[]Title: Striatal dopamine integrates cost, benefit and motivation

[]Authors: Neir Eshel, Gavin C. Touponse, Allan R. Wang, Amber K. Osterman, Amei N.

Shank, Alexandra M. Groomm, Lara Taniguchi, Daniel F. Cardozo Pinto, Jason

Tucciarone, Brandon S. Bentzley, Robert C. Malenka

[]Journal/Year: bioRxiv (2022)

[]DOI: 10.1101/2022.09.20.508777

[]Key Findings: the dopamine (DA) release in nucleus accumbens (NAc) and dorsolateral striatum (DLS) encoded both the reward benefit and behavioral cost, in a positive manner. However, it encoded the behavioral motivation, in a negative manner.

[]Conclusion: the DA release in striatum could encode reward benefit, behavioral cost, and motivational level.

[]Comments: this study perfectly shown the essentials of scientific methods: controlling single variable. In daily life, it's difficult to draw a solid conclusion under most situations because multiple variables are always interwinded, making it almost impossible to establish a clear relationship between each variable and the final concequences. To figure out a clear cause-effect relationship, we need to change one variable at a time and make other variables unchanged. Only in this, we can confidently outline the relationship between each variable and the integrated final results.

In this study, the authors tried to disentangle three variables: reward benefit, cost, and motivation. Previous studies had reported controversial observations: some reported that the DA release in striatum only encoded reward benefit; others believed that it mainly encoded behavioral cost; and motivation was always indistinguishable with reward benefit in many previous studies. So it's still under debate about the functions of DA in striatum. To solve the debate, the authors designed multiple behavioral tests and changed only one variable each time. In this way, they clearly shown that the DA in striatum could encode all of the three variables: benefit, cost, and motivation, but in two disparate ways.

[]Writing Date: 2023-04-11