||Neuronal processing of noxious thermal stimuli mediated by dendritic Ca(2+) influx in Drosophila somatosensory neurons.
Terada, Shin-Ichiro ,
Matsubara, Daisuke ,
Onodera, Koun ,
Matsuzaki, Masanori ,
Uemura, TadashiUsui, Tadao
52016-02-15 , eLife Sciences Publications Ltd.
危機回避行動を感覚ニューロンが調節するしくみを解明 -痛覚神経細胞の発火パターンが回避行動を選択している-. 京都大学プレスリリース. 2016-02-24.
Adequate responses to noxious stimuli causing tissue damages are essential for organismal survival. Class IV neurons in Drosophila larvae are polymodal nociceptors responsible for thermal, mechanical, and light sensation. Importantly, activation of Class IV provoked distinct avoidance behaviors, depending on the inputs. We found that noxious thermal stimuli, but not blue light stimulation, caused a unique pattern of Class IV, which were composed of pauses after high-frequency spike trains and a large Ca(2+) rise in the dendrite (the Ca(2+) transient). Both these responses depended on two TRPA channels and the L-type voltage-gated calcium channel (L-VGCC), showing that the thermosensation provokes Ca(2+) influx. The precipitous fluctuation of firing rate in Class IV neurons enhanced the robust heat avoidance. We hypothesize that the Ca(2+) influx can be a key signal encoding a specific modality.