English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Calcium ions (Ca 2+ ) are essential for many cellular signaling mechanisms and enter the cytosol mostly through voltage-gated calcium channels. Here, using high-speed Ca 2+  imaging up to 20 kHz in the rat layer five pyramidal neuron axon we found that activity-dependent intracellular calcium concentration ([Ca 2+ ] i ) in the axonal initial segment was only partially dependent on voltage-gated calcium channels. Instead, [Ca 2+ ] i  changes were sensitive to the specific voltage-gated sodium (Na V ) channel blocker tetrodotoxin. Consistent with the conjecture that Ca 2+  enters through the Na V  channel pore, the optically resolved  I  Ca  in the axon initial segment overlapped with the activation kinetics of Na V  channels and heterologous expression of Na V 1.2 in HEK-293 cells revealed a tetrodotoxin-sensitive [Ca 2+ ] i  rise. Finally, computational simulations predicted that axonal [Ca 2+ ] i  transients reflect a 0.4% Ca 2+  conductivity of Na V  channels. The findings indicate that Ca 2+  permeation through Na V  channels provides a submillisecond rapid entry route in Na V -enriched domains of mammalian axons.

Ca 2+ entry through Na V channels generates submillisecond axonal Ca 2+ signaling