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Evaluation of Synaptic Multiplicity Using Whole-cell Patch-clamp Electrophysiology
Published on: April 23, 2019
Variability of quantal synaptic currents in thalamocortical neurons.
M Neubig1, A Destexhe, T J Sejnowski
1Computational Neurobiology Laboratory, Salk Institute for Biological Studies, Howard Hughes Medical Institute, La Jolla, CA 92037, USA.
Thalamus & Related Systems
|November 26, 2009
Summary
Intra-synaptic organization, not external factors, primarily determines synaptic variability in thalamocortical neurons. Computational models reveal internal synaptic mechanisms are more influential than previously thought.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Synaptic Plasticity
Background:
- Quantal synaptic currents (minis) exhibit broad amplitude variability and skewed distributions at central synapses.
- The precise sources contributing to this variability remain under investigation.
Purpose of the Study:
- To computationally model thalamocortical neurons to differentiate between intra- and extra-synaptic contributions to synaptic variability.
- To identify the primary drivers of synaptic current variability in these neurons.
Main Methods:
- Utilized computational models of thalamocortical neurons.
- Separated intra-synaptic and extra-synaptic sources of variability.
- Simulated effects of local input resistance and dendritic filtering.
- Tested multiple release models to assess their impact on synaptic distributions.
Main Results:
- External factors (input resistance, dendritic filtering) contributed minimally (<10%) to synaptic variability and primarily introduced negative skew.
- These external factors showed limited capacity to reduce positive skew.
- Multiple release models generated non-physiological, multi-peaked distributions.
Conclusions:
- Intra-synaptic organization is the principal determinant of synaptic variability in thalamocortical neurons.
- Extra-synaptic mechanisms exert a stronger influence on variability than initially suggested by data.
- Thalamocortical neurons, particularly in rodents, offer a valuable model for studying synaptic variability and its functional outcomes.
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