RT Journal Article
SR Electronic
T1 Synaptic vesicle dynamics in living cultured hippocampal neurons visualized with CY3-conjugated antibodies directed against the lumenal domain of synaptotagmin
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 4328
OP 4342
DO 10.1523/JNEUROSCI.15-06-04328.1995
VO 15
IS 6
A1 K Kraszewski
A1 O Mundigl
A1 L Daniell
A1 C Verderio
A1 M Matteoli
A1 P De Camilli
YR 1995
UL http://www.jneurosci.org/content/15/6/4328.abstract
AB Antibodies directed against the lumenal domain of synaptotagmin I conjugated to CY3 (CY3-Syt1-Abs) and video microscopy were used to study the dynamics of synaptic vesicles in cultured hippocampal neurons. When applied to cultures after synapse formation, CY3-Syt1-Abs produced a strong labeling of presynaptic vesicle clusters which was markedly increased by membrane depolarization. The increase of the rate of CY3-Syt1-Ab uptake in a high K+ medium was maximal during the first few minutes but persisted for as long as 60 min. In axons developing in isolation, CY3-Syt1-Abs, in combination with electron microscopy immunocytochemistry, revealed the presence of synaptic vesicle clusters which move in bulk in anterograde and retrograde direction. Clusters are present both in the axon shaft and in filopodia but not in the filopodia of the growth cone. Both presynaptic vesicle clusters and clusters present in isolated axons were disrupted by okadaic acid as previously shown for synaptic vesicle clusters at the frog neuromuscular junction. These findings indicate that synaptic vesicle aggregation may occur independently of cell-cell interaction, but that, in the absence of a synaptic contact, vesicle clusters are not stably anchored to a given region of the cell surface. Labeling of synaptic vesicles in immature isolated neurons was found to be depolarization and Ca2+ dependent, demonstrating that Ca(2+)-regulated exocytosis is an intrinsic characteristic of synaptic vesicles irrespective of their localization at a synapse.