Spontaneous Synaptic Activity
Spontaneous Synaptic Activity - Related Videos
08:10
Examination of Synaptic Vesicle Recycling Using FM Dyes During Evoked, Spontaneous, and Miniature Synaptic Activities
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Cited by 29 •
2014
We describe the use of styryl FM dyes to image synaptic vesicle recycling in functional nerve terminals. This protocol can be applied not only to evoked, but also spontaneous and miniature synaptic activities. The protocol expands the variety of synaptic events that can be effectively evaluated.
08:06
Determination of the Spontaneous Locomotor Activity in Drosophila melanogaster
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Cited by 16 •
2014
Drosophila melanogaster are useful in studying genetic or environmental manipulations that affect behaviors such as spontaneous locomotor activity. Here we describe a protocol that utilizes monitors with infrared beams and data analysis software to quantify spontaneous locomotor...
02:21
Spontaneity
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2020
A spontaneous process is one that occurs naturally under certain conditions. A nonspontaneous process, on the other hand, will not take place unless it is “driven” by the continual input of energy from an external source. Processes have a natural tendency to occur in one direction under a given set of conditions. Water will naturally flow downhill (spontaneous process), but uphill flow (nonspontaneous process) requires outside intervention such as the use of a pump. Iron exposed to the earth’s...
10:19
Induction of an Isoelectric Brain State to Investigate the Impact of Endogenous Synaptic Activity on Neuronal Excitability In Vivo
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Cited by 3 •
2016
This procedure performs long-lasting in vivo intracellular recordings from single neurons during physiologically relevant cerebral states and after complete abolition of ongoing electrical activities, resulting in an isoelectric brain state. The physiological constants of the animal are carefully monitored during the transition to the artificial comatose condition.
08:46
Studying Synaptic Vesicle Pools using Photoconversion of Styryl Dyes
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Cited by 18 •
2010
FM dyes have been of invaluable help in the understanding of synaptic dynamics. FMs are normally followed under the fluorescent microscope during different stimulation conditions. However, photoconversion of FM dyes combined with electron microscopy allows the visualization of distinct synaptic vesicle pools, among other ultrastructure components, in synaptic boutons.
FAQs
Random fusion of synaptic vesicles with the presynaptic membrane produces discrete neurotransmitter release events without requiring an action potential. Each fusion event can activate ligand-gated receptors on the receiving neuron, creating a miniature excitatory or inhibitory postsynaptic current. This stochastic release provides a continuing baseline against which synaptic function can be evaluated.
Event frequency and amplitude provide different clues about synaptic function. Changes in frequency can indicate altered neurotransmitter release probability or synaptic connectivity, whereas changes in amplitude can reflect altered receptor function on the receiving cell. Examining both measures helps researchers distinguish presynaptic changes from postsynaptic changes rather than treating all activity differences as equivalent.
Miniature currents may be excitatory or inhibitory because released neurotransmitter can act through different ligand-gated receptors. Recording both types allows researchers to examine how synaptic inputs influence neuronal signaling rather than focusing on transmission in only one direction. This distinction is especially relevant when studying circuit formation, because developing networks must establish coordinated patterns of opposing synaptic effects.
The defining experimental distinction is whether transmission depends on action potentials. Spontaneous events arise from vesicle fusion that occurs independently of those electrical impulses, so they provide information about baseline synaptic operation. Comparing this baseline with activity-dependent transmission can help separate intrinsic release behavior from changes caused by action-potential recruitment of synaptic signaling.
Researchers record miniature excitatory or inhibitory postsynaptic currents generated when randomly released neurotransmitter activates receptors on a receiving neuron. The resulting event distributions can be analyzed for frequency and amplitude. These measurements provide functional evidence about neurotransmitter release, receptor responsiveness, and the presence or strength of synaptic connections, even when action-potential-driven signaling is not being assessed.
This approach is useful when researchers need a functional readout of synapses rather than structural evidence alone. It can assess neurotransmitter release probability, receptor function, and synaptic connectivity, while changes across development can reveal how circuits form. The same measurements also support studies of synaptic plasticity and neurological disease by identifying altered presynaptic or postsynaptic function.