Causal evidence for retina-dependent and -independent visual motion computations in mouse cortex

Area of Science:

• Neuroscience
• Computational Neuroscience
• Sensory Processing

Background:

• The contribution of sensory periphery computations to cortical processing remains unclear.
• Understanding visual motion processing in the retina and visual cortex is crucial for deciphering neural computation.

Purpose of the Study:

• To investigate how retinal computations influence visual motion processing in the primary visual cortex (V1).
• To differentiate between sensory-periphery-dependent and -independent visual motion computations in the cortex.

Main Methods:

• Examined visual motion processing in mice by disrupting retinal direction selectivity.
• Utilized FRMD7 mutants to disrupt horizontal-axis direction selectivity and ablated starburst amacrine cells for complete disruption.
• Monitored neuronal activity in V1 layer 2/3 in response to visual motion stimuli.

Main Results:

• Control mice showed an over-representation of cortical cells preferring posterior visual motion.
• Disruption of retinal direction selectivity abolished this posterior motion preference in V1.
• Cortical responses to higher stimulus speeds were reduced when retinal direction selectivity was impaired.

Conclusions:

• Reveals two distinct visual motion computation pathways in the cortex: one dependent on retinal input and another independent of it.
• Highlights the significant role of retinal direction selectivity in shaping cortical representations of visual motion.
• Provides insights into the hierarchical processing of sensory information from the periphery to the cortex.