Inhibition of synaptic output in neurons expressing Scer\GAL4^pum-0441-G4 abolishes aversive responses to a number of different olfactants: 10% acetic acid, 2% ethyl butyrate and 0.1% E2-hexenal.

Flies in which synaptic output of neurons expressing Scer\GAL4^pum-0441-G4 is inhibited do not show an increase in aversive turns in response to 10% acetic acid, in contrast to controls. As is seen in wild type, they do initiate turns when moving towards the aversive source, but they fail to complete the late stages of the pattern required to appropriately reorient themselves.

Inhibition of synaptic output in neurons expressing Scer\GAL4^pum-0441-G4 abolishes learned aversion to 0.1% ethyl butyrate in an olfactory conditioning assay.

Inhibition of synaptic output in neurons expressing Scer\GAL4^pum-0441-G4 has no effect on the performance index of the attractive response to 2% vinegar. The trajectories of the flies in response to the attractant appear normal, although the attractive turns are no longer enriched and the bias of turn initiation is changed compared to wild type.

Aversion to 10% acetic acid is partially restored in flies in which synaptic output of neurons expressing Scer\GAL4^pum-0441-G4 is inhibited, by co-expression of either Scer\GAL80^tsh-GAL80, Scer\GAL80^GMR13C06 or Scer\GAL80^GMR11F03.