Presynaptic calcium currents and their relation to synaptic transmission: Voltage clamp study in squid giant synapse and theoretical model for the calcium gate
AUTOR(ES)
Llinás, Rodolfo
RESUMO
A voltage clamp study of the presynaptic terminal in squid stellate ganglion has given quantitative results relating inward Ca2+ current to presynaptic membrane potential and postsynaptic response to inward Ca2+ current. The results indicate an S-shaped curve for the relationship between presynaptic potential and Ca2+ current and a linear relationship between Ca2+ current and postsynaptic potential. A similar S-shaped curve was found for the time-dependent properties of the Ca2+ conductance. Based on these results a mathematical model was developed which accounts for the experimental results in this and previously published papers by other authors. The model suggests that five subunits are involved in the Ca2+ gate and that the subunits change noncooperatively from an inactive to an active form upon membrane depolarization.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=430802Documentos Relacionados
- Transmission at voltage-clamped giant synapse of the squid: evidence for cooperativity of presynaptic calcium action.
- Calcium dependence of presynaptic calcium current and post-synaptic response at the squid giant synapse.
- Role of presynaptic calcium ions and channels in synaptic facilitation and depression at the squid giant synapse.
- Transmission by presynaptic spike-like depolarization in the squid giant synapse.
- The inositol high-polyphosphate series blocks synaptic transmission by preventing vesicular fusion: a squid giant synapse study.