RBFOX3/NeuN is dispensable for visual function.

Area of Science:

• Neuroscience
• Molecular Biology
• Ophthalmology

Background:

• RBFOX3/NeuN is a key regulator of neuronal splicing, impacting neural circuitry, neurogenesis, and synaptogenesis.
• While RBFOX3 is expressed in neurons, its specific role in the retina, particularly in ganglion and inner nuclear layers, remains largely unknown.
• RBFOX3 knockout mice show visual learning deficits, highlighting the need to understand RBFOX3's retinal function.

Purpose of the Study:

• To investigate the role of RBFOX3 in retinal development and function.
• To determine the specific retinal cell types expressing RBFOX3.
• To assess the impact of RBFOX3 deletion on retinal structure and visual performance.

Main Methods:

• Analysis of RBFOX3 expression during retinal development.
• Immunohistochemistry to identify RBFOX3-expressing cells in retinal layers.
• Assessment of retinal structure and cell counts in RBFOX3 knockout mice.
• Evaluation of visual functions, including image-forming and non-image-forming processes.

Main Results:

• RBFOX3 expression is developmentally regulated in the retina, primarily in ganglion, amacrine, and horizontal cells.
• Deletion of RBFOX3 leads to a reduced thickness of the inner plexiform layer, where synaptic connections are formed.
• The number of retinal ganglion and amacrine cells remains normal in RBFOX3 knockout mice.
• Retinal ganglion cell innervation to brain targets and overall visual functions are unaffected by RBFOX3 loss.

Conclusions:

• RBFOX3 plays a role in regulating retinal structure, specifically the inner plexiform layer.
• Despite structural changes, RBFOX3 is not essential for the normal development of retinal cell populations or overall visual function.
• RBFOX3 is dispensable for visual function, suggesting other factors compensate for its absence in the visual system.