Extracellular electrophysiology unit data from mouse Superior Colliculus during whisker guided virtual navigation

Spatial awareness is often intentional, arising from deliberate actions towards a target, while at other times it emerges from unexpected motion in the scene. To navigate the environment, animals must differentiate the spatial cues generated by self-motion from object movements that originate externally. To reveal the neural basis of this ability, we examined the midbrain superior colliculus (SC), which contains multiple egocentric maps of sensorimotor space. By simulating whisker-guided navigation through a dynamic landscape, we discovered a transient neural response that selectively emerged for unexpected, externally generated tactile motion. This transient response only emerged when external motion either gained or lost contact with a whisker, arguing that sensorimotor expectations are specific to a somatotopic location. When external motion sustained contact with the same whiskers, neurons shifted their spike timing to follow the dynamics of self-generated tactile features. Thus, representations based on the timing of self-generated cues may surpass the spatial acuity of the whisker array. In conclusion, the SC contains complementary rate and temporal codes to differentiate external from self-generated tactile features.