myo7aa−/− mutant ribbon synapse abnormalitiesarediminishedafterexposure to (R)-Baclofen. (A-E) Representative TEM images showing ribbon synapses of untreated wild-type (A) and untreated myo7aa−/− mutant (B) larvae, as well as myo7aa−/− mutants treated with 5 µM (±)-Bay K 8644 (C), 250 µM Nefiracetam (D) or 125 µM (R)-Baclofen (E). All images were taken at 5 dpf. Scale bars: 1000 nm. (F) The ribbon area in untreated myo7aa−/− is smaller compared to that in myo7aa−/− treated with 125 µM (R)-Baclofen. Ribbon synapses of untreated wild-type larvae have a ribbon area comparable to that of myo7aa−/− mutants treated with 125 µM (R)-Baclofen (two-tailed t-test). (G) Ribbons of untreated myo7aa−/− mutants have fewer tethered vesicles compared to those of myo7aa−/− mutants treated with 125 µM (R)-Baclofen. Ribbons of untreated wild-type larvae have a number of tethered vesicles comparable to those of myo7aa−/− larvae treated with 125 µM (R)-Baclofen (two-tailed t-test). Bold black lines represent the mean of the data set and error bars are 95% confidence intervals. Experiments were replicated three times for myo7aa−/− mutants treated with each drug.
|