. We report a combination of small molecules that induce up to 50% motor neurons within 3 weeks from human pluripotent stem cells with defined subtype identities that are relevant to neurodegenerative diseases. Despite their accelerated differentiation, motor neurons expressed combinations of HB9, ISL1 and column-specific markers that mirror those observed in vivo in human fetal spinal cord. They also exhibited spontaneous and induced activity, and projected axons towards muscles when grafted into developing chick spinal cord. Strikingly, this novel protocol preferentially generates motor neurons expressing markers of limb-innervating lateral motor column motor neurons (FOXP1+/LHX3-). Access to high-yield cultures of human limb-innervating motor neuron subtypes will facilitate in-depth study of motor neuron subtype-specific properties, disease modeling, and development of large-scale cell-based screening assays. We analyze 3 samples including 2 positive samples and 1 negative sample. Descriptions are as follow: a) Positive Sample 1: SHH-derived, day 21 GFP-high FACS purified motor neurons.b) Positive Sample 2: S+P-derived, day 21 GFP-high FACS purified motor neurons. c) Negative: S+P condition, day 21 no GFP FACS purified motor neurons
Project description:We have generated CRISPR edited versions of hESC line MShef11 to produce MFN2 R94Q/+ and MFN2 R94Q/R94Q lines as a model for Charcot Marie Tooth Disease (CMT) 2A. This were differentiated to limb innervating motor neurons, the predominantly affected cell time in CMT2A and RNA was examined to investigate differences in cell lines.
Project description:Human pluripotent stem cells are a promising source of diverse cells for developmental studies, cell transplantation, disease modeling, and drug testing. However, their widespread use even for intensely studied cell types like spinal motor neurons, is hindered by the long duration and low yields of existing protocols for in vitro differentiation and by the molecular heterogeneity of the populations generated. We report a combination of small molecules that induce up to 50% motor neurons within 3 weeks from human pluripotent stem cells with defined subtype identities that are relevant to neurodegenerative diseases. Despite their accelerated differentiation, motor neurons expressed combinations of HB9, ISL1 and column-specific markers that mirror those observed in vivo in human fetal spinal cord. They also exhibited spontaneous and induced activity, and projected axons towards muscles when grafted into developing chick spinal cord. Strikingly, this novel protocol preferentially generates motor neurons expressing markers of limb-innervating lateral motor column motor neurons (FOXP1+/LHX3-). Access to high-yield cultures of human limb-innervating motor neuron subtypes will facilitate in-depth study of motor neuron subtype-specific properties, disease modeling, and development of large-scale cell-based screening assays.
Project description:Toothache is a common painful consequence of damage to the teeth, particularly when coupled to infection. Clinical restoration of tooth integrity, sometimes involving physical and chemical sterilization of the tooth with nerve fiber ablation (i.e., endodontic therapy), generally alleviates pain and allows long-lasting dental function. These observations raise questions regarding the biological role of tooth-innervating fibers. Here, we determined the transcriptomic diversity of the sensory neurons that can be retrogradely labeled from mouse molar teeth. Our results demonstrate that individual molars are each targeted by a dedicated population of about 50 specialized trigeminal neurons. Transcriptomic profiling identifies the majority of these as expressing markers of fast-conducting neurons, with about two-thirds containing nociceptive markers. Our data provide a new view of dental innervation, extending previous reports that used candidate gene approaches. Importantly, almost all retrogradely labeled neurons, including nociceptors, express the recently characterized mechanosensor Piezo2, an ion channel that endows cells with sensitivity to gentle touch. Intriguingly, about a quarter of the labeled neurons do not appear to be nociceptors, perhaps insinuating a role for them in discriminative touch. We hypothesize that dental neurons are capable of providing mechanosensitive information to drive rapid behavioral responses and protect teeth from damage. Damage to the teeth and exposure of the large population of molar nociceptors may trigger prolonged or abnormal activation driving toothache. Future studies examining the responses of these transcriptomically defined classes of neurons will help define their significance in oral sensation.
Project description:The discovery of genetic variants in the CHRNA5-CHRNA3-CHRNB4 gene cluster associated with heavy smoking and higher relapse risk has led to the identification of the midbrain habenula- interpeduncular axis as a critical relay circuit in the control of nicotine addiction Here we profile the cholinergic neurons of the medial habenula and identify the unique transcirptional features of this population of neurons.