Pain requires input from nociceptors which are specialised peripheral sensory neurons in dorsal root ganglia (DRG). To explore the nociceptor-specific mRNA profiles, we used microarray analysis to examine the altered repertoire of genes expressed in DRG from mice depleted of Nav1.8-expressing neurons which are mainly nociceptors. To generate the animal, a Nav1.8 knock-in Cre-expressing mouse (Nav1.8-Cre) was used to excise a floxed stop upstream of globally expressed diphtheria toxin A-subunit gene (ROSA26-eGFP-DTA). By crossing heterozygous Cre mice with homozygous toxin-expressing floxed mice, experimental toxin-expressing (DTA) mice, in which DTA expressing nociceptors had been deleted, were generated. 6 DTA mice and 6 litter mate controls were used for microarray analysis. 3 Affymetrix Mouse Genome 430 2.0 Array chips were employed for analysis of the gene transcripts of each conditions.
INSTRUMENT(S): 418 [Affymetrix]
ORGANISM(S): Mus musculus
SUBMITTER: Jing Zhao
Science (New York, N.Y.) 20080801 5889
Peripheral pain pathways are activated by a range of stimuli. We used diphtheria toxin to kill all mouse postmitotic sensory neurons expressing the sodium channel Nav1.8. Mice showed normal motor activity and low-threshold mechanical and acute noxious heat responses but did not respond to noxious mechanical pressure or cold. They also showed a loss of enhanced pain responses and spontaneous pain behavior upon treatment with inflammatory insults. In contrast, nerve injury led to heightened pain s ...[more]