Activity-Dependent Plasticity of Axo-axonic Synapses at the Axon Initial Segment

TY - JOUR

T1 - Activity-Dependent Plasticity of Axo-axonic Synapses at the Axon Initial Segment

AU - Pan-Vazquez, Alejandro

AU - Wefelmeyer, Winnie

AU - Gonzalez Sabater, Victoria

AU - Neves, Guilherme

AU - Burrone, Juan

N1 - Copyright © 2020. Published by Elsevier Inc.

PY - 2020/4/22

Y1 - 2020/4/22

N2 - The activity-dependent rules that govern the wiring of GABAergic interneurons are not well understood. Chandelier cells (ChCs) are a type of GABAergic interneuron that control pyramidal cell output through axo-axonic synapses that target the axon initial segment. In vivo imaging of ChCs during development uncovered a narrow window (P12-P18) over which axons arborized and formed connections. We found that increases in the activity of either pyramidal cells or individual ChCs during this temporal window result in a reversible decrease in axo-axonic connections. Voltage imaging of GABAergic transmission at the axon initial segment (AIS) showed that axo-axonic synapses were depolarizing during this period. Identical manipulations of network activity in older mice (P40-P46), when ChC synapses are inhibitory, resulted instead in an increase in axo-axonic synapses. We propose that the direction of ChC synaptic plasticity follows homeostatic rules that depend on the polarity of axo-axonic synapses.

AB - The activity-dependent rules that govern the wiring of GABAergic interneurons are not well understood. Chandelier cells (ChCs) are a type of GABAergic interneuron that control pyramidal cell output through axo-axonic synapses that target the axon initial segment. In vivo imaging of ChCs during development uncovered a narrow window (P12-P18) over which axons arborized and formed connections. We found that increases in the activity of either pyramidal cells or individual ChCs during this temporal window result in a reversible decrease in axo-axonic connections. Voltage imaging of GABAergic transmission at the axon initial segment (AIS) showed that axo-axonic synapses were depolarizing during this period. Identical manipulations of network activity in older mice (P40-P46), when ChC synapses are inhibitory, resulted instead in an increase in axo-axonic synapses. We propose that the direction of ChC synaptic plasticity follows homeostatic rules that depend on the polarity of axo-axonic synapses.

KW - Chandelier

KW - GABA

KW - activity-dependent

KW - axo-axonic

KW - axon initial segment

KW - development

KW - homeostatic

KW - interneuron

KW - plasticity

UR - https://www.scopus.com/pages/publications/85082756410

U2 - 10.1016/j.neuron.2020.01.037

DO - 10.1016/j.neuron.2020.01.037

M3 - Article

C2 - 32109363

SN - 0896-6273

VL - 106

SP - 265-276.e6

JO - Neuron

JF - Neuron

IS - 2

ER -