Threatened sturgeon learns for the fitness

May 07, 2019

An international team led by IGB is providing one of the first proofs of the complex learning behaviour of fish in a recent study. The Atlantic sturgeon is considered extinct in Germany. The IGB is coordinating the reintroduction of these up to five meter large river giants and is investigating whether sturgeon training can increase their fitness for the wild. An important fitness factor is their feeding behavior. Already a two-week "learning lead" made the search for food more efficient. In addition, the increased formation of the transcription factor neurod1 - an important neuronal component of learning - could be demonstrated in the brain of the trained sturgeons.

Sturgeons are among the most endangered fish species in the world. In the past, two species of these migratory fish were native to the North Sea and Baltic tributaries of Germany. The European sturgeon (Acipenser sturio) lived in the North Sea and the catchment areas of the Elbe, the Atlantic sturgeon (Acipenser oxyrinchus) settled in the Baltic Sea and the catchment areas of the Oder. The IGB develops the scientific basis for the reintroduction of these two species in Germany. This also includes stocking measures with pre-reared young fish. "We have the highest mortality rate of reintroduced sturgeons in the first days in the wild. The faster the animals adapt to the new conditions, the higher the chance of survival.With our investigations we want to create the basis to optimally prepare the animals for the reintroduction," is how the IGB researcher and study leader, Sven Wuertz, describes the background of the study.

Little known about the learning behaviour of fish so far

Compared to mammals, the formation of nerve cells in the brain in fish is very dynamic and remains active throughout life. This enables fish to react very well to changes in their environment. So far, however, there are only few scientific findings on the underlying physiological processes of the learning behaviour in fish.

Like a vacuum cleaner, sturgeons pick up their prey from the bottom of the watercourse

In the behavioural studies, sturgeons were divided into two groups and kept in large current channels; in nature, sturgeons feed on small organisms such as insect larvae and crustaceans, which they suck up from the fine sandy bottom of the water. The "training team" had to look for food from a handful of sand in their rearing tank for two weeks in order to imitate food intake under natural conditions The group without training was given the insect larvae on the bare floor of the current channel. After two weeks, both groups had to search for their prey in a current channel with completely covered sandy soil in which the food was buried.

The training shows effect

The trained fish found the food twice as fast as their untrained conspecifics and there were also differences in the brain structure. Neurod1 is a transcription factor that is produced in greater numbers when new nerve cells are formed. It serves as an indicator for the neuronal component of learning. The gene expression of neurod1 was significantly higher in the trained animals than in the untrained ones. The complicated search for food thus caused the animals' brains to be more active and to process learning experiences. "The results are significant from a scientific point of view, as there is little evidence to date for the complex learning behaviour of fish. From the point of view of species protection, the results are also very important: Based on the results, we can further optimize the rearing conditions for our sturgeons," summarizes Joern Gessner, co-author of the study and coordinator of the reintroduction program.

Forschungsverbund Berlin

Related Nerve Cells Articles from Brightsurf:

Nerve cells let others "listen in"
How many ''listeners'' a nerve cell has in the brain is strictly regulated.

Nerve cells with energy saving program
Thanks to a metabolic adjustment, the cells can remain functional despite damage to the mitochondria.

Why developing nerve cells can take a wrong turn
Loss of ubiquitin-conjugating enzyme leads to impediment in growth of nerve cells / Link found between cellular machineries of protein degradation and regulation of the epigenetic landscape in human embryonic stem cells

Unique fingerprint: What makes nerve cells unmistakable?
Protein variations that result from the process of alternative splicing control the identity and function of nerve cells in the brain.

Ragweed compounds could protect nerve cells from Alzheimer's
As spring arrives in the northern hemisphere, many people are cursing ragweed, a primary culprit in seasonal allergies.

Fooling nerve cells into acting normal
In a new study, scientists at the University of Missouri have discovered that a neuron's own electrical signal, or voltage, can indicate whether the neuron is functioning normally.

How nerve cells control misfolded proteins
Researchers have identified a protein complex that marks misfolded proteins, stops them from interacting with other proteins in the cell and directs them towards disposal.

The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.

Research confirms nerve cells made from skin cells are a valid lab model for studying disease
Researchers from the Salk Institute, along with collaborators at Stanford University and Baylor College of Medicine, have shown that cells from mice that have been induced to grow into nerve cells using a previously published method have molecular signatures matching neurons that developed naturally in the brain.

Bees can count with just four nerve cells in their brains
Bees can solve seemingly clever counting tasks with very small numbers of nerve cells in their brains, according to researchers at Queen Mary University of London.

Read More: Nerve Cells News and Nerve Cells Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to