Abstract
Dentate gyrus adult neurogenesis is implicated in the formation of hippocampal-dependent contextual associations. However, the role of adult neurogenesis during reward-based context-dependent paradigms—such as conditioned place preference (CPP)—is understudied. Therefore, we used image-guided, hippocampal-targeted X-ray irradiation (IG-IR) and morphine CPP to explore whether dentate gyrus adult neurogenesis plays a role in reward memories created in adult C57BL/6J male mice. In addition, as adult neurogenesis appears to participate to a greater extent in retrieval and extinction of recent (<48 hr posttraining) versus remote (>1 week posttraining) memories, we specifically examined the role of adult neurogenesis in reward-associated contextual memories probed at recent and remote timepoints. Six weeks post-IG-IR or Sham treatment, mice underwent morphine CPP. Using separate groups, retrieval of recent and remote reward memories was found to be similar between IG-IR and Sham treatments. Interestingly, IG-IR mice showed impaired extinction—or increased persistence—of the morphine-associated reward memory when it was probed 24-hr (recent) but not 3-weeks (remote) postconditioning relative to Sham mice. Taken together, these data show that hippocampal-directed irradiation and the associated decrease in dentate gyrus adult neurogenesis affect the persistence of recently—but not remotely—probed reward memory. These data indicate a novel role for adult neurogenesis in reward-based memories and particularly the extinction rate of these memories. Consideration of this work may lead to better understanding of extinction-based behavioral interventions for psychiatric conditions characterized by dysregulated reward processing.
Original language | English (US) |
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Pages (from-to) | 726-735 |
Number of pages | 10 |
Journal | Hippocampus |
Volume | 29 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2019 |
Keywords
- addiction
- conditioned place preference
- learning and memory
- opiate
- retrieval
ASJC Scopus subject areas
- Cognitive Neuroscience