Severe deficiency of the voltage-gated sodium channel Na V 1.2 elevates neuronal excitability in adult mice.
Document Type
Article
Publication Date
8-3-2021
Publication Title
Cell Rep
Keywords
JGM
JAX Source
Cell Rep 2021 Aug 3; 36(5):109495
Volume
36
Issue
5
First Page
109495
Last Page
109495
ISSN
2211-1247
PMID
34348148
DOI
https://doi.org/10.1016/j.celrep.2021.109495
Abstract
Scn2a encodes the voltage-gated sodium channel NaV1.2, a main mediator of neuronal action potential firing. The current paradigm suggests that NaV1.2 gain-of-function variants enhance neuronal excitability, resulting in epilepsy, whereas NaV1.2 deficiency impairs neuronal excitability, contributing to autism. However, this paradigm does not explain why ∼20%-30% of individuals with NaV1.2 deficiency still develop seizures. Here, we report the counterintuitive finding that severe NaV1.2 deficiency results in increased neuronal excitability. Using a NaV1.2-deficient mouse model, we show enhanced intrinsic excitability of principal neurons in the prefrontal cortex and striatum, brain regions known to be involved in Scn2a-related seizures. This increased excitability is autonomous and reversible by genetic restoration of Scn2a expression in adult mice. RNA sequencing reveals downregulation of multiple potassium channels, including KV1.1. Correspondingly, KV channel openers alleviate the hyperexcitability of NaV1.2-deficient neurons. This unexpected neuronal hyperexcitability may serve as a cellular basis underlying NaV1.2 deficiency-related seizures.
Recommended Citation
Zhang J,
Chen X,
Eaton M,
Wu J,
Ma Z,
Lai S,
Park A,
Ahmad T,
Que Z,
Lee J,
Xiao T,
Li Y,
Wang Y,
Olivero-Acosta M,
Schaber J,
Jayant K,
Yuan C,
Huang Z,
Lanman N,
Skarnes W,
Yang Y.
Severe deficiency of the voltage-gated sodium channel Na V 1.2 elevates neuronal excitability in adult mice. Cell Rep 2021 Aug 3; 36(5):109495