Direct Current Stimulation Modulates Synaptic Facilitation via Distinct Presynaptic Calcium Channels
Sreerag Othayoth Vasu1, Hanoch Kaphzan1
1Sagol Department of Neurobiology, University of Haifa, Haifa 3103301, Israel.
International Journal of Molecular Sciences
|December 9, 2023
Summary
Direct current stimulation (DCS) modulates brain activity by affecting presynaptic calcium channels. P/Q and N-type channels are key to this process, influencing synaptic vesicle release, while T-type channels are not involved.
Area of Science:
- Neuroscience
- Electrophysiology
- Cellular Biology
Background:
- Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique used to treat neuropsychiatric disorders.
- The precise molecular mechanisms underlying tDCS effects, particularly at the level of neuronal compartments, remain incompletely understood.
- Axon terminals are crucial for synaptic transmission and are sensitive to electrical fields, suggesting a potential site of tDCS action.
Purpose of the Study:
- To investigate the role of specific voltage-dependent calcium channel subtypes in mediating the effects of direct current stimulation (DCS) on synaptic vesicle release.
- To elucidate the mechanism by which DCS modulates presynaptic function and synaptic facilitation.
Main Methods:
- Recording of spontaneous excitatory postsynaptic currents (sEPSCs) in cortical layer-V pyramidal neurons.
- Application of direct current stimulation (DCS) to neurons.
- Selective pharmacological inhibition of different voltage-dependent calcium channel subtypes (P/Q, N, and T-type).
Main Results:
- DCS significantly altered sEPSCs, indicating modulation of spontaneous vesicle release.
- Inhibition of P/Q-type or N-type calcium channels blocked the effects of DCS on sEPSCs.
- Inhibition of T-type calcium channels did not affect the DCS-induced modulation of sEPSCs.
Conclusions:
- DCS modulates synaptic vesicle release by regulating presynaptic calcium channels in axon terminals.
- P/Q-type and N-type calcium channels are critically involved in the axonal effects of DCS.
- T-type calcium channels do not play a significant role in the DCS-induced modulation of synaptic facilitation.
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