Abstract
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.
Original language | English |
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Pages (from-to) | 265-276.e6 |
Journal | Neuron |
Volume | 106 |
Issue number | 2 |
Early online date | 10 Feb 2020 |
DOIs | |
Publication status | Published - 22 Apr 2020 |
Keywords
- Chandelier
- GABA
- activity-dependent
- axo-axonic
- axon initial segment
- development
- homeostatic
- interneuron
- plasticity