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Summary: For the first time, researchers have directly observed dopamine release in the human brain during moments of cognitive flexibility. Using PET images, they found that dopamine levels increase in the ventromedial prefrontal cortex when people change between tasks, and the more dopamine is released, the more efficiently it was adapted.
This confirms a biochemical link between dopamine and the ability of the brain to adjust behavior in response to changing demands. The discovery can help refine treatments for disorders such as Parkinson, depression, ADHD and schizophrenia, which often affect flexible thinking.
Key facts:
Dopamine and adaptability: the highest dopamine release is correlated with a better task switching. Identified brain region: PET scans showed dopamine activity in the ventromedial prefrontal cortex. Clinical relevance: The results can guide treatments for psychiatric and neurological disorders with alternative cognitive flexibility.
Source: SNMMI
For the first time, scientists have confirmed a neurobyochemical bond between dopamine and cognitive flexibility, according to new research published in the March edition of the Journal of Nuclear Medicine.
PET images show that the brain increases dopamine production by completing cognitively demanding tasks, and that the more dopamine is released, the more efficiently the tasks are completed.
Armed with this information, doctors can soon develop more precise treatment strategies for neurological and psychiatric disorders.
Cognitive flexibility is the ability to adapt the thought and behavior from one to a changing environment and is considered an aspect of the executive function. Cognitive flexibility differs among people and is reported that it is affected in several psychiatric and neurological disorders, such as depression, post -traumatic stress disorder, addiction, anxiety disorder, schizophrenia, Parkinson’s disease and deficit/hyperactivity disorder of attention.
“At the level of neurotransmitters, the dopamine system has been linked to cognitive flexibility. However, a direct neurochemistry response to cognitive flexibility has not yet been shown,” said Isabelle Ciederer, PHD, associated teacher in experimental nuclear medicine in the department of nuclear medicine at the Mainz University Medical Center, Germany.
“In our study, we seek to examine the release of dopamine in real time making PET scanns, while people completed behavioral flexibility tasks.”
Eighteen participants were scanned with the ligand of the D2/3 18f-fallypride receiver in a two-part block study design. In the first part, the participants performed two consecutively tasks on the screen of a computer without changing the rule while undergoing PET images.
In the second part of the PET exploration, the participants had to change flexibly between two rules of tasks. Dopamine release was calculated using the lineized simplified reference region model that compares the two blocks of tasks with each other.
The PET image analysis showed a displacement of 18F-Fallypride in the ventromedial prefrontal cortex during the task switching part (greater cognitive demand) of the study, which is supposed to be the release of dopamine. The results also showed that the greatest release of dopamine, the most efficient participants were changing between tasks.
“Current findings emphasize the importance of dopamine in cognitive flexibility,” said Mathias Schreckenberger, MD, head of the Nuclear Medicine Department of the Mainz University Medical Center.
“They are consistent with the results of previous clinical studies that indicate that dopamine deficiency in disorders such as Parkinson’s disease can cause behavior deficit in cognitive flexibility.”
“Looking to the future, the results of the study are expected to contribute to a better understanding of the neurochemical mechanisms underlying cognitive flexibility and, therefore, facilitate the development of treatment strategies to improve flexibility in neurological and psychiatric disorders,” he continued.
On this Dopamine and Neuroscience Research News
Author: Rebecca Maxey
Source: SNMMI
Contact: Rebecca Maxey – Snmmi
Image: The image is accredited to Neuroscience News
Original research: open access.
“Dopaminergic mechanisms of cognitive flexibility: a study (18f) Fallypride Pet” by Isabelle Miederer et al. Nuclear Medicine Magazine
Abstract
Dopaminergic mechanisms of cognitive flexibility: a study (18f) Fallypride Pet
Cognitive flexibility is the ability to adequately adapt thinking and behavior to changing environmental demands and is conceptualized as an aspect of the executive function. The dopamine system has been involved in cognitive flexibility; However, a direct link, that is, neurochemical, with cognitive flexibility has not yet been demonstrated.
The objective of this study was, therefore, investigating how cognitive flexibility is mediated by dopaminergic signage in the ventromedial prefrontal cortex (VMPFC).
METHODS: Eighteen participants were measured in a PET study with 174 ± 12 MBQ of the ligand of the receiver D2/3 (18F) Fallypride in a block design with 2 parts. While the participants processed 2 tasks sequentially without changing on the screen of a computer in the first part of the PET exploration, they had to change flexibly between the 2 rules of tasks after 100 minutes after the injection in the second part.
The release of dopamine (γ) was quantified using the model of linear simplified reference region that contrasts the 2 blocks of tasks (switching versus change/baseline).
Results: The statistical analysis of the parametric γ images showed that the increase in cognitive demand during the switching of tasks induced a displacement of the receptor ligand d2/3 (18f) Fallypride in the VMPFC (maximum value t = 13.8; cluster size: 528 Voxels; Family error rate-correction of the error rate <0.001 0.022 ± 0.006 min-1.
Conclusion: As far as we know, this is the first experimental PET study that shows the direct participation of dopamine in the VMPFC in a paradigm of change of tasks, which confirms the assumptions of the model on the neurochemical basis of cognitive flexibility.
