Overexpression of GluRIIA^Scer\UAS.cPa under the regulation of the muscle-specific driver Scer\GAL4^Mhc.PW results in a significant elevation in the junctional GluRIIA immunoreactivity that is primarily attributable to an increase in the number of GluRIIA-positive synapses (similar to a pAbp^k10109/+ mutant). Overexpression of GluRIIA^Scer\UAS.cPa under the regulation of the muscle-specific driver Scer\GAL4^Mhc.PW results in a significantly elevated frequency of mEJCs, an enhanced evoked release of presynaptic vesicles and unaltered quantal sizes, similar to pAbp^k10109/+ mutants. Overexpression of GluRIIA^Scer\UAS.cPa under the regulation of the muscle-specific drivers Scer\GAL4^Mhc.PW or Scer\GAL4^how-24B results in enlarged larval stage neuromuscular junctions (NMJs) compared with controls (e.g. GAL4 line alone, or wild-type). The larger size of NMJ is evident in a significant increase in the number of synaptic boutons, which are wild-type in shape and size. In addition, the number of boutons and the strength of evoked signal transmission of GluRIIA^Scer\UAS.cPa expressing NMJs (under the control of Scer\GAL4^Mhc.PW) show a similar relationship as seen in animals with elevated subsynaptic translation (pAbp^k10109/+).

The quantal size at the neuromuscular junction is larger in Df(2L)SP22 larvae rescued with GluRIIA^Scer\UAS.cPa expressed under the control of Scer\GAL4^how-24B than in Df(2L)SP22 larvae rescued with GluRIIB^Scer\UAS.cDa expressed under the control of Scer\GAL4^how-24B.

When expressed via Scer\GAL4^how-24B, expression of GluRIIA^Scer\UAS.cPa leads to an increase in quantal size, by 35-59% (depending on effective copy number of transgene), with no compensatory down-regulation of quantal content.