Coherent cortical representations develop after experience via feedforward-recurrent circuit alignment

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Sensory cortical areas transform stimulus input into selective responses.
• Layer 4 (L4) neurons connect to Layer 2/3 (L2/3) modules, critical for response amplification.
• The developmental process of feedforward-recurrent interaction alignment is not well understood.

Purpose of the Study:

• Investigate the development of feedforward-recurrent interactions in sensory cortex.
• Determine how experience shapes neural selectivity and response reliability.
• Identify mechanisms underlying the formation of precise sensory representations.

Main Methods:

• Simultaneous electrophysiology and calcium imaging in visually naïve and experienced animals.
• Computational modeling of feedforward-recurrent interactions.
• Whole-cell recordings to analyze subthreshold responses and orientation tuning.

Main Results:

• Naïve animals show less precise orientation tuning in L4-L2/3 interactions compared to experienced animals.
• High response variability in naïve L4 neurons decreases with experience.
• Evidence of feedforward-recurrent misalignment in naïve animals, characterized by dynamic L2/3 tuning shifts.

Conclusions:

• Visual experience is critical for realigning feedforward-recurrent interactions in the cortex.
• This realignment leads to reliable sensory representations with interlaminar temporal coherence.
• The study elucidates a key developmental mechanism for sensory processing.