Research Mentor(s): Bo Duan, Assistant professor
Research Mentor School/College/Department: Molecular, Cellular, and Developmental Biology, College of Literature, Science, and the Arts
Presentation Date: Thursday, April 22, 2021
Session: Session 6 (4pm-4:50pm)
Breakout Room: Room 7
The cation channel TRPM8 has been implicated in cold detection, yet no identification of distinct subpopulations of TRPM8-expressing sensory neurons responsible for detecting different levels of cold stimuli (noxious vs. innocuous) has been made. The current study takes advantage of Designer Receptors Exclusively Activated by Designer Drugs (DREADD), light-sensitive channelrhodopsin-2 ion channels (ChR2), thermal behavioral assays, immunostaining, and RNAscope technology to investigate the role of different subpopulations of TRPM8 sensory neurons in dorsal root ganglia of mice. First, we want to study the function of TRPM8 sensory neurons in vivo by expressing an inhibitory Gi DREADD selectively in TRPM8 sensory neurons in the dorsal root ganglia (DRG) of mice. Upon injection of the DREADD agonist clozapine-N-oxide (CNO), the DREADD-expressing TRPM8 sensory neurons could be selectively inhibited to infer neuronal function following cold-plate behavioral assays. Sensory neurons in the DRG can be broadly divided into three groups based on cell body diameter: small, medium and large. From our RNAscope results, “small” TRPM8 neurons expressed significantly higher levels of the trpm8 gene than “medium to large” TRPM8 neurons, potentially providing a basis for differentiation between the two subpopulations. Thermal-related behavioral experiments are still ongoing. We hypothesize that the two subpopulations of TRPM8 sensory neurons serve distinct functions in sensing cold stimuli of different intensities.
Authors: Bo Duan, Chia Chun Hor, Matthew Eitzman
Research Method: Laboratory Research with Animals