part of continuous with synaptic neuropil subdomain subregion AA of AMMC zone A subregion AV of AMMC zone A FBbt:00047896 bundle A ventral Subregion of AMMC zone A. This contains the ventral subbundle of Johnston organ neuron axons that forms from bundle AA (subregion AA) and enters the gnathal ganglion. It is rich with the presynapses of Johnston organ neurons. antennal mechanosensory and motor center subarea AV primary auditory center subarea AV Johnston organ neuron bundle AV JON-AV fly_anatomy.ontology JON bundle AV VFB:FBbt_00047896 antennal mechanosensory and motor center zone A