Presynaptic voltage facilitation of synaptic transmission between CA3-CA3 pyramidal neurons

• Autorzy: Bialowas A. , Rama S. , Zbili M. , Fronzaroli-Molinieres L. , Ankiri N. , Carlier E. , Debanne D.
• Języki publikacji: EN

Abstrakty

EN

Synaptic transmission in the brain generally depends on action potentials. However, subthreshold variation in presynaptic membrane potential also determines spike-evoked transmission. We show here that excitatory synaptic transmission at CA3–CA3 connections depends on the membrane potential of the presynaptic neuron. Connected CA3 pyramidal neurons were recorded and synaptic transmission was tested when the presynaptic neurone was held at −61 mV, −77 mV or −48 mV. The presynaptic voltage facilitation (PVF) of synaptic transmission quantified by normalizing the postsynaptic responses obtained at −48 mV to those measured at −77 mV amounted to 135 ± 14% (n=13). PVF was associated with a decrease in the paired-pulse ratio and was totally occluded by bath application of the Kv1 channel blocker dendrotoxin (DTX). Using confocal laser scanning microscopy, we measured calcium transients evoked by the propagated spike in axons (50–250 µm from the soma) of CA3 neurons loaded with Fluo-4. Depolarization of the cell body from −75 to −50 mV enhanced spike-evoked calcium transients by ~17%. We conclude that PVF is a short-term plasticity at excitatory CA3–CA3 synapses resulting from the increase in spike-evoked calcium transients in the axon caused by voltage-inactivation of Kv1 channels.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2012
• Tom: 72
• Numer: 2
• Opis fizyczny: p.201

Twórcy

autor

Bialowas A.

• Faculte de Medicine, Aix-Marseille Universite, Campus Nord, Marseille, France

autor

Rama S.

• Faculte de Medicine, Aix-Marseille Universite, Campus Nord, Marseille, France

autor

Zbili M.

• Faculte de Medicine, Aix-Marseille Universite, Campus Nord, Marseille, France

autor

Fronzaroli-Molinieres L.

• Faculte de Medicine, Aix-Marseille Universite, Campus Nord, Marseille, France

autor

Ankiri N.

• Faculte de Medicine, Aix-Marseille Universite, Campus Nord, Marseille, France

autor

Carlier E.

• Faculte de Medicine, Aix-Marseille Universite, Campus Nord, Marseille, France

autor

Debanne D.

• Faculte de Medicine, Aix-Marseille Universite, Campus Nord, Marseille, France

Uwagi

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