Cooperative processing of visual threat across collicular pathways

Rapid defensive actions necessitate converting sensory cues into suitable motor responses. The superior colliculus plays a key role in this process, housing specialized cell types that connect visual inputs to various behaviors through parallel output pathways. However, it remains uncertain whether these pathways function independently or in collaboration. To investigate this, researchers employed cell-type-specific inhibition, large-scale electrophysiology, and functional ultrasound imaging.

Inhibiting either narrow-field or wide-field neurons disrupted escape from overhead visual threats, indicating that both pathways are essential for escape. Downstream recordings from targets unveiled a concentrated representation in the more posterior layers of the superior colliculus, which exclusively identified visual stimuli linked to escape.

Conversely, the lateral posterior thalamus exhibited a broader depiction of visual stimuli. The representation of visual threat in the superior colliculus' posterior layers accurately forecasted the onset and intensity of escape in freely moving subjects.

Functional ultrasound imaging across the brain unveiled distinct patterns of activity triggered by visual stimuli that could not be attributed to response magnitude alone or the contribution of individual cell types. Collectively, these findings illustrate a cooperative circuit architecture wherein parallel pathways convey distinct yet complementary signals that collectively facilitate visually driven escape.