Inactivation of presynaptic calcium current contributes to synaptic depression at a fast central synapse
| Autor: | Tetsuhiro Tsujimoto, Matthew F. Cuttle, Ian D. Forsythe, Margaret Barnes-Davies, Tomoyuki Takahashi |
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| Rok vydání: | 1998 |
| Předmět: |
Squid giant synapse
P-type calcium channel Neuroscience(all) Spider Venoms In Vitro Techniques Membrane Potentials 03 medical and health sciences 0302 clinical medicine omega-Agatoxin IVA Postsynaptic potential omega-Conotoxin GVIA Synaptic augmentation Reaction Time Animals Rats Wistar Evoked Potentials 030304 developmental biology 0303 health sciences Voltage-dependent calcium channel Chemistry General Neuroscience T-type calcium channel Rats Inbred Strains Calcium Channel Blockers Rats R-type calcium channel Barium Strontium Synapses Biophysics Calcium Nimodipine Calcium Channels Peptides Calyx of Held Neuroscience 030217 neurology & neurosurgery Brain Stem |
| Zdroj: | Neuron. 20(4) |
| ISSN: | 0896-6273 |
| Popis: | Voltage-gated calcium channels are well characterized at neuronal somata but less thoroughly understood at the presynaptic terminal where they trigger transmitter release. In order to elucidate how the intrinsic properties of presynaptic calcium channels influence synaptic function, we have made direct recordings of the presynaptic calcium current (IpCa) in a brainstem giant synapse called the calyx of Held. The current was pharmacologically classified as P-type and exhibited marked inactivation. The inactivation was largely dependent upon the inward calcium current magnitude rather than the membrane potential, displayed little selectivity between divalent charge carriers (Ca2+, Ba2+ and Sr2+), and exhibited slow recovery. Simultaneous pre- and postsynaptic whole-cell recording revealed that IpCa inactivation predominantly contributes to posttetanic depression of EPSCs. Thus, because of its slow recovery, IpCa inactivation underlies this short-term synaptic plasticity. |
| Databáze: | OpenAIRE |
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