Sodium channel endocytosis drives axon initial segment plasticity.

Activity-dependent plasticity of the axon initial segment (AIS) endows neurons with the ability to adapt action potential output to changes in network activity. Action potential initiation at the AIS highly depends on the clustering of voltage-gated sodium channels, but the molecular mechanisms regulating their plasticity remain largely unknown. Here, we developed genetic tools to label endogenous sodium channels and their scaffolding protein, to reveal their nanoscale organization and longitudinally image AIS plasticity in hippocampal neurons in slices and primary cultures. We find that N-methyl-d-aspartate receptor activation causes both long-term synaptic depression and rapid internalization of AIS sodium channels within minutes. The clathrin-mediated endocytosis of sodium channels at the distal AIS increases the threshold for action potential generation. These data reveal a fundamental mechanism for rapid activity-dependent AIS reorganization and suggests that plasticity of intrinsic excitability shares conserved features with synaptic plasticity.

Citation

Amélie Fréal, Nora Jamann, Jolijn Ten Bos, Jacqueline Jansen, Naomi Petersen, Thijmen Ligthart, Casper C Hoogenraad, Maarten H P Kole. Sodium channel endocytosis drives axon initial segment plasticity. Science advances. 2023 Sep 15;9(37):eadf3885

Mesh Tags

Substances

PMID: 37713493

search → result