Expression of Syt4wt.Scer\UAS post-synaptically under the control of Scer\GAL4Mhc.PW results in an approximate 60% increase in bouton number.
Expression of Syt4wt.Scer\UAS post-synaptically under the control of Scer\GAL4Mhc.PW results in enhanced spontaneous neurotransmitter release in the absence of nerve stimulation and enhanced evoked neurotransmission (at 0.5mM Ca[2+] concentration). These changes in evoked responses are not observed in 2.0mM extracellular Ca[2+] concentration, suggesting that alterations in release probability or vesicle pool size may compensate for the altered number of release sites. The fast component of synaptic depression release during initial stimulation is unchanged. However, overexpression larvae show more depression and a smaller steady-state response during the train.
Overexpression of Syt4wt.Scer\UAS post-synaptically under the control of Scer\GAL4Mhc.PW triggers an elevation in the frequency of spontaneous fusion after high frequency stimulation compared with wild-type synapses, with spontaneous release rates often >15Hz.