The expression of α-Spec^{dsRNA.Scer\UAS} under the control of Scer\GAL4^Or47b.7.467 leads to adult olfactory receptor neurons Or47b with a significant decrease in the number of pre-synaptic sites, as assessed by an active zone marker, as compared to controls; expression under the control of Scer\GAL4^Or67d-GAL4-1 results in no obvious morphological defects in adult antennal lobe glomeruli DA1 but their associated adult olfactory receptor neurons Or67d present a significant decrease in the number of pre-synaptic sites, as compared to controls.

Expression of α-Spec^{dsRNA.Scer\UAS} in the muscle (under the control of Scer\GAL4^C57) significantly reduces the number of synaptic boutons.

Expression of α-Spec^{dsRNA.Scer\UAS} postsynaptically in the muscle (under the control of Scer\GAL4^C57) results in a dramatic increase in the average amplitude of spontaneous miniature relase events (mepsp <up>miniature excitory postsynaptic potential</up>; quantal size). There is an increase in EPSP ampltidue that parallels the increase in quantal size.

Although expression of α-Spec^{dsRNA.Scer\UAS}, under the control of Scer\GAL4^elav-C155, causes late larval lethality, a small proportion of escapers survive to early adult stages. Expression of α-Spec^{dsRNA.Scer\UAS} in the presynapse, driven by Scer\GAL4^elav-C155, causes an increase in the number and extent of synaptic retraction events compared to wild-type synapses. The severity of synapse retraction correlates with a decrease in frequency, but not amplitude, of spontaneous miniature release events and a decreased quantal content, but no change in quantal size. Bouton morphology is affected; boutons show a similar active zone organization to wild type, but presynaptic vesicle density is severely decreased and vacuoles are sometimes present. The postsynaptic SSR is disrupted, although the extent of this varies from bouton to bouton; in severe cases, the SSR is disorganized and becomes invaded by muscle tissue. The microtubule network is disorganized in the nerve terminals of Scer\GAL4^elav-C155>α-Spec^{dsRNA.Scer\UAS} mutants. Microtubules are thicker than wild type and do not extend to the distal end of the synaptic bouton chain. Axons of the peripheral nervous system show large accumulations of vesicles, although there is only a minor axonal microtubule disorganization. Postsynaptic α-Spec^{dsRNA.Scer\UAS} expression, driven by Scer\GAL4^C57, causes defects in the integrity of the subsynaptic membrane folds but does not cause increased synapse retraction.