A Comparison of Dopaminergic and Cholinergic Populations Reveals Unique Contributions of VTA Dopamine Neurons to Short-Term Memory

• Main Authors: Jung Yoon Choi, Hee Jae Jang, Sharon Ornelas, Weston T. Fleming, Daniel Fürth, Jennifer Au, Akhil Bandi, Esteban A. Engel, Ilana B. Witten
• Format: Article
• Language: English
• Published: Elsevier 2020-12-01
• Series: Cell Reports
• Subjects: dopamine; acetylcholine; VTA; SNc; Nucleus basalis; Medial septum
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211124720314819

Summary: We systematically compare the contributions of two dopaminergic and two cholinergic ascending populations to a spatial short-term memory task in rats. In ventral tegmental area dopamine (VTA-DA) and nucleus basalis cholinergic (NB-ChAT) populations, trial-by-trial fluctuations in activity during the delay period relate to performance with an inverted-U, despite the fact that both populations have low activity during that time. Transient manipulations reveal that only VTA-DA neurons, and not the other three populations we examine, contribute causally and selectively to short-term memory. This contribution is most significant during the delay period, when both increases and decreases in VTA-DA activity impair short-term memory. Our results reveal a surprising dissociation between when VTA-DA neurons are most active and when they have the biggest causal contribution to short-term memory, and they also provide support for classic ideas about an inverted-U relationship between neuromodulation and cognition.