ERG-recordings from trplninaE.T:Avic\GFP-EGFP-expressing mutants reveals responses to medium intensity lights, which decline to that of the dark baseline during illumination, within 5 seconds. This light response is very different to wild-type flies, which have a sustained response during illumination and the response to the first and second light pulses are virtually identical. Intensity-response relationships (V-log I curves) of trplninaE.T:Avic\GFP-EGFP-expressing mutants mutants are shifted to higher levels of light intensity by about 1 log unit as compared to wild-type flies. Responses of trplninaE.T:Avic\GFP-EGFP-expressing mutants to a second light pulse are significantly lager than in wild-type.