Aging Drosophila melanogaster display altered pre- and postsynaptic ultrastructure at adult neuromuscular junctions.
Although age-related changes in synaptic plasticity are an important focus within neuroscience, little is known about ultrastructural changes of synaptic morphology during aging. Here we report how aging affects synaptic ultrastructure by using fluorescence and electron microscopy at the adult Drosophila neuromuscular junction (NMJ) of ventral abdominal muscles. Mainly four striking morphological changes of aging NMJs were revealed. 1) Bouton size increases with proportionally rising number of active zones (AZs). 2) Synaptic vesicle density at AZs is increased in old flies. 3) Late endosomes, cisternae, and multivesicular bodies accumulate in the presynaptic terminal, and vesicles accumulate between membranes of the terminal bouton and the subsynaptic reticulum. 4) The electron-dense pre- and postsynaptic apposition is expanded in aging NMJs, which is accompanied by an expansion of the postsynaptic glutamate receptor fields. These findings suggest that aging is possibly accompanied by impaired synaptic vesicle release and recycling and a potentially compensatory expansion of AZs and postsynaptic densities.
Institute of Anatomy and Cell Biology, University of Wuerzburg, 97070, Wuerzburg, Germany.
Nicole
N
Wagner
Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152, Martinsried, Germany.
Ulrike
U
Laugks
Institute of Physiology-Neurophysiology, Julius-Maximilians University Wuerzburg, 97070, Wuerzburg, Germany.
Manfred
M
Heckmann
Institute of Anatomy and Cell Biology, University of Wuerzburg, 97070, Wuerzburg, Germany.
Esther
E
Asan
Institute of Physiology-Neurophysiology, Julius-Maximilians University Wuerzburg, 97070, Wuerzburg, Germany.
Kirsa
K
Neuser
D000375:Aging / Q000473:pathology*; D000818:Animals; D048429:Cell Size; D004331:Drosophila melanogaster / Q000648:ultrastructure*; D011992:Endosomes / Q000648:ultrastructure; D005260:Female; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D009469:Neuromuscular Junction / Q000648:ultrastructure*; D009473:Neuronal Plasticity; D017729:Presynaptic Terminals / Q000648:ultrastructure*; D016019:Survival Analysis; D013572:Synaptic Vesicles / Q000648:ultrastructure
AB_2491007; AB_2491008; AB_528108; Drosophila; SciRes_000184; aging; neuromuscular junction; nif-0000-00241; nif-0000-30467; ultrastructure