Premium
Presynaptic action potential waveform determines cortical synaptic latency
Author(s) -
Boudkkazi Sami,
FronzaroliMolinieres Laure,
Debanne Dominique
Publication year - 2011
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2010.199653
Subject(s) - neuroscience , excitatory postsynaptic potential , chemistry , neurotransmission , synaptic potential , synaptic fatigue , synaptic augmentation , synaptic plasticity , inhibitory postsynaptic potential , biology , receptor , biochemistry
Non‐technical summary Synaptic delay at cortical synapses is determined by the presynaptic release probability. We show here that the duration and amplitude of the presynaptic action potential also determine synaptic latency at neocortical and hippocampal excitatory synapses. Broadening the presynaptic spike with blockers of potassium channels increased latency by 1–2 ms. Decreasing the amplitude of the presynaptic action potential by partly blocking sodium channels reduced synaptic latency by ∼0.5 ms. These changes may contribute to stabilization of synaptic timing during repetitive stimulation. The regulation of synaptic timing by these pharmacological agents could not be attributed to modulation of axonal conduction. Rather, the effects are compatible with modifications of the kinetics of the presynaptic calcium current. We conclude that synaptic latency at cortical neurons is not constant but dynamically regulated by presynaptic action potential waveform.