Expression of Grip^{dsRNA.Scer\UAS} under the control of Scer\GAL4^C164 pre-synaptically, and post-synaptically results in a decrease in the number of synaptic boutons. Boutons were observed with an atypical shape. These boutons, termed 'ghost' boutons, exhibit a rounded appearance, as opposed to the more elliptical appearance of Type I boutons. In addition, a thin neuronal process connecting the ghost bouton with a main neuromuscular branch can occasionally be discerned. Most ghost boutons are devoid of active zones, although the occasional ghost bouton contains a few active zones.

Expression of Grip^{dsRNA.Scer\UAS} in postsynaptic muscles (under the control of Scer\GAL4^C57) results in a population of synaptic boutons that are filled with synaptic vesicles but are devoid of active zones or postsynaptic specialisations, including postsynaptic densities and subsynaptic reticulum.