Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


To proliferate or not to proliferate


Shape of neural progenitor cells influences brain size

The brains of different mammals vary significantly in size. During human evolution, the size of the brain and the number of neurons therein increased profoundly, especially in a particular region called the neocortex, which is the seat of our higher cognitive abilities.

The picture shows a human basal progenitor with its extensions. The cell was detected upon application of a lipophilic dye, DiI (magenta), on the basal side of the human fetal neocortical tissue. Scale bar, 10 µm.

Copyright: Kalebic et al. Cell Stem Cell / MPI-CBG

Neurons are generated by neural progenitor cells, and more neural progenitors means more neurons and a bigger brain. Past studies had implicated one specific class of neural progenitors, called basal progenitors, as a key driver of neocortex expansion.

However, it remained largely unknown what underlies the ability of basal progenitors to proliferate, that is to produce more basal progenitors. Researchers at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) in Dresden now identified an underlying mechanism.

They found that the shape of those cells determines how much they proliferate. This suggests that cell shape is a key cell biological feature contributing to the evolutionary expansion of the neocortex. The researchers published their findings in the journal Cell Stem Cell.

Why did the human neocortex expand so profoundly during evolution? A bigger neocortex is associated with an increased number of neurons and can provide better cognitive abilities. Neurons are produced during fetal development by progenitor cells. Neocortical progenitor cells in human are more proliferative than in other mammals, which means that they divide more times, generating additional progenitors before they produce neurons.

As a consequence, the final number of neocortical neurons is increased. Among the different classes of neocortical progenitors, the so-called basal progenitors are thought to be the driving force for a bigger brain. It was already known that basal progenitors come in different shapes, with or without cell extensions, but it was unknown what the function of these extensions was and whether their number differed across mammalian species.

Researchers in the group of Wieland Huttner at the MPI-CBG sought to address this question. With the support of colleagues from the University Hospital Carl Gustav Carus in Dresden and the Max Planck Institute for Experimental Medicine in Göttingen, they compared and quantified the shape of basal progenitors in the developing neocortex of mice, ferrets, and humans. They found that human basal progenitors have more cell extensions than those of mice and ferrets. That was new to the science world.

Might that have something to do with the enhanced proliferative capacity of human basal progenitors? Nereo Kalebic, the first author of the study, explains: “First, we wanted to know why human basal progenitors have more extensions, and discovered that the protein PALMDELPHIN, which is associated with the inner side of the cell membrane, enables the growth of additional extensions.

There it was – the unknown mechanism that influences the shape of basal progenitor cells!” Nereo continues: “Secondly, we also found out that when a basal progenitor has more extensions, its ability to proliferate is increased, which ultimately results in the production of more neurons.” The researchers showed this by introducing human PALMDELPHIN into the embryonic neocortex of mice and ferrets, which caused the growth of more extensions on basal progenitors and an increase in their proliferation.

In contrast, when the expression of PALMDELPHIN was disrupted in fetal human neocortical tissue, the number of basal progenitor extensions and basal progenitor proliferation were reduced. The researchers' findings culminated in the novel concept that a greater number of cell extensions enabled basal progenitors to more effectively receive pro-proliferative signals from their environment.

This study shows for the first time that the shape of a progenitor cell causes a change in proliferation. Wieland Huttner, the supervisor of the study, summarizes: “Our findings offer a missing link between the shape of basal progenitors and their ability to proliferate and thus create a bigger pool of progenitor cells, which is required for the production of a greater number of neurons. This suggests that changes in basal progenitor cell shape may have contributed to the evolutionary expansion of the human neocortex.”

Wissenschaftliche Ansprechpartner:

Wieland Huttner
+49 (0) 351 210 1500

Nereo Kalebic
+49 (0) 351 210 2516


Nereo Kalebic, Carlotta Gilardi, Barbara Stepien, Michaela Wilsch-Bräuninger, Katherine
R. Long, Takashi Namba, Marta Florio, Barbara Langen, Benoit Lombardot, Anna
Shevchenko, Manfred W. Kilimann, Hiroshi Kawasaki, Pauline Wimberger, Wieland B.
Huttner: “Neocortical expansion due to increased proliferation of basal progenitors is linked to changes in their morphology” Cell Stem Cell, 21. March, 2019.

Katrin Boes | Max-Planck-Institut für molekulare Zellbiologie und Genetik
Further information:

More articles from Life Sciences:

nachricht If Machines Could Smell ...
19.07.2019 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Algae-killing viruses spur nutrient recycling in oceans
18.07.2019 | Rutgers University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Better thermal conductivity by adjusting the arrangement of atoms

Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.

In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...

Im Focus: First-ever visualizations of electrical gating effects on electronic structure

Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.

Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...

Im Focus: Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow

Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...

Im Focus: Artificial neural network resolves puzzles from condensed matter physics: Which is the perfect quantum theory?

For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.

Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...

Im Focus: Extremely hard yet metallically conductive: Bayreuth researchers develop novel material with high-tech prospects

An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".

The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

Latest News

Heat flow through single molecules detected

19.07.2019 | Physics and Astronomy

Heat transport through single molecules

19.07.2019 | Physics and Astronomy

Welcome Committee for Comets

19.07.2019 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>