Multiple periods of functional ocular dominance plasticity in mouse visual cortex

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Visual System Plasticity

Background:

• The exact timing of when experience influences neural circuit development in the mouse visual system remains unclear.
• Understanding critical periods for neural plasticity is crucial for comprehending brain development and function.

Purpose of the Study:

• To investigate the temporal dynamics of neural circuit plasticity in the mouse visual cortex.
• To determine the precise developmental windows during which experience, specifically visual input, shapes ocular dominance (OD).

Main Methods:

• Utilized Arc induction as a marker to monitor the functional representation of the ipsilateral eye in the cortex.
• Implemented monocular deprivation during different developmental stages (before, during, and after the critical period).
• Examined changes in ocular dominance (OD) shifts within the visual cortex, including layer 4 and layer 6.

Main Results:

• Arc induction accurately reflected ocular dominance (OD) shifts in the binocular zone following monocular deprivation during the critical period.
• OD shifts favoring the open eye and weakening of the deprived eye were observed in layer 4 both before and after the critical period.
• Unexpectedly, these OD shifts extended into the monocular zone, indicating broader plasticity than anticipated.
• Layer 6 in adult mice did not exhibit this plasticity.

Conclusions:

• Functional ocular dominance (OD) in the cortex can be modified by visual experience significantly earlier and later than the established critical period.
• Neural plasticity in the visual cortex extends beyond traditional critical periods, with layer-specific differences in responsiveness to visual input.
• These findings challenge conventional views of critical periods and highlight a broader window for experience-dependent visual cortex development.