Anoxia activated the TRP and TRPL channels in both WT and PLC null mutant (norpA^P24) as monitored by Ca²⁺ influx. Extracellular voltage change (ERG, upper traces in both 3A and 3B) and potentiometric measurements with Ca²⁺-selective microelectrode (E_Ca, lower traces in both 3A and 3B) in response to orange lights and anoxia in WT Drosophila and norpA^P24 mutant. Note that there is no response to light in the norpA^P24 mutant and the initial slow phase of the electrical response to anoxia is missing in the Ca²⁺ signals of both WT and the mutant. (From Agam et al. 2000, Copyright 2000 by the Society for Neuroscience.)