Journal articles
Analog modulation of spike-evoked transmission in CA3 circuits is determined by axonal Kv1.1 channels in a time-dependent manner
Abstract : Synaptic transmission usually depends on action potentials (APs) in an all-or-none (digital) fashion. Recent studies indicate, however , that subthreshold presynaptic depolarization may facilitate spike-evoked transmission, thus creating an analog modulation of spike-evoked synaptic transmission, also called analog–digital (AD) synaptic facilitation. Yet, the underlying mechanisms behind this facilitation remain unclear. We show here that AD facilitation at rat CA3–CA3 synapses is time-dependent and requires long presynaptic depolarization (5–10 s) for its induction. This depolarization-induced AD facilitation (d-ADF) is blocked by the specific Kv1.1 channel blocker dendrotoxin-K. Using fast voltage-imaging of the axon, we show that somatic depolarization used for induction of d-ADF broadened the AP in the axon through inactivation of Kv1.1 channels. Somatic depolarization enhanced spike-evoked calcium signals in presynaptic terminals, but not basal calcium. In conclusion, axonal Kv1.1 channels determine glutamate release in CA3 neurons in a time-dependent manner through the control of the presynaptic spike waveform.
Cited literature [41 references]
https://hal-amu.archives-ouvertes.fr/hal-01766833
Contributor : Dominique Debanne <>
Submitted on : Wednesday, April 25, 2018 - 11:45:52 AM
Last modification on : Wednesday, December 9, 2020 - 3:12:31 AM
Long-term archiving on: : Tuesday, September 18, 2018 - 9:20:40 AM
Contributor : Dominique Debanne <>
Submitted on : Wednesday, April 25, 2018 - 11:45:52 AM
Last modification on : Wednesday, December 9, 2020 - 3:12:31 AM
Long-term archiving on: : Tuesday, September 18, 2018 - 9:20:40 AM
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Bialowas-Debanne-EJN-2015.pdf
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