A genetically defined tecto-thalamic pathway drives a system of superior-colliculus-dependent visual cortices

Area of Science:

• Neuroscience
• Visual Processing
• Sensory Systems

Background:

• The geniculo-striate pathway is traditionally considered the primary route for visual information to the cortex.
• Recent studies suggest the postrhinal cortex (POR) relies on the tecto-thalamic pathway via the superior colliculus (SC).

Purpose of the Study:

• To investigate if a broader system of tecto-thalamic cortical visual areas exists.
• To determine the type of visual information processed by this pathway.
• To explore the role of SC-dependent cortices in visual perception.

Main Methods:

• Utilized mouse models to study visual responses in cortical areas.
• Investigated SC-dependence of visual responses across different cortical regions.
• Examined genetically defined cell types connecting the SC to the pulvinar thalamic nucleus.
• Assessed the ability of SC-dependent cortices to differentiate visual motion stimuli.

Main Results:

• Identified multiple mouse cortical areas with visual responses dependent on the SC.
• Observed the strongest SC-dependence in the most lateral visual areas.
• Demonstrated that this system is driven by a specific SC-to-pulvinar cell type.
• Showed that SC-dependent cortices can distinguish self-generated from externally generated visual motion.

Conclusions:

• Lateral visual areas form a system reliant on the tecto-thalamic pathway.
• This system plays a role in processing visual motion, particularly in the context of self-motion.
• Challenges traditional views of visual cortical processing and highlights alternative pathways for visual information.