title: Defining the nociceptor transcriptome.
abstract: Unbiased "omics" techniques, such as next generation RNA-sequencing, can provide entirely novel insights into biological systems. However, cellular heterogeneity presents a significant barrier to analysis and interpretation of these datasets. The neurons of the dorsal root ganglia (DRG) are an important model for studies of neuronal injury, regeneration and pain. The majority of investigators utilize a dissociated preparation of whole ganglia when studying cellular and molecular function. We demonstrate that the standard methods for producing these preparations gives a 10%-neuronal mixture of cells, with the remainder of cells constituting satellite glia and other non-neuronal cell types. Using a novel application of magnetic purification, we consistently obtain over 95% pure, viable neurons from adult tissue, significantly enriched for small diameter nociceptors expressing the voltage gated ion channel Nav1.8. Using genome-wide RNA-sequencing we compare the currently used (10% neuronal) and pure (95% nociceptor) preparations and find 920 genes enriched. This gives an unprecedented insight into the molecular composition of small nociceptive neurons in the DRG, potentially altering the interpretation of previous studies performed at the tissue level, and indicating a number of novel markers of this widely-studied population of cells. We anticipate that the ease of use, affordability and speed of this technique will see it become widely adopted, delivering a greatly improved capacity to study the roles of nociceptors in health and disease.
authors.affiliation: Wolfson Centre for Age-Related Diseases, King's College London London, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Thakur
authors.affiliation: Wolfson Centre for Age-Related Diseases, King's College London London, UK.
authors.forename: Megan
authors.initials: M
authors.lastname: Crow
authors.affiliation: Wolfson Centre for Age-Related Diseases, King's College London London, UK.
authors.forename: Natalie
authors.initials: N
authors.lastname: Richards
authors.affiliation: Wolfson Centre for Age-Related Diseases, King's College London London, UK.
authors.forename: Gareth I J
authors.initials: GI
authors.lastname: Davey
authors.affiliation: Wolfson Centre for Age-Related Diseases, King's College London London, UK.
authors.forename: Emma
authors.initials: E
authors.lastname: Levine
authors.affiliation: Wolfson Centre for Age-Related Diseases, King's College London London, UK.
authors.forename: Jayne H
authors.initials: JH
authors.lastname: Kelleher
authors.affiliation: Centre of Human and Aerospace Physiological Sciences, King's College London London, UK.
authors.forename: Chibeza C
authors.initials: CC
authors.lastname: Agley
authors.affiliation: Wolfson Centre for Age-Related Diseases, King's College London London, UK.
authors.forename: Franziska
authors.initials: F
authors.lastname: Denk
authors.affiliation: Centre of Human and Aerospace Physiological Sciences, King's College London London, UK.
authors.forename: Stephen D R
authors.initials: SD
authors.lastname: Harridge
authors.affiliation: Wolfson Centre for Age-Related Diseases, King's College London London, UK.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: McMahon
keywords: RNA-sequencing; dorsal root ganglion; nociception; nociceptors; pain; peripheral nervous system; regeneration; somatosensation