BTBD3 controls dendrite orientation toward active axons in mammalian neocortex

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• Experience-dependent structural plasticity is crucial for forming functional neural circuits.
• Understanding the molecular mechanisms guiding neuronal development is essential for neuroscience research.

Purpose of the Study:

• To investigate the role of BTB/POZ domain-containing 3 (BTBD3) in controlling dendritic field orientation during sensory cortex development.
• To elucidate how neuronal activity influences dendritic structure and circuit formation.

Main Methods:

• Studied developing mouse somatosensory cortex.
• Observed endogenous Btbd3 localization in response to neuronal activity.
• Examined dendritic orientation using ectopic expression in mouse visual cortex and natural expression in ferret visual cortex.

Main Results:

• Endogenous Btbd3 translocated to the nucleus in response to neuronal activity in developing mouse somatosensory cortex.
• Btbd3 oriented primary dendrites toward active axons within the barrel hollow.
• Ectopic and natural expression of BTBD3 in visual cortex also directed dendrites toward active axon terminals.

Conclusions:

• BTBD3 acts as a key regulator of dendritic field orientation during sensory cortex development.
• The mechanism of BTBD3-mediated dendrite orientation is conserved across different cortical areas and species.
• This process highlights how tuning subcellular polarity to high sensory activity sources contributes to high-acuity sensory function.