Expression of Hsap\SETXR1363X.Scer\UAS under the control of Scer\GAL4elav-C155 (but not Scer\GAL4Mef2.PU) results in increased average number as well as area of boutons on neuromuscular junctions in third instar larvae, but no defects in neural electrophysiology are observed at the junctions (no change in amplitudes of either evoked or miniature junction potential, EJP, quantal content and no significant decline in EJP amplitudes over prolonged high-frequency stimulation).