Previous studies of the retrosplenial cortex (RSC) have focused on its role in navigation and memory, consistent with its well-established medial temporal connections, but recent evidence also suggests a role for this region in reward and decision making. Because function is determined largely by anatomical connections, and to better understand the anatomy of RSC, we used tract-tracing methods to examine the anatomical connectivity between the rat RSC and frontostriatal networks (canonical reward and decision-making circuits). We find that, among frontal cortical regions, RSC bidirectionally connects most strongly with the ACC, but also with an area of the central-medial orbito-frontal cortex. RSC projects to the dorsomedial striatum, and its terminal fields are virtually encompassed by the frontal-striatal projection zone, suggestive of functional convergence through the basal ganglia. This overlap is driven by ACC, prelimbic cortex, and orbito-frontal cortex, all of which contribute to goal-directed decision making, suggesting that the RSC is involved in similar processes.
Bibliographical noteFunding Information:
National Institute of Mental Health (http://dx.doi.org/10 .13039/100000025), grant number: R01118257. Brain and Behavior Research Foundation (http://dx.doi.org/10 .13039/100000874), grant number: NARSAD Young Investigator Award. MnDrive Brain Conditions Initiative.
We thank Tanya Casta, Adriana Cushnie, Mark Grier, and Anish Sethi for assistance with data collection. This work was supported by the National Institute of Mental Health (R01118257), the MnDrive Brain Conditions Initiative, and the Brain & Behavior Research Foundation.
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