Evidence for a role for synaptophysin in expression of long-term potentiation in rat dentate gyrus.
Maintenance of long-term potentiation in perforant path-granule cell synapses is accompanied by increased glutamate release. Here we investigate the role of synaptophysin in release and in expression of long-term potentiation in dentate gyrus. We report that long-term potentiation was accompanied by increased endogenous glutamate release and increased tyrosine phosphorylation of synaptophysin, but these changes were attenuated when long-term potentiation was inhibited by the tyrosine kinase inhibitor tyrphostin AG879 or by the NMDA antagonist D-aminophosphonovalerate. In vitro analysis revealed that KCl-induced glutamate release was abolished in synaptosomes prepared in the presence of antisynaptophysin. The data suggest a role for synaptophysin in release and indicate that activation of tyrosine kinase and synaptophysin phosphorylation contribute to long-term potentiation perhaps by modulating glutamate release.
Department of Physiology, Trinity College, Dublin, Ireland.
P M
PM
Mullany
M A
MA
Lynch
D000818:Animals; D018891:Dentate Gyrus / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology*; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D019580:Perforant Pathway / Q000187:drug effects / Q000502:physiology; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D016708:Synaptophysin / Q000096:biosynthesis* / Q000187:drug effects / Q000502:physiology*; D014443:Tyrosine / Q000378:metabolism / Q000502:physiology; D020032:Tyrphostins / Q000494:pharmacology
D004791:Enzyme Inhibitors; D016708:Synaptophysin; D020032:Tyrphostins; D018698:Glutamic Acid; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases