Changes in the Dopaminergic circuitry and Adult Neurogenesis linked to Reinforcement Learning in Corvids

Abstract

AbstractThe caudolateral nidopallium (NCL, an analogue of the prefrontal cortex) is known to be involved in learning, memory, and discrimination in crows, whereas the involvement of other brain regions in these phenomena are unknown. However, recent studies on pigeons have demonstrated that besides NCL, basal ganglia-thalamocortical loops connected to this region play are also crucial for learning. The present study demonstrates that besides NCL, other parts of the caudal nidopallium (NC), avian basal ganglia, and intriguingly, vocal control regions in house crows (Corvus splendens), are involved in visual discrimination. We have also found that training on the visual discrimination task can be correlated to neurite pruning in mature dopaminoceptive neurons and immature doublecortin-positive neurons in the NC of house crows. Furthermore, there is an increase in the incorporation of new neurons throughout NC and the medial striatum which can also be linked to learning. For the first time, our results demonstrate that a combination of structural changes in mature and immature neurons and adult neurogenesis are linked to learning in corvids.