Septotemporal variations in hippocampal value and outcome processing

Abstract

A large body of evidence indicates functional variations along the hippocampal longitudinal axis. To investi-gate whether and how value and outcome processing vary between the dorsal (DH) and the ventral hippo -campus (VH), we examined neuronal activity and inactivation effects of the DH and VH in mice performing probabilistic classical conditioning tasks. Inactivation of either structure disrupts value-dependent anticipa-tory licking, and value-coding neurons are found in both structures, indicating their involvement in value pro-cessing. However, the DH neuronal population increases activity as a function of value, while the VH neuronal population is preferentially responsive to the highest-value sensory cue. Also, signals related to outcome -dependent value learning are stronger in the DH. VH neurons instead show rapid responses to punishment and strongly biased responses to negative prediction error. These findings suggest that the DH faithfully rep-resents the external value landscape, whereas the VH preferentially represents behaviorally relevant, salient features of experienced events.