English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In this study we established a transgenic Ca2+imaging technique in Drosophila that enabled us to target the Ca2+ sensor protein yellow Cameleon-2 specifically to larval neurons. This noninvasive method allowed us to measure evoked Ca2+ signals in presynaptic terminals of larval neuromuscular junctions (NMJs). We combined transgenic Ca2+ imaging with electrophysiological recordings and morphological examinations of larval NMJs to analyze the mechanisms underlying persistently enhanced evoked vesicle release in two independent mutants. We show that persistent strengthening of junctional vesicle release relies on the recruitment of additional active zones, the spacing of which correlated with the evoked presynaptic Ca2+ dynamics of individual presynaptic terminals. Knock-out mutants of the postsynaptic glutamate receptor (GluR) subunit DGluR-IIA, which showed a reduced quantal size, developed NMJs with a smaller number of presynaptic boutons but a strong compensatory increase in the density of active zones. This resulted in an increased evoked vesicle release on single action potentials and larger evoked Ca2+signals within individual boutons; however, the transmission of higher frequency stimuli was strongly depressed. A second mutant (pabpP970/+), which showed enhanced evoked vesicle release triggered by elevated subsynaptic protein synthesis, developed NMJs with an increased number of presynaptic boutons and active zones; however, the density of active zones was maintained at a value typical for wild-type animals. This resulted in wild-type evoked Ca2+ signals but persistently strengthened junctional signal transmission. These data suggest that the consolidation of strengthened signal transmission relies not only on the recruitment of active zones but also on their equal distribution in newly grown boutons.

Differential Regulation of Active Zone Density during Long-Term Strengthening ofDrosophilaNeuromuscular Junctions