UC San Diego

The retrosplenial cortex (RSC) is a unique brain structure that forms what is widely considered a hub of neuronal connections and interactions in the brain. Previous studies have implicated the RSC in contextual processing and discrimination, spatial memory, and learning (Keene & Bucci, 2008a; Keene & Bucci, 2008b; Smith et al., 2012; van Groen et al., 2004). Sill, the functions of the retrosplenial cortex in spatial working memory are not very well understood. Here, we investigate the contributions of the RSC to performance on a challenging spatial working memory task via chemogenetic inhibition of RSC neurons. Using this approach, we transiently silenced neurons of the RSC while animals underwent testing on the Triple-T (TTT) maze in multiple task variations. The nature of the TTT maze allows for the expansion of an already complex task, presenting the animals with a uniquely challenging spatial working memory task. Ultimately, we found that inactivation of RSC neurons resulted in a moderate impairment in task performance on the TTT maze, with the most robust effect occurring on the most challenging and recently learned version of the task. Ultimately, these findings suggest that the RSC contributes to performance on a challenging spatial working memory task and may be particularly important for performance on recently learned navigational tasks.