Project description:Development and plasticity in the nervous system are regulated by specific patterns of neural impulse activity. Patterned activity orchestrates spatial and temporal changes in the expression of networks of genes. These gene regulatory networks underlie the long-term changes in cell specification, growth of synaptic connections, and frequency adaptation that occur throughout neonatal and postnatal life. We show that the temporal nature of action potentials and downstream signaling differentially regulate the expression of hundreds of diverse neuronal genes through distinct gene regulatory networks. Analysis of upstream regulatory regions showed enrichment in transcription factor binding sites for NF-Kappa that was action potential firing pattern specific. Our new findings demonstrate spike-frequency decoding by action potentials at the transcriptional level by pattern-specific activation of transcription factors and associated gene-regulatory networks that operate to adjust the modalities of sensory neurons. We analyzed the transcriptomic changes in primary cultures of embronic dorsal root ganglia (DRG) neurons subjected to four electric stimulation patterns with respect to their non-stimulated counterparts. We have adopted the multiple yellow strategy in which differently fluorescent labeled biological replicas are co-hybridized with each array and then similarly labeled samples from cells subjected to different conditions are compared and results averaged over the two labels.
Project description:Nociceptors play an essential role in both acute pain and chronic pain conditions. In this study, we examined the proteome of mouse dorsal root ganglia and compared NaV1.8Cre+/-; ROSA26-flox-stop-flox-DTA (Diphtheria toxin fragment A) mutant mice (NaV1.8Cre-DTA), in which NaV1.8-positive neurons (mainly nociceptors) in dorsal root ganglia (DRG) were ablated, with respective littermate wildtype controls.
Project description:Vagal afferent neurons are thought to convey primarily physiological information, whereas spinal afferents transmit noxious signals from the viscera to the central nervous system. In order to elucidate molecular identities for these different properties, we compared gene expression profiles of neurons located in nodose ganglia (NG) and dorsal root ganglia (DRG) in mice. Intraperitoneal administration of Alexa Fluor-488 conjugated Cholera toxin B allowed identification of neurons projecting to the viscera. Fluorescent neurons in DRG (from T10 to T13) and NG were isolated using laser capture microdissection. Gene expression profiles of visceral afferent neurons, obtained by microarray hybridization, were analysed using multivariate spectral map analysis, SAM algorithm (Significance Analysis of Microarray data) and fold-difference filtering. A total of 1996 genes were found to be differentially expressed in DRG versus NG, including 41 G-protein coupled receptors and 60 ion channels. Expression profiles obtained on laser-captured neurons were contrasted to those obtained on whole ganglia demonstrating striking differences and the need for microdissection when studying visceral sensory neurons because of dilution of the signal by somatic sensory neurons. Furthermore, a detailed catalogue of all adrenergic and cholinergic, GABA, glutamate, serotonin and dopamine receptors, voltage-gated potassium, sodium and calcium channels and transient receptor potential cation channels present in visceral afferents is provided. Our genome-wide expression profiling data provide novel insight into molecular signatures that underlie both functional differences and similarities between NG and DRG visceral sensory neurons. Moreover, these findings will offer novel insight into mode of action of pharmacologic agents modulating visceral sensation. Experiment Overall Design: Three separate experiments were performed. First, 5 whole dorsal root ganglia were compared to 7 whole nodose ganglia. Second, Laser captured visceral neurons derived from 5 dorsal root ganglia and 5 nodose ganglia were compared on MG-U74Av2. Third, Laser captured visceral neurons derived from 9 dorsal root ganglia and 11 nodose ganglia were compared on Mouse430_2.
Project description:The goal of this study was to analyze global gene expression in specific populations of nociceptor sensory neurons, the neurons that detect damaging/noxious stimuli. The dorsal root ganglia (DRG), trigeminal ganglia, and nodose ganglia are anatomically distinct peripheral sensory ganglia that contain nociceptors which innervate skin, gut, lungs, and other distinct organ tissues. We used flow cytometry to purify nociceptors from these ganglia and profiled their global gene expression signatures to compare gene expression between these different anatomically distinct nociceptors. Nav1.8-Cre were bred with Rosa26-TdTomato to generate Nav1.8-Cre/R26-TdTomato reporter progeny, where all peripheral nociceptor neurons are genetically marked with red fluroescence due to specific expression of the TTX- resistant sodium channel Nav1.8. Lumbar region dorsal root ganglia (DRG), trigeminal ganglia, and nodose ganglia were dissected from mice (3 mice were pooled/sample). Highly red fluorescent neurons were Facs purified, RNA extracted, and processed for microarray analysis.
Project description:Here we studied the NOX2 dependent redox-proteome in dorsal root ganglia in mice. The overall goal was to assess the degree of NOX2-dependent changes in oxidised proteins following exposure to enriched enviroment and sciatic nerve axotomy in dorsal root ganglia.
Project description:We report the effects of vitamin E deficiency using the Ttpa-null mouse model on transcriptome profiles of dorsal root ganglia neurons
Project description:Aim: Dorsal root ganglion neuron-derived immortal cell lines including ND7/23 and F-11 cells have been used extensively as in vitro model systems of native peripheral sensory neurons. However, while it is clear that some sensory neuron-specific receptors and ion channels are present in these cell lines, a systematic comparison of the molecular targets expressed by these cell lines with intact peripheral neurons is lacking. Methods: we examined the expression of RNA transcripts in the human neuroblastoma-derived cell line, SH-SY5Y, and two dorsal root ganglion hybridoma cell lines, F-11 and ND7/23, using Illumina next-generation sequencing. Results: The expression profile of these three cell lines did not resemble any specific dorsal root ganglion neuron subclass. The cell lines lacked many markers for nociceptive sensory neurons, such as the transient receptor potential V1 gene, but expressed markers for both myelinated and unmyelinated neurons. Conclusion: This paper provides insights into the receptor repertoire expressed in common dorsal root ganglion neuron-derived cell lines, and illustrates the limits and potentials of these cell lines as tools for neuropharmacological exploration.