Roles of feedback and feed-forward networks of dopamine subsystems: insights fromDrosophilastudies
Year: 2024
Type: preprint
Abstract: Across animal species, dopamine-operated memory systems comprise anatomically segregated, functionally diverse subsystems. Although individual subsystems could operate independently to support distinct types of memory, the logical interplay between subsystems is expected to enable more complex memory processing by allowing existing memory to influence future learning. Recent comprehensive ultrastructural analysis of theDrosophilamushroom body revealed intricate networks interconnecting the dopamine subsystems—the mushroom body compartments. Here, we review the functions of some of these connections that are beginning to be understood. Memory consolidation is mediated by two different forms of network: A recurrent feedback loop within a compartment maintains sustained dopamine activity required for consolidation, whereas feed-forward connections across compartments allow short-term memory formation in one compartment to open the gate for long-term memory formation in another compartment. Extinction and reversal of aversive memory rely on a similar feed-forward circuit motif that signals omission of punishment as a reward, which triggers plasticity that counteracts the original aversive memory trace. Finally, indirect feed-forward connections from a long-term memory compartment to short-term memory compartments mediate higher-order conditioning. Collectively, these emerging studies indicate that feedback control and hierarchical connectivity allow the dopamine subsystems to work cooperatively to support diverse and complex forms of learning.
Source: Learning & Memory
Authors: Andrew M. Davidson, Toshihide Hige
Institution: University of North Carolina at Chapel Hill
Language: English
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: diamond
Funders: National Science Foundation, United States-Israel Binational Science Foundation, National Institutes of Health, Directorate for Biological Sciences, Bio-oriented Technology Research Advancement Institution, National Institute of Mental Health, National Institute on Deafness and Other Communication Disorders
OpenAlex ID: W4403345759