Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How decisions unfold in a zebrafish brain

17.01.2020

Researchers at the Rockefeller University and the Research Institute of Molecular Pathology (IMP) in Vienna, alongside collaborators, were able to track the activity of individual neurons in the entire brain of zebrafish larvae, thus opening an opportunity to observe decision-making processes in unprecedented temporal and spatial resolution.

Some things we do appear almost automatic, such as opening the fridge when feeling hungry. Although such decisions do not seem to take much thought, they are in fact generated by millions of neurons and numerous interactions among several brain regions - a complex, dynamic system.


Zebrafish (Danio rerio)

IMP

Zebrafish have now opened an opportunity to observe decision-making processes in unprecedented temporal and spatial resolution.

Researchers from the labs of Alipasha Vaziri at The Rockefeller University and the Research Institute of Molecular Pathology (IMP), alongside collaborators, tracked the activity of individual neurons in the entire brain of zebrafish larvae to reconstruct the unfolding of neuronal events as the animals repeatedly made “left or right” choices.

The resulting frame-by-frame view of a decision in the making was so detailed that, ten seconds before the fish responded, the researchers could predict what their next move would be and when they would execute it. They reported their findings in the current issue of the journal Cell.

Following a decision

Understanding how a brain makes decisions involves tracking how neurons across multiple brain regions respond and cooperate. Scientists have long been stuck between two options: They can either closely observe the firing of only a subset of neurons, which limits their view of the whole picture, or look at the whole brain activity while averaging the data over multiple trials to reduce noise. Averaging, however, leads to loss of some of the details.

“We wanted to understand how decisions unfold on a trial-by-trial basis,” says Alipasha Vaziri, head of the Laboratory of Neurotechnology and Biophysics at The Rockefeller University and IMP Adjunct Investigator. To do so, the team paired advanced statistical methods with their recently developed imaging technique, light field microscopy, which enables simultaneous tracking of the activity of every neuron in the brains of zebrafish larvae.

But before subjecting the fish to experiments, the scientists had to teach them a new behaviour, one that was not merely reflexive, but goal-oriented. The goal, from the fish's perspective, was to get relief from heat.

The researchers slightly warmed the water around the fish using a laser, switching off the laser only when the fish made a tail movement to the right. After about 15 repeats, the fish had mastered the trick: They responded to their warming surroundings about 20 seconds after the laser came on. About 80 percent of the time, the fish remembered to flip their tail in the correct direction.

During the interval after the laser was turned on and before the fish made a movement, the researchers tracked the activity state of about 5,000 of the most active neurons across the entire brain. They then identified which activity patterns reflected the brain sensing the heat or moving the tail, and which appeared decision related.

Particularly, they found that about ten seconds before the fish made a movement, its brain patterns differed based on whether the fish was going to make a correct or an incorrect turn.

Having this information, the researchers could look at the brain state of any one little fish, and 80 percent of the time guess correctly what the fish was about to do: They were able to predict the specific time at which the animals would initiate the turn, and its direction, in each trial.

An unexpected player

Having found which clusters of neurons corresponded to different aspects of the task, the researchers then mapped the neurons onto their anatomical regions. “This allowed us to see what brain regions were involved in what aspects of the task as the decision unfolded in each trial,” Vaziri says.

Several brain regions participated in transforming sensory information into decision and action, but one region stood out: the cerebellum. The rate of activity of neurons in this brain part determined the exact timing of the tail movement.

“This was surprising,” Vaziri says, adding that a few studies in recent years have pointed in the same direction. “I think we might find more generally that the cerebellum is involved in more cognitive brain functions than what we have traditionally thought.”

Wissenschaftliche Ansprechpartner:

Alipasha Vaziri
The Rockefeller University
Research Institute of Molecular Pathology
vaziri@rockefeller.edu

Originalpublikation:

Qian Lin, Jason Manley, Magdalena Helmreich, Friederike Schlumm, Jennifer M. Li, Drew N. Robson, Florian Engert, Alexander Schier, Tobias Nöbauer, and Alipasha Vaziri: “Cerebellar neurodynamics predict decision timing and outcome on single-trial level." Cell, 16 January 2020.

Dr. Heidemarie Hurtl IMP Communications | idw - Informationsdienst Wissenschaft
Further information:
http://www.imp.ac.at

Further reports about: IMP Molekulare Pathologie Zebrafish brain regions neurons zebrafish larvae

More articles from Life Sciences:

nachricht "Make two out of one" - Division of Artificial Cells
19.02.2020 | Max-Planck-Institut für Kolloid- und Grenzflächenforschung

nachricht Sweet beaks: What Galapagos finches and marine bacteria have in common
19.02.2020 | Max-Planck-Institut für Marine Mikrobiologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A step towards controlling spin-dependent petahertz electronics by material defects

The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.

Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...

Im Focus: Freiburg researcher investigate the origins of surface texture

Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.

Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...

Im Focus: Skyrmions like it hot: Spin structures are controllable even at high temperatures

Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices

The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...

Im Focus: Making the internet more energy efficient through systemic optimization

Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.

Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.

Im Focus: New synthesis methods enhance 3D chemical space for drug discovery

After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.

"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

70th Lindau Nobel Laureate Meeting: Around 70 Laureates set to meet with young scientists from approx. 100 countries

12.02.2020 | Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

 
Latest News

"Make two out of one" - Division of Artificial Cells

19.02.2020 | Life Sciences

High-Performance Computing Center of the University of Stuttgart Receives new Supercomuter "Hawk"

19.02.2020 | Information Technology

A step towards controlling spin-dependent petahertz electronics by material defects

19.02.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>