Dopaminergic inputs in the dentate gyrus direct the choice of memory encoding

Journal Article · Tue Sep 13 04:00:00 UTC 2016 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.1606951113 · OSTI ID:1328121

Du, Huiyun ^[1]; Deng, Wei ^[2]; Aimone, James B. ^[3]; Ge, Minyan ^[1]; Parylak, Sarah ^[2]; Walch, Keenan ^[2]; Zhang, Wei ^[4]; Cook, Jonathan ^[2]; Song, Huina ^[1]; Wang, Liping ^[4]; Gage, Fred H. ^[2]; Mu, Yangling ^[1]

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1. Huazhong Univ. of Science and Technology, Wuhan (China)
2. Salk Institute for Biological Studies, La Jolla, CA (United States)
3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
4. Chinese Academy of Sciences, Shenzhen (China)

Rewarding experiences are often well remembered, and such memory formation is known to be dependent on dopamine modulation of the neural substrates engaged in learning and memory; however, it is unknown how and where in the brain dopamine signals bias episodic memory toward preceding rather than subsequent events. Here we found that photostimulation of channelrhodopsin-2–expressing dopaminergic fibers in the dentate gyrus induced a long-term depression of cortical inputs, diminished theta oscillations, and impaired subsequent contextual learning. Computational modeling based on this dopamine modulation indicated an asymmetric association of events occurring before and after reward in memory tasks. In subsequent behavioral experiments, preexposure to a natural reward suppressed hippocampus-dependent memory formation, with an effective time window consistent with the duration of dopamine-induced changes of dentate activity. Altogether, our results suggest a mechanism by which dopamine enables the hippocampus to encode memory with reduced interference from subsequent experience.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1328121
• Report Number(s): SAND--2016-7558J; 646387
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 37 Vol. 113; ISSN 0027-8424
• Publisher: National Academy of Sciences, Washington, DC (United States)Copyright Statement
• Country of Publication: United States
• Language: English