Absence of junctional glutamate receptor clusters in Drosophila mutants lacking spontaneous transmitter release.
Little is known about the functional significance of spontaneous miniature synaptic potentials, which are the result of vesicular exocytosis at nerve terminals. Here, by using Drosophila mutants with specific defects in presynaptic function, we found that glutamate receptors clustered normally at neuromuscular junctions of mutants that retained spontaneous transmitter secretion but had lost the ability to release transmitter in response to action potentials. In contrast, receptor clustering was defective in mutants in which both spontaneous and evoked vesicle exocytosis were absent. Thus, spontaneous vesicle exocytosis appears to be tightly linked to the clustering of glutamate receptors during development.
Saitoe
M
M
Institute for Behavioral Sciences, Gunma University School of Medicine, Maebashi, Gunma 371-8511, Japan. saitoe@tmin.ac.jp
Schwarz
T L
TL
Umbach
J A
JA
Gundersen
C B
CB
Kidokoro
Y
Y
D000200:Action Potentials; D000818:Animals; D004330:Drosophila / Q000196:embryology / Q000235:genetics / Q000502:physiology; D005089:Exocytosis; D018698:Glutamic Acid / Q000494:pharmacology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009469:Neuromuscular Junction / Q000196:embryology / Q000378:metabolism / Q000502:physiology*; D017729:Presynaptic Terminals / Q000378:metabolism / Q000502:physiology; D050765:Qa-SNARE Proteins; D050683:R-SNARE Proteins; D011940:Receptor Aggregation; D017470:Receptors, Glutamate / Q000378:metabolism*; D013111:Spider Venoms / Q000494:pharmacology; D013570:Synaptic Membranes / Q000378:metabolism / Q000502:physiology*; D009435:Synaptic Transmission; D013572:Synaptic Vesicles / Q000378:metabolism / Q000502:physiology*; D013696:Temperature; D013779:Tetrodotoxin / Q000494:pharmacology; D019076:Transgenes
D008565:Membrane Proteins; D050765:Qa-SNARE Proteins; D050683:R-SNARE Proteins; D017470:Receptors, Glutamate; D013111:Spider Venoms; D018698:Glutamic Acid; D013779:Tetrodotoxin