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Cold temperature detection involves the process of sensory transduction in cutaneous primary sensory nerve terminals, which converts thermal stimuli into depolarizations of the membrane. This transformation into electrical signals is followed by the subsequent propagation of action potentials in cold-sensitive afferent nerve fibers. A large array of ion channels shapes this process; however, the precise contribution of specific ion channel subtypes to cold perception and cold pain remains elusive. This review aims at giving an update on our current understanding of the role played by TRPs, leak K+ and voltage-gated Na+ and K+ channels in the transduction of cold by nociceptors and in cold-induced pain.

The purpose was to investigate acute effects of normobaric hypoxia on hand-temperature responses during and after a cold-water hand immersion test. Fifteen males performed two right-hand immersion tests in 8 degrees C water, during which they were inspiring either room air (Fio(2): 0.21; AIR), or a hypoxic gas mixture (Fio(2): 0.14; HYPO). The tests were conducted in a counterbalanced order and separated by a 1-hour interval. Throughout the 30-min cold-water immersion (CWI) and the 15-min spontaneous rewarming (RW) phases, finger-skin temperatures were measured continuously with thermocouple probes; infrared thermography was also employed during the RW phase to map all segments of the hand. During the CWI phase, the average skin temperature (Tavg) of the fingers did not differ between the conditions (AIR: 10.2 +/- 0.5 degrees C, HYPO: 10.0 +/- 0.5 degrees C; p = 0.67). However, Tavg was lower in the HYPO than the AIR RW phase (AIR: 24.5 +/- 3.4 degrees C; HYPO: 22.0 +/- 3.8 degrees C; p = 0.002); a response that was alike in all regions of the immersed hand. Accordingly, present findings suggest that acute exposure to normobaric hypoxia does not aggravate the cold-induced drop in hand temperature of normothermic males. Still, hypoxia markedly impairs the rewarming responses of the hand., QC 20140808

Background: The P2X7 receptor is a member of the P2X family of adenosine 5'-triphosphate- gated cation channels. Several recent studies have demonstrated that this receptor is involved in mechanisms related to pain and inflammation. However, unknown is whether polymorphisms of the P2RX7 gene that encodes the human P2X7 receptor influence pain sensitivity and analgesic effects of opioids. The P2RX7 gene is known to be highly polymorphic. Thus, the present study examined associations between fentanyl sensitivity and polymorphisms in the P2RX7 gene in 355 Japanese patients who underwent painful orofacial cosmetic surgery. Results: We first conducted linkage disequilibrium (LD) analyses for 55 reported single-nucleotide polymorphisms (SNPs) in the region within and around the P2RX7 gene using genomic samples from 100 patients. In our samples, 42 SNPs were polymorphic, and a total of five LD blocks with six Tag SNPs (rs2708092, rs1180012, rs1718125, rs208293, rs1718136, and rs7132846) were observed. Thus, we further analyzed associations between genotypes/haplotypes of these Tag SNPs and clinical data using a total of 355 samples. In the genotype-based association study, only the rs1718125 G > A SNP tended to be associated with higher pain scores on a visual analog scale 24 h after surgery (VAS24). The haplotype-based association study showed that subjects with homozygous haplotype No. 3 (GTAAAC; estimated frequency: 15.0%) exhibited significantly higher cold pain sensitivity and lower analgesic effects of fentanyl for acute cold pain in the cold pressor test. Conversely, subjects who carried haplotype No. 1 (ACGGAC; estimated frequency: 24.5%) tended to exhibit lower cold pain sensitivity and higher analgesic effects of fentanyl. Furthermore, subjects with homozygous haplotype No. 2 (GCGGAC; estimated frequency: 22.9%) exhibited significantly lower VAS24 scores. Conclusions: Cold pain sensitivity and analgesic effects of fentanyl were related to the SNP and haplotypes o

Background: The P2X7 receptor is a member of the P2X family of adenosine 5'-triphosphate- gated cation channels. Several recent studies have demonstrated that this receptor is involved in mechanisms related to pain and inflammation. However, unknown is whether polymorphisms of the P2RX7 gene that encodes the human P2X7 receptor influence pain sensitivity and analgesic effects of opioids. The P2RX7 gene is known to be highly polymorphic. Thus, the present study examined associations between fentanyl sensitivity and polymorphisms in the P2RX7 gene in 355 Japanese patients who underwent painful orofacial cosmetic surgery. Results: We first conducted linkage disequilibrium (LD) analyses for 55 reported single-nucleotide polymorphisms (SNPs) in the region within and around the P2RX7 gene using genomic samples from 100 patients. In our samples, 42 SNPs were polymorphic, and a total of five LD blocks with six Tag SNPs (rs2708092, rs1180012, rs1718125, rs208293, rs1718136, and rs7132846) were observed. Thus, we further analyzed associations between genotypes/haplotypes of these Tag SNPs and clinical data using a total of 355 samples. In the genotype-based association study, only the rs1718125 G > A SNP tended to be associated with higher pain scores on a visual analog scale 24 h after surgery (VAS24). The haplotype-based association study showed that subjects with homozygous haplotype No. 3 (GTAAAC; estimated frequency: 15.0%) exhibited significantly higher cold pain sensitivity and lower analgesic effects of fentanyl for acute cold pain in the cold pressor test. Conversely, subjects who carried haplotype No. 1 (ACGGAC; estimated frequency: 24.5%) tended to exhibit lower cold pain sensitivity and higher analgesic effects of fentanyl. Furthermore, subjects with homozygous haplotype No. 2 (GCGGAC; estimated frequency: 22.9%) exhibited significantly lower VAS24 scores. Conclusions: Cold pain sensitivity and analgesic effects of fentanyl were related to the SNP and haplotype

Background: The P2X7 receptor is a member of the P2X family of adenosine 5'-triphosphate- gated cation channels. Several recent studies have demonstrated that this receptor is involved in mechanisms related to pain and inflammation. However, unknown is whether polymorphisms of the P2RX7 gene that encodes the human P2X7 receptor influence pain sensitivity and analgesic effects of opioids. The P2RX7 gene is known to be highly polymorphic. Thus, the present study examined associations between fentanyl sensitivity and polymorphisms in the P2RX7 gene in 355 Japanese patients who underwent painful orofacial cosmetic surgery. Results: We first conducted linkage disequilibrium (LD) analyses for 55 reported single-nucleotide polymorphisms (SNPs) in the region within and around the P2RX7 gene using genomic samples from 100 patients. In our samples, 42 SNPs were polymorphic, and a total of five LD blocks with six Tag SNPs (rs2708092, rs1180012, rs1718125, rs208293, rs1718136, and rs7132846) were observed. Thus, we further analyzed associations between genotypes/haplotypes of these Tag SNPs and clinical data using a total of 355 samples. In the genotype-based association study, only the rs1718125 G > A SNP tended to be associated with higher pain scores on a visual analog scale 24 h after surgery (VAS24). The haplotype-based association study showed that subjects with homozygous haplotype No. 3 (GTAAAC; estimated frequency: 15.0%) exhibited significantly higher cold pain sensitivity and lower analgesic effects of fentanyl for acute cold pain in the cold pressor test. Conversely, subjects who carried haplotype No. 1 (ACGGAC; estimated frequency: 24.5%) tended to exhibit lower cold pain sensitivity and higher analgesic effects of fentanyl. Furthermore, subjects with homozygous haplotype No. 2 (GCGGAC; estimated frequency: 22.9%) exhibited significantly lower VAS24 scores. Conclusions: Cold pain sensitivity and analgesic effects of fentanyl were related to the SNP and haplotypes o

Published in: S. Prince-Embury, D. H. Saklofske (Eds.), Resilience in children, adolescents, and adults: Translating research into practice. New York, NY US: Springer Science + Business Media, 2013.

Published in: The Journal of Pain, vol. 10, no.5, 2009.

Published in: S. Prince-Embury, D. H. Saklofske (Eds.), Resilience in children, adolescents, and adults: Translating research into practice. New York, NY US: Springer Science + Business Media, 2013.

Published in: The Journal of Pain, vol. 10, no.5, 2009.