Taste neurons of the labellum, the main taste organ of Drosophila, that express either Gr5a or Gr66a. Neurons expressing Gr5a mediate sensitivity to sweet tastants, whereas bitter taste sensitivity is mediated by neurons expressing Gr66a. Inset:
Composite of the axonal projections to the brain of taste neurons expressing either Gr5a or Gr66a. Taste neurons expressing only Gr5a give a very different projection pattern in the brain compared to neurons expressing Gr66a.

Natasha Thorne in the laboratory of Hubert Amrein, MGM Department