# Neuronal Activity Promotes Node‐Like Cluster Assembly Prior to Myelination and Remyelination in the Central Nervous System

## TL;DR

Neuronal activity helps form node-like clusters before myelination, which may influence how nerves communicate and repair.

## Contribution

The study reveals that neuronal activity regulates node-like cluster formation through Nav1.1, a key step in activity-driven myelination.

## Key findings

- Neuronal activity promotes node-like cluster assembly before myelination and remyelination.
- Nav1.1 is essential for node-like cluster formation and is regulated by neuronal activity.
- Node-like clusters may serve as intermediates in shaping myelin patterns during development and repair.

## Abstract

In recent years, myelination has been recognized as a key process in neural plasticity and network refinement, in addition to its role in axonal conduction and neuronal metabolic support. The fast saltatory conduction along myelinated fibers relies on the nodes of Ranvier. Node‐like clusters can form prior to myelin deposition in development and repair and can regulate axonal conduction, myelin deposition initiation, as well as contribute to the formation of mature nodes of Ranvier. In this study, we show that node‐like cluster assembly is modulated by neuronal activity and could thus be an intermediate step in activity‐induced (re)myelination. We further identify the regulation of Nav1.1 expression, which we show to be required for node‐like cluster formation, as part of the molecular mechanism implicated in the activity‐dependent regulation of node‐like cluster assembly. This process may serve in shaping neuronal networks and myelin patterns during development, plasticity and repair.

Ronzano et al. show that neuronal activity promotes node‐like cluster (NLC) formation before (re)myelination by regulating β1Nav and Nav1.1, which are essential for NLC assembly. This may represent an intermediate step in activity‐driven myelination and contribute to the regulation of axonal conduction.