Spatial representations in the superior colliculus are modulated by competition among targets

Area of Science:

• Neuroscience
• Behavioral Biology
• Computational Neuroscience

Background:

• Goal-directed behaviors rely on selecting and moving to spatial targets.
• The superior colliculus (SC) is hypothesized to contain a spatial map influencing movement decisions.
• Existing evidence suggests SC spatial representations are modulated by decision-making variables.

Purpose of the Study:

• To investigate if superior colliculus (SC) spatial representations arise from competitive target selection.
• To differentiate neural mechanisms underlying movement selection in competitive versus non-competitive contexts.
• To explore the role of the SC in resolving spatial choices.

Main Methods:

• Recorded neural activity in the superior colliculus (SC) of mice during a spatial target selection task.
• Compared SC activity in 'competitive' trials (ambiguous target reward) versus 'non-competitive' trials (consistent target reward).
• Utilized unilateral optogenetic inactivation of SC activity to assess its causal role in target selection.

Main Results:

• In competitive trials, SC activity predicted contralateral target movements.
• In non-competitive trials, SC neurons showed reduced spatial selectivity or predicted ipsilateral movements.
• SC inactivation biased choices in competitive but not non-competitive trials, confirming its role in selection.

Conclusions:

• Superior colliculus (SC) activity is crucial for selecting among competing spatial targets.
• Distinct neural pathways govern movement selection under competitive and non-competitive conditions.
• The SC plays a specific role in resolving spatial choices when multiple targets are available.