A postnatal critical period for orientation plasticity in the cat visual cortex

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Visual System Research

Background:

• Orientation selectivity in the visual cortex is crucial for shape perception.
• The developmental timeline and experience-dependent changes in this selectivity remain largely unknown.

Purpose of the Study:

• To investigate the temporal profile of orientation plasticity in the kitten visual cortex.
• To understand how visual experience modifies orientation selectivity during early development.

Main Methods:

• Kittens were reared with goggles exposing them to a single orientation.
• Orientation maps were analyzed after different durations and starting ages of goggle rearing (GR).
• N-methyl-D-aspartate receptor (NMDAR) antagonist was used to probe plasticity mechanisms.

Main Results:

• Goggle rearing (GR) between postnatal days 16-30 led to over-representation of the exposed orientation.
• Extended GR consolidated these changes, while later GR (after P50) resulted in under-representation.
• NMDAR antagonist significantly suppressed plasticity during the most sensitive period.

Conclusions:

• A specific postnatal sensitive period exists for orientation selectivity modification.
• The visual cortex dynamically regulates orientation plasticity and map consolidation based on visual experience.
• NMDARs play a critical role in mediating orientation plasticity during this sensitive period.