part of continuous with synaptic neuropil subdomain subregion AA of AMMC zone A subregion AP of AMMC zone A JON-AP FlyBrain_NDB:10186 primary auditory center subarea AP VFB:FBbt_00047900 Johnston organ neuron bundle AP bundle A posterior fly_anatomy.ontology Subregion of AMMC zone A. This region contains the remainder of bundle A (zone A) of Johnston organ neuron axons as it projects posteriorly within the AMMC after the branching of subregions AD and AV. It is rich with the presynapses of Johnston organ neurons. JON bundle AP antennal mechanosensory and motor center subarea AP FBbt:00047900 antennal mechanosensory and motor center zone A