Collicular circuits for flexible sensorimotor routing

Duan et al. reveal circuit mechanisms of executive control in the midbrain superior colliculus (SC), where response inhibition and context-based vector inversion are instantiated by specific SC subpopulations. Context-based sensorimotor routing is a hallmark of executive control. Pharmacological inactivations in rats have implicated the midbrain superior colliculus (SC) in this process. But what specific role is this, and what circuit mechanisms support it? Here we report a subset of rat SC neurons that instantiate a specific link between the representations of context and motor choice. Moreover, these neurons encode animals' choice far earlier than other neurons in the SC or in the frontal cortex, suggesting that their neural dynamics lead choice computation. Optogenetic inactivations revealed that SC activity during context encoding is necessary for choice behavior, even while that choice behavior is robust to inactivations during choice formation. Searches for SC circuit models matching our experimental results identified key circuit predictions while revealing some a priori expected features as unnecessary. Our results reveal circuit mechanisms within the SC that implement response inhibition and context-based vector inversion during executive control.

Automated summary

The study uncovers circuit mechanisms within the superior colliculus (SC) of the midbrain that implement response inhibition and context-based vector inversion during executive control. This subset of neural activity in the SC plays a crucial role in linking context and motor choice representations in rats.