Transient sensorimotor projections in the developmental song learning period

Area of Science:

• Neuroscience
• Developmental Biology
• Bioacoustics

Background:

• Motor skill acquisition relies on memory and guidance.
• Song learning in male zebra finches involves memorizing and matching tutor songs (TS).
• The neural basis for auditory-memory-guided sensorimotor learning is not well understood.

Purpose of the Study:

• To identify the neuroanatomical substrate for auditory-memory-guided sensorimotor learning in songbirds.
• To investigate the role of specific neuronal projections in vocal learning during development.

Main Methods:

• Whole-brain connectome analysis combined with activity-dependent viral expression in juvenile zebra finches.
• Targeted viral induction of cell death in specific neuronal populations.
• Analysis of axonal projection dynamics and their correlation with song learning.

Main Results:

• Identified transient projections from TS-responsive neurons in the NCM to the HVC motor region in juveniles.
• Selective elimination of these juvenile NCM neurons impaired song learning.
• Axonal pruning from NCM to HVC occurred independently of sensory learning period closure.

Conclusions:

• Dynamic axonal pruning of NCM projections to HVC regulates auditory-memory-guided vocal learning.
• This mechanism ensures timely song acquisition during a critical developmental window.
• Highlights the importance of transient neural connections in developmental learning processes.