Translaminar synchronous neuronal activity is required for columnar synaptic strengthening in the mouse neocortex
Translaminar synchronous neuronal activity is required for columnar synaptic strengthening in the mouse neocortex

Translaminar synchronous neuronal activity is required for columnar synaptic strengthening in the mouse neocortex

Nat Commun. 2025 Feb 3;16(1):1296. doi: 10.1038/s41467-024-55783-w.

ABSTRACT

Synchronous neuronal activity is a hallmark of the developing mouse primary somatosensory cortex. While the patterns of synchronous neuronal activity in cortical layer 2/3 have been well described, the source of the robust layer 2/3 activity is still unknown. Using a novel microprism preparation and in vivo 2-photon imaging in neonatal mice, we show that synchronous neuronal activity is organized in barrel columns across layers. Monosynaptic rabies tracing and slice electrophysiology experiments reveal that layer 2/3 pyramidal neurons receive significant layer 5 inputs during the first postnatal week, and silencing layer 5 synaptic outputs results in a significant reduction in spontaneous activity, abnormal sensory-evoked activity and disrupted layer 4-layer 2/3 connectivity. Our results demonstrate that translaminar layer 5-layer 2/3 connectivity plays an important role in synchronizing the developing barrel column to ensure the strengthening of layer 4-layer 2/3 connections, supporting the formation of the canonical cortical organization in barrel cortex.

PMID:39900899 | DOI:10.1038/s41467-024-55783-w