The Gr5a promoter controls expression of a lexA::VP16 driver.
EcollexAVP16.Gr5a.cGa drives expression in all sweet taste receptor neurons in the labellar taste hairs, and in about 9 segmental tarsal sugar-sensing chemosensory neurons in the prothoracic leg that project to the prothoracic ganglion.
The dendrites of the EcollexAGr5a.T:HsimVP16 sugar-sensitive neurons of gustatory sensilla and the ScerGAL4E49 labelled motor neurons are in close proximity. However, GFP reconstitution across synaptic partners (GRASP) did not reveal any contacts between them.
Optogenetic activation (using Cnoc\ChR1::Csub\ChRCsChrimson.IVS.13XLexAop2.Venus with 617 nm (red) light) of Ecol\lexAVP16.Gr5a.cGa cells in adults induces proboscis extensions, compared to controls.