Bi-directional Control of Synaptic Input Summation and Spike Generation by GABAergic Inputs at the Axon Initial Segment / 神经科学通报·英文版
Neuroscience Bulletin
;
(6): 1-13, 2023.
Article
in English
| WPRIM
| ID: wpr-971533
ABSTRACT
Differing from other subtypes of inhibitory interneuron, chandelier or axo-axonic cells form depolarizing GABAergic synapses exclusively onto the axon initial segment (AIS) of targeted pyramidal cells (PCs). However, the debate whether these AIS-GABAergic inputs produce excitation or inhibition in neuronal processing is not resolved. Using realistic NEURON modeling and electrophysiological recording of cortical layer-5 PCs, we quantitatively demonstrate that the onset-timing of AIS-GABAergic input, relative to dendritic excitatory glutamatergic inputs, determines its bi-directional regulation of the efficacy of synaptic integration and spike generation in a PC. More specifically, AIS-GABAergic inputs promote the boosting effect of voltage-activated Na+ channels on summed synaptic excitation when they precede glutamatergic inputs by >15 ms, while for nearly concurrent excitatory inputs, they primarily produce a shunting inhibition at the AIS. Thus, our findings offer an integrative mechanism by which AIS-targeting interneurons exert sophisticated regulation of the input-output function in targeted PCs.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Axons
/
Synapses
/
Action Potentials
/
Pyramidal Cells
/
Axon Initial Segment
/
Interneurons
/
Neurons
Language:
English
Journal:
Neuroscience Bulletin
Year:
2023
Type:
Article
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