Related Experiment Video
Updated: May 21, 2026
11:02
Presynaptically Silent Synapses Studied with Light Microscopy
Published on: January 4, 2010
Snapin is critical for presynaptic homeostatic plasticity
Dion K Dickman1, Amy Tong, Graeme W Davis
1Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, California 94158, USA.
Summary
Snapin protein is crucial for maintaining synaptic homeostasis, a process that regulates neurotransmitter release. Its absence disrupts this essential communication pathway between neurons, impacting synaptic plasticity.
Area of Science:
- Neuroscience
- Molecular Biology
- Genetics
Background:
- The mechanisms controlling presynaptic neurotransmitter release during synaptic homeostasis are not fully understood.
- A previous genetic screen identified dysbindin's role in synaptic homeostasis at the Drosophila melanogaster neuromuscular junction.
Purpose of the Study:
- To investigate the role of Snapin, a protein interacting with dysbindin, in the homeostatic modulation of presynaptic neurotransmitter release.
- To determine if Snapin is involved in synaptic homeostasis mechanisms.
Main Methods:
- Utilized electrophysiology in Drosophila melanogaster to study synaptic transmission.
- Performed genetic manipulation, including gene deletion and pharmacological inhibition of postsynaptic glutamate receptors.
- Assessed baseline synaptic transmission, synapse morphology, growth, and active zone characteristics.
Main Results:
- Loss of snapin function completely blocked homeostatic modulation of presynaptic vesicle release.
- This blockade occurred with both rapid (pharmacological) and long-term (genetic) induction of synaptic homeostasis.
- Snapin deficiency did not affect baseline transmission, synapse morphology, growth, or active zone properties, ruling out developmental defects.
Conclusions:
- Snapin is essential for synaptic homeostasis, specifically in modulating presynaptic vesicle release.
- Snapin likely functions with dysbindin to regulate vesicle release and homeostatic plasticity.
- Snapin's interaction with SNAP25 is also implicated in synaptic homeostasis.
Related Concept Videos
01:01Neuroplasticity
Neuroplasticity reflects the brain's remarkable capacity to adapt and evolve, responding dynamically to learning, experiences, or injury by reorganizing its neural circuitry. This reorganization involves creating new neural connections and refining old ones through a series of biological processes that contribute to the brain's lifelong development and adaptability.
01:32Postsynaptic Potential (PSP)
Postsynaptic potential (PSP) refers to a change in the electrical potential of a neuron when neurotransmitters released by presynaptic neurons bind to postsynaptic receptors. This potential can either be excitatory, leading to depolarization and ultimately action potential generation, or inhibitory, leading to hyperpolarization and suppression of the postsynaptic neuron.
There are two types of receptors: ionotropic and metabotropic.
The ionotropic receptor is the membrane protein that has an...
There are two types of receptors: ionotropic and metabotropic.
The ionotropic receptor is the membrane protein that has an...
01:25Long-term Potentiation
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
Hebbian LTP
LTP can occur when presynaptic neurons...
Hebbian LTP
LTP can occur when presynaptic neurons...
01:35Long-term Potentiation
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTP is the process of synaptic strengthening that occurs over time between pre- and postsynaptic neuronal connections. The synaptic strengthening of LTP works in opposition to the synaptic weakening of long-term depression (LTD) and together are the main mechanisms that underlie learning and memory.
01:28Integration of Synaptic Events
Synaptic integration mainly includes the summation of graded potentials. Graded potentials, regardless of their type, cause subtle alterations in membrane voltage, resulting in either depolarization or hyperpolarization. These incremental changes, when combined or summed, can propel the neuron toward its threshold. Consider, for example, a membrane experiencing a +15 mV shift, causing it to depolarize from -70 mV to -55 mV. In this scenario, graded potentials govern the membrane's ability to...
01:09Synaptic Signaling
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...