Context value updating and multidimensional neuronal encoding in the retrosplenial cortex

The retrosplenial cortex (RSC) has diverse functional inputs and is engaged by various sensory, spatial, and associative learning tasks. We examine how multiple functional aspects are integrated on the single-cell level in the RSC and how the encoding of task-related parameters changes across learning. Using a visuospatial context discrimination paradigm and two-photon calcium imaging in behaving mice, a large proportion of dysgranular RSC neurons was found to encode multiple task-related dimensions while forming context-value associations across learning. During reversal learning requiring increased cognitive flexibility, we revealed an increased proportion of multidimensional encoding neurons that showed higher decoding accuracy for behaviorally relevant context-value associations. Chemogenetic inactivation of RSC led to decreased behavioral context discrimination during learning phases in which context-value associations were formed, while recall of previously formed associations remained intact. RSC inactivation resulted in a persistent positive behavioral bias in valuing contexts, indicating a role for the RSC in context-value updating. Goal-directed behaviors require the brain to integrate information across many task-related dimensions. Here, the authors use a virtual context discrimination paradigm in mice to demonstrate the capacity for neurons in the retrosplenial cortex to exhibit multidimensional encoding across learning.

Automated summary

The study demonstrates that neurons in the retrosplenial cortex are capable of encoding multiple task-related dimensions across learning, particularly showing enhanced performance in tasks requiring cognitive flexibility. Chemogenetic inactivation of the RSC disrupts behavioral context discrimination during learning phases, but does not affect recall of previously formed associations, suggesting a crucial role for the RSC in context-value updating.