Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Reading rats’ minds

29.11.2018

Scientists can predict where a rat will go next based on how its hippocampal neurons fire – Study published in Neuron

Place cells in the hippocampus fire when we are in a certain position – this discovery by John O’Keefe, May-Britt Moser and Edvard Moser brought them the Nobel Prize in Medicine in 2014. Based on which place cell fires, scientists can determine were a rat is.


Thoughts

IST Austria/Birgit Rieger

Neuroscientists are now able to tell where a rat will go next, just from observing which neuron fires in a task that tests rats’ reference memory.

These are the results of a study published today in Neuron, carried out by the group of Jozsef Csicsvari at the Institute of Science and Technology Austria (IST Austria), with first author and postdoc Haibing Xu, and Csicsvari’s former postdocs Peter Baracskay and Joseph O’Neill, now faculty at Cardiff University.

Scientists can infer a rat’s location based on which place cell - found in the brain region called hippocampus - sends signals. However, sometimes the place cell that is active does not correspond with the rat’s current location.

“This gives us an insight into what the animal is thinking about space”, says Jozsef Csicsvari. “We used this concept to understand how rats think during tasks that test their spatial memory.”

In the experiments, rats navigated through a maze with eight arms. Three arms contained food rewards. The rats revisited the maze so that they formed memories of where the rewards were hidden. This task teases apart two different forms of spatial memory: reference and working memory.

Reference memory is the memory that allows a rat to remember which arms contain rewards, and which arms don’t. Working memory is the memory that keeps track of which arms the rat hasn’t been to yet and which ones it has already visited, so that the rat doesn’t make unnecessary trips.

The researchers can test pure working memory by modifying the experiment so that only arms that contain rewards are open, or pure reference memory by closing off arms that have been visited already.

The researchers then asked: how do place cells fire when rats navigate a maze, and how does firing differ between reference and working memory tasks? At the center of the maze, before the rat enters the next arm, the sequence of place cells that fire corresponds either to the route the rat took in the last arm it visited, or to the arm it is going to run down next.

In tasks testing reference memory, the sequence corresponds to the next maze arm the rat will visit, giving the researchers a glimpse into the rat’s immediate plans. “The animal is thinking about a different place than the one it is in. In fact, we can predict which arm the rat will enter next”, Csicsvari explains.

Not only can the researchers predict where the rat will go next, they also know when the rat will make a mistake, says Csicsvari: “When the rat makes a mistake, it replays a random route. Based on the place cells, we can predict that the rat will make a mistake before it commits it.”

However, the prediction fails in working memory tasks. In tasks that test only working memory, the firing pattern instead replays the last arm that the animal visited.

The researchers hypothesize that the brain uses different strategies to solve reference and working memory tasks. “With reference memory, the brain truly navigates and remembers that ‘this is a location I have to go to’.

This uses the hippocampus, which is important for spatial tasks. Working memory is more abstract, each location is an item on the animal’s list of places to visit. The hippocampus probably signals to the prefrontal cortex where the rat was, and the prefrontal cortex keeps track of which items it can tick off”, Csicsvari summarizes.

About IST Austria
The Institute of Science and Technology (IST Austria) is a PhD-granting research institution located in Klosterneuburg, 18 km from the center of Vienna, Austria. Inaugurated in 2009, the Institute is dedicated to basic research in the natural and mathematical sciences. IST Austria employs professors on a tenure-track system, postdoctoral fellows, and doctoral students. While dedicated to the principle of curiosity-driven research, the Institute owns the rights to all scientific discoveries and is committed to promote their use. The first president of IST Austria is Thomas A. Henzinger, a leading computer scientist and former professor at the University of California in Berkeley, USA, and the EPFL in Lausanne, Switzerland. The graduate school of IST Austria offers fully-funded PhD positions to highly qualified candidates with a bachelor's or master's degree in biology, neuroscience, mathematics, computer science, physics, and related areas. http://www.ist.ac.at

Wissenschaftliche Ansprechpartner:

Jozsef Csicsvari
Institute of Science and Technology Austria (IST Austria)
Phone: +43 (0)2243 9000-4301
E-mail: jozsef.csicsvari@ist.ac.at

Originalpublikation:

Haibing Xu, Peter Baracskay,Joseph O’Neill, and Jozsef Csicsvari, “Assembly responses of hippocampal CA1 place cells predict learned behavior in goal-directed spatial tasks on the radial eight-arm maze", Neuron, 2018, DOI: 10.1016/j.neuron.2018.11.015

Weitere Informationen:

https://ist.ac.at/en/research/research-groups/csicsvari-group/

Dr. Elisabeth Guggenberger | idw - Informationsdienst Wissenschaft

Further reports about: Neuron memory tasks prefrontal cortex rats spatial memory working memory

More articles from Studies and Analyses:

nachricht How to design city streets more fairly
18.05.2020 | Mercator Research Institute on Global Commons and Climate Change (MCC) gGmbH

nachricht Insects: Largest study to date confirms declines on land, but finds recoveries in freshwater – Highly variable trends
24.04.2020 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Restoring vision by gene therapy

Latest scientific findings give hope for people with incurable retinal degeneration

Humans rely dominantly on their eyesight. Losing vision means not being able to read, recognize faces or find objects. Macular degeneration is one of the major...

Im Focus: Small Protein, Big Impact

In meningococci, the RNA-binding protein ProQ plays a major role. Together with RNA molecules, it regulates processes that are important for pathogenic properties of the bacteria.

Meningococci are bacteria that can cause life-threatening meningitis and sepsis. These pathogens use a small protein with a large impact: The RNA-binding...

Im Focus: K-State study reveals asymmetry in spin directions of galaxies

Research also suggests the early universe could have been spinning

An analysis of more than 200,000 spiral galaxies has revealed unexpected links between spin directions of galaxies, and the structure formed by these links...

Im Focus: New measurement exacerbates old problem

Two prominent X-ray emission lines of highly charged iron have puzzled astrophysicists for decades: their measured and calculated brightness ratios always disagree. This hinders good determinations of plasma temperatures and densities. New, careful high-precision measurements, together with top-level calculations now exclude all hitherto proposed explanations for this discrepancy, and thus deepen the problem.

Hot astrophysical plasmas fill the intergalactic space, and brightly shine in stellar coronae, active galactic nuclei, and supernova remnants. They contain...

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

New image of a cancer-related enzyme in action helps explain gene regulation

05.06.2020 | Life Sciences

Silicon 'neurons' may add a new dimension to computer processors

05.06.2020 | Physics and Astronomy

Protecting the Neuronal Architecture

05.06.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>