| 1. |
- Verharen, J. P. H., et al.
(författare)
-
Dopaminergic contributions to behavioral control under threat of punishment in rats
- 2020
-
Ingår i: Psychopharmacology. - : Springer Science and Business Media LLC. - 0033-3158 .- 1432-2072. ; 237, s. 1769-1782
-
Tidskriftsartikel (refereegranskat)abstract
- Rationale Excessive intake of rewards, such as food and drugs, often has explicit negative consequences, including the development of obesity and addiction, respectively. Thus, choosing not to pursue reward is the result of a cost/benefit decision, proper execution of which requires inhibition of behavior. An extensive body of preclinical and clinical evidence implicates dopamine in certain forms of inhibition of behavior, but it is not fully known how it contributes to behavioral inhibition under threat of explicit punishment. Objectives To assess the involvement of midbrain dopamine neurons and their corticostriatal output regions, the ventral striatum and prefrontal cortex, in control over behavior under threat of explicit (foot shock) punishment in rats. Methods We used a recently developed behavioral inhibition task, which assesses the ability of rats to exert behavioral restraint at the mere sight of food reward, under threat of foot shock punishment. Using in vivo fiber photometry, chemogenetics, c-Fos immunohistochemistry, and behavioral pharmacology, we investigated how dopamine neurons in the ventral tegmental area, as well as its output areas, the ventral striatum and prefrontal cortex, contribute to behavior in this task. Results Using this multidisciplinary approach, we found little evidence for a direct involvement of ascending midbrain dopamine neurons in inhibitory control over behavior under threat of punishment. For example, photometry recordings suggested that VTA DA neurons do not directly govern control over behavior in the task, as no differences were observed in neuronal population activity during successful versus unsuccessful behavioral control. In addition, chemogenetic and pharmacological manipulations of the mesocorticolimbic DA system had little or no effect on the animals' ability to exert inhibitory control over behavior. Rather, the dopamine system appeared to have a role in the motivational components of reward pursuit. Conclusions Together, our data provide insight into the mesocorticolimbic mechanisms behind motivated behaviors by showing a modulatory role of dopamine in the expression of cost/benefit decisions. In contrast to our expectations, dopamine did not appear to directly mediate the type of behavioral control that is tested in our task.
|
|
| 2. |
- Verharen, J. P. H., et al.
(författare)
-
How Reward and Aversion Shape Motivation and Decision Making: A Computational Account
- 2020
-
Ingår i: Neuroscientist. - : SAGE Publications. - 1073-8584. ; 26:1, s. 87-99
-
Tidskriftsartikel (refereegranskat)abstract
- Processing rewarding and aversive signals lies at the core of many adaptive behaviors, including value-based decision making. The brain circuits processing these signals are widespread and include the prefrontal cortex, amygdala and striatum, and their dopaminergic innervation. In this review, we integrate historic findings on the behavioral and neural mechanisms of value-based decision making with recent, groundbreaking work in this area. On the basis of this integrated view, we discuss a neuroeconomic framework of value-based decision making, use this to explain the motivation to pursue rewards and how motivation relates to the costs and benefits associated with different courses of action. As such, we consider substance addiction and overeating as states of altered value-based decision making, in which the expectation of reward chronically outweighs the costs associated with substance use and food consumption, respectively. Together, this review aims to provide a concise and accessible overview of important literature on the neural mechanisms of behavioral adaptation to reward and aversion and how these mediate motivated behaviors.
|
|
