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Karin O, Alon U. The dopamine circuit as a reward-taxis navigation system. PLoS Comput Biol 2022; 18:e1010340. [PMID: 35877694 PMCID: PMC9352198 DOI: 10.1371/journal.pcbi.1010340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 08/04/2022] [Accepted: 06/29/2022] [Indexed: 01/29/2023] Open
Abstract
Studying the brain circuits that control behavior is challenging, since in addition to their structural complexity there are continuous feedback interactions between actions and sensed inputs from the environment. It is therefore important to identify mathematical principles that can be used to develop testable hypotheses. In this study, we use ideas and concepts from systems biology to study the dopamine system, which controls learning, motivation, and movement. Using data from neuronal recordings in behavioral experiments, we developed a mathematical model for dopamine responses and the effect of dopamine on movement. We show that the dopamine system shares core functional analogies with bacterial chemotaxis. Just as chemotaxis robustly climbs chemical attractant gradients, the dopamine circuit performs ‘reward-taxis’ where the attractant is the expected value of reward. The reward-taxis mechanism provides a simple explanation for scale-invariant dopaminergic responses and for matching in free operant settings, and makes testable quantitative predictions. We propose that reward-taxis is a simple and robust navigation strategy that complements other, more goal-directed navigation mechanisms.
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Affiliation(s)
- Omer Karin
- Dept. of Molecular Cell Biology, Weizmann Institute of Science, Rehovot Israel
- Dept. of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Cambridge, United Kingdom
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, United Kingdom
- * E-mail: (OK); (UA)
| | - Uri Alon
- Dept. of Molecular Cell Biology, Weizmann Institute of Science, Rehovot Israel
- * E-mail: (OK); (UA)
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