The Anoctamin Family Channel Subdued Mediates Thermal Nociception in Drosophila

Abstract

Background: Subdued is a calcium-activated chloride channel of the anoctamin family in Drosophila. Results: Knockout or knockdown of subdued leads to defective nociceptive responses to heat. Conclusion: The Subdued channel mediates thermal nociception. Significance: An anoctamin channel participates in thermal nociception in insects.

Small conductance Ca2+-activated K+ channels induce the firing pause periods during the activation of Drosophila nociceptive neurons

“…These results suggest that the passive Cl − transport in Class IV neurons is outward and generates depolarizing currents but not hyperpolarizing ones. In parallel, we investigated the role of one of the Ca 2+ -activated Cl − channels, Subdued ( Jang et al, 2015 ), and showed that it can contribute to membrane excitation in the neurons ( Figure 2—figure supplement 1 ). Thus, we excluded Cl − channels as candidate sources of hyperpolarizing currents.…”

“… The gating property of subdued channels is dependent on heat, voltage and Ca 2+ , and the expression in Class IV neuron is required for larval heat avoidance behavior ( Jang et al, 2015 ). Considering the results of the Cl − ion direction ( Figure 2B–C ), the possibility of subdued channels contributing to inhibitory currents is low, although an effect of the Subdued channels on neuronal activity cannot be completely excluded.…”

Impairment of proprioceptive movement and mechanical nociception in Drosophila melanogaster larvae lacking Ppk30, a Drosophila member of the Degenerin/Epithelial Sodium Channel family

“…Larval thermal nociception assays were performed as previously described . Briefly, third instar larvae were placed on 2% agarose medium in 55 × 12‐mm plastic Petri dishes, and their abdominal segments were touched with a soldering iron with a 0.6‐mm‐wide chisel; its temperature was measured with an electronic thermometer.…”

“…Touch sensation was performed as described . Briefly, the mouth parts of third larvae were touched gently with a fine brush (n = 15, 3 times).…”

“…Touch sensation was performed as described. 1,26 Briefly, the mouth parts of third larvae were touched gently with a fine brush (n = 15, 3 times). Kernan scores were defined as follows: 0 = no response to touch, 1 = a response of pausing mouth-hook movement, 2 = responding by withdrawing or turning away from the touch, 3 = a single reverse peristaltic wave away from the touch, and 4 = multiple peristaltic waves away from the touch.…”