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Dual Electrophysiological Recordings of Synaptically-evoked Astroglial and Neuronal Responses in Acute Hippocampal Slices
Published on: November 26, 2012
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Rapid astrocyte-dependent facilitation amplifies multi-vesicular release in hippocampal synapses
Jongyun Myeong1, Vitaly A Klyachko1
1Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63132, USA.
Cell Reports
|December 14, 2022
Summary
A novel form of synaptic facilitation, dependent on prior glutamate release, enhances vesicle release probability. This astrocyte-mediated process amplifies neurotransmission and shows distinct spatiotemporal clustering.
Area of Science:
- Neuroscience
- Cell Biology
- Synaptic Plasticity
Background:
- Synaptic facilitation, a key short-term plasticity mechanism, is typically linked to presynaptic calcium.
- Understanding the precise mechanisms regulating synaptic facilitation is crucial for comprehending neural circuit function.
Purpose of the Study:
- To investigate a distinctive form of synaptic facilitation.
- To elucidate the role of astrocytes and glutamate uptake in this facilitation process.
- To characterize the spatiotemporal properties of release-dependent facilitation.
Main Methods:
- Utilized near-total internal reflection fluorescence (near-TIRF) imaging.
- Analyzed single vesicle release events in cultured hippocampal synapses.
- Investigated the necessity of astrocyte contact and astrocytic glutamate uptake (EAAT1).
Main Results:
- Identified a release-dependent facilitation where successful release increases subsequent release probability.
- Demonstrated this facilitation requires astrocyte contact and EAAT1-mediated glutamate uptake.
- Observed facilitation onset within 500 ms, lasting seconds, leading to clustered release events.
- Showcased amplification of multi-vesicular release with preferential active zone center localization.
Conclusions:
- Uncovered a rapid, astrocyte-dependent form of synaptic facilitation.
- This facilitation modulates multi-vesicular release through a mechanism distinct from residual calcium.
- The findings highlight a novel interaction between astrocytes and neuronal activity in shaping synaptic transmission.
