Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Neuronal circuits in the brain 'sense' our inner state

15.07.2020

How decisions are made and how behavior is controlled is one of the most important questions in neuroscience. The neurotransmitter dopamine plays a central role in all of this. Scientists at the Technical University of Munich (TUM), together with researchers at the Max Planck Institute of Neurobiology, looked into the role that dopamine plays in the decision-making process and in controlling movement.

Animals have an innate preference for certain scents and tastes. Attractive scents are linked to things like good food. Less attractive scents – that of spoiled food, for example – instinctively give the animal a signal which says: “There could be danger here!”


Dopamine helps animals like the fly Drosophila melanogaster to classify good and bad (symbolized by black and white) in their decisions.

Nicolas Gompel

Free for use in reporting on TUM, with the copyright noted.


Prof. Dr. Ilona Grunwald Kadow

A. Eckert / TUM

Free for use in reporting on TUM, with the copyright noted.

When it comes to taste, all animals have similar preferences: Sugars and fats are perceived positively, whereas a bitter taste is perceived rather negatively.

In order to be able to make such evaluations, we need signals in the brain that tell us “This is good” or “This is bad”. The dopaminergic system in the brain, better known as the reward system, plays an important role in these evaluations.

Understanding what happens in the brain

Neurons that produce dopamine, known as dopaminergic neurons, play a role in a range of diseases, from addictive behavior and obesity to Parkinson's disease. In addiction or obesity, the reward system signals can be too strong or also too weak. In Parkinson’s disease, dopaminergic neurons degenerate, and this affects the control of motor functions.

To learn more about the processes in the brain, basic research is essential. Ilona Grunwald Kadow, Professor of Neural Control of Metabolism at the TUM School of Life Sciences in Weihenstephan, and her team are conducting research on the fly Drosophila melanogaster.

Neuroscientists often use this fly as a model because its neuronal networks are much simpler than those of humans. Using genetic tricks, scientists can turn individual network components on and off or change them.

This enables the researchers to understand the principles of neuronal circuits that underlie the functions of more complex brains. "Dopamine plays a very similar role in the brain of humans and insects," explains the scientist.

Further clarifying the effect of dopamine

Dopamine is one of the most intensively studied signals in the brain. It is involved in both cognitive (e.g. motivation, reinforcement, goal-oriented behavior, motor control and movement, decision-making and learning) and more basic functions (e.g. reproduction and nausea).

How dopamine contributes to the various aspects of neural circuit functionality and behavior is an open question, but it is believed that dopaminergic neurons use different activity patterns to send a signal to the brain about what the body needs and senses.

“We have now investigated the activity of the dopaminergic neurons in greater detail,” said Ilona Grunwald Kadow. The team developed a custom 3D-imaging method based on in-vivo calcium imaging, as calcium is a good indicator of neuronal activity.

Neurons react flexibly and individually

Using this method, the research team was able to show that the activity of a network of dopaminergic neurons reflects both the innate preferences for smell and taste as well as the physiological state of the organism.

In addition to sensory stimuli such as smell or taste, dopaminergic neurons also record information as to whether an organism is moving or not. The neurons can respond to both internal behavioral states and external signals, bring them together, and use this to support both cognitive and motor processes.

"By doing that, the neurons can react flexibly and individually to the most important information – such as smell, taste, but also hunger or one’s own movement. This is important to reach a balanced decision, because an external sensory signal can sometimes mean something good or bad, depending on an organism’s condition," says Prof. Grunwald Kadow.

Surprising results

The researchers were surprised that dopaminergic neurones behave quite differently in different animals. The scientists speculate that this might explain individual preferences and behavioral differences between individuals.

In addition, the researchers found that the movement of the animal not only activates these dopaminergic neurones, but also other areas of the brain that actually have nothing per se to do with movement. This provides starting points for further research, for example what role movement plays in general when reacting to an environmental stimulus.

Wissenschaftliche Ansprechpartner:

Prof. Dr. Ilona Grunwald Kadow
Technical University of Munich
Professorship of Neuronal Control of Metabolism
TUM School of Life Sciences
Tel.: +49 8161 71-2491
ilona.grunwald(at)tum.de

Originalpublikation:

Siju et al.: "Valence and state-dependent population coding in dopaminergic neurons in the fly mushroom body". Current Biology (https://www.sciencedirect.com/science/article/pii/S0960982220305510?via%3Dihub)

Weitere Informationen:

https://www.tum.de/nc/en/about-tum/news/press-releases/details/36143/ (Press release)
https://www.neuro.mpg.de/news/2020-07-portugues/en (Press release @MPI)
https://mediatum.ub.tum.de/1553341 (High resolution images)
https://www.wzw.tum.de/index.php?id=2&L=1 (TUM School of Life Sciences)
https://www.professoren.tum.de/en/grunwald-kadow-ilona (Prof. Ilona Grunwald Kadow)
https://www.neuro.wzw.tum.de/ (Professorship of Neuronal Control of Metabolism)

Pressestelle Corporate Communications Center | Technische Universität München

More articles from Life Sciences:

nachricht Study clarifies kinship of important plant group
05.08.2020 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht Human cell-based test systems for toxicity studies: Ready-to-use Toxicity Assay (hiPSC)
05.08.2020 | Fraunhofer-Institut für Biomedizinische Technik IBMT

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New Strategy Against Osteoporosis

An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.

Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...

Im Focus: AI & single-cell genomics

New software predicts cell fate

Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...

Im Focus: TU Graz Researchers synthesize nanoparticles tailored for special applications

“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.

Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...

Im Focus: Tailored light inspired by nature

An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.

Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...

Im Focus: NYUAD astrophysicist investigates the possibility of life below the surface of Mars

  • A rover expected to explore below the surface of Mars in 2022 has the potential to provide more insights
  • The findings published in Scientific Reports, Springer Nature suggests the presence of traces of water on Mars, raising the question of the possibility of a life-supporting environment

Although no life has been detected on the Martian surface, a new study from astrophysicist and research scientist at the Center for Space Science at NYU Abu...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“Conference on Laser Polishing – LaP 2020”: The final touches for surfaces

23.07.2020 | Event News

Conference radar for cybersecurity

21.07.2020 | Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

 
Latest News

Manifestation of quantum distance in flat band materials

05.08.2020 | Physics and Astronomy

Discovery shows promise for treating Huntington's Disease

05.08.2020 | Health and Medicine

Rock debris protects glaciers from climate change more than previously known

05.08.2020 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>