Cortical feedback modulates distinct critical period development in mouse visual thalamus

Area of Science:

• Neuroscience
• Developmental Biology
• Visual System Research

Background:

• Ocular dominance (OD) plasticity in the primary visual cortex (V1) is crucial for visual development.
• Recent findings suggest similar OD plasticity occurs in the dorsal lateral geniculate nucleus (dLGN).
• The precise timing and neural circuit mechanisms of dLGN plasticity remain largely unknown.

Purpose of the Study:

• To define the critical period for OD plasticity in the mouse dLGN.
• To investigate the role of neural circuits, particularly V1, in dLGN OD plasticity.
• To understand the developmental trajectory of OD bias in dLGN binocular neurons.

Main Methods:

• Utilized in vivo electrophysiology in mice.
• Manipulated visual cortex (V1) activity using pharmacological agents (muscimol, N-methyl-D-aspartate).
• Assessed ocular dominance bias and plasticity in dLGN binocular neurons.

Main Results:

• Established the critical period for dLGN OD plasticity from eye opening to puberty.
• Observed an innate OD formation process in dLGN neurons, shifting from contralateral to equal bias.
• Found that V1 inactivation differentially affected dLGN development and plasticity: instant inactivation had no effect, short-term reversal occurred, and long-term inactivation caused immaturity.

Conclusions:

• The dLGN exhibits a distinct critical period for OD plasticity, influenced by visual experience.
• V1 plays a significant role in modulating dLGN OD plasticity and development.
• Understanding dLGN plasticity offers insights into visual system development and potential therapeutic targets.