title: Potential role of transient receptor potential channel M5 in sensing putative pheromones in mouse olfactory sensory neurons.
abstract: Based on pharmacological studies of chemosensory transduction in transient receptor potential channel M5 (TRPM5) knockout mice it was hypothesized that this channel is involved in transduction for a subset of putative pheromones in mouse olfactory sensory neurons (OSNs). Yet, in the same study an electroolfactogram (EOG) in the mouse olfactory epithelium showed no significant difference in the responses to pheromones (and odors) between wild type and TRPM5 knockout mice. Here we show that the number of OSNs expressing TRPM5 is increased by unilateral naris occlusion. Importantly, EOG experiments show that mice lacking TRPM5 show a decreased response in the occluded epithelia to putative pheromones as opposed to wild type mice that show no change upon unilateral naris occlusion. This evidence indicates that under decreased olfactory sensory input TRPM5 plays a role in mediating putative pheromone transduction. Furthermore, we demonstrate that cyclic nucleotide gated channel A2 knockout (CNGA2-KO) mice that show substantially decreased or absent responses to odors and pheromones also have elevated levels of TRPM5 compared to wild type mice. Taken together, our evidence suggests that TRPM5 plays a role in mediating transduction for putative pheromones under conditions of reduced chemosensory input.
authors.affiliation: Department of Cell and Developmental Biology, Neuroscience Program, and Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Aurora, Colorado, United States of America.
authors.forename: Arisa
authors.initials: A
authors.lastname: Oshimoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Wakabayashi
authors.forename: Anna
authors.initials: A
authors.lastname: Garske
authors.forename: Roberto
authors.initials: R
authors.lastname: Lopez
authors.forename: Shane
authors.initials: S
authors.lastname: Rolen
authors.forename: Michael
authors.initials: M
authors.lastname: Flowers
authors.forename: Nicole
authors.initials: N
authors.lastname: Arevalo
authors.forename: Diego
authors.initials: D
authors.lastname: Restrepo
mesh_terms: D000818:Animals; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D018034:Olfactory Receptor Neurons / Q000187:drug effects* / Q000378:metabolism*; D010675:Pheromones / Q000494:pharmacology*; D012903:Smell / Q000235:genetics / Q000502:physiology*; D050053:TRPM Cation Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: C518240:Cnga2 protein, mouse; D054815:Cyclic Nucleotide-Gated Cation Channels; D010675:Pheromones; D050053:TRPM Cation Channels; C498617:Trpm5 protein, mouse