Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deciphering the emergence of neuronal diversity

30.01.2017

Researchers at the University of Geneva (UNIGE) have decoded the molecular diversity of inhibitory neurons during cortical development

The development of cerebral cortex plays a major role in the evolution of species and in particular for mankind. This is why scientists are studying the emergence of its cellular microstructure with high resolution methods. Neuroscientists at the University of Geneva (UNIGE), Switzerland, have analysed the diversity of cortical neurons -- more precisely inhibitory interneurons -- during the developmental period surrounding birth.


Inhibitory interneurons labelled with a fluorescent molecule (in green) are distributed in the cerebral cortex. These cells were individually isolated and single cell transcriptomics revealed markers (in white) specifically expressed in distinct sub-groups of interneurons.

Credit: © Dayerlab UNIGE.

They have discovered the emergence of three main sub-groups of interneurons by decoding the expression of cell-type specific genes as well as their exact, and often unexpected, location in the cortex. These results, which can be read in Nature Communications, will open the door to a more accurate understanding of the complex cell-type specific mechanisms underlying neuro-developmental disorders such as autism and schizophrenia. This should help researchers in discovering how psychiatric-related genetic disturbances impact the emergence of neuronal sub-types and how to design novel cell-type specific interventions.

Our cerebral cortex comprises two main types of neurons: excitatory neurons (80%), which generate cortical activity, and inhibitory interneurons (20%), which fine-tune this activity. Cortical brain function therefore depends on this neuronal diversity made up of numerous excitatory and inhibitory interneuron sub-groups.

The team of Alexandre Dayer, Professor in the Departments of Psychiatry and Fundamental Neurosciences at UNIGE's Faculty of Medicine, studied inhibitory neurons during the embryonic and early postnatal phase just after birth. In adults, over 20 interneuron sub-types have been identified. But when do they appear? When do they differentiate themselves?

"To discover this, we used transgenic mice, where specific types of inhibitory interneurons were labelled by fluorescent molecules. These fluorescent cells were studied during early development, just before the birth of the mouse and a few days after. Using a technique called fluorescence activated cell sorting, labelled neurons were isolated from the cerebral cortex and the genetic code of each of these neurons was analysed using single-cell transcriptomics," explains Alexandre Dayer. Thus, the molecular diversity of cell types is currently being dissected thanks to tools providing access to the gene expression landscape of individual cells at a given point in time during development.

Following gene sequencing of all these unique cells, bioinformatics tools allow scientists to identify distinct sub-groups of interneurons and to track the timing of their emergence during the early postnatal period. They also discovered that the location of these inhibitory interneuron sub-types varied depending on their genetic identity. "What is surprising is that one of the identified sub-groups was located in the cortical white matter, and not in the grey matter, as is usually the case," adds Professor Dayer. Indeed, the cortical white matter contains numerous fibres which transmit neuronal activity information from one cortical region to the other. The UNIGE neuroscientists, still need to discover what role this specific interneuron sub-group plays in the white matter and also how the large diversity of inhibitory interneurons appears over time.

A new database

A detailed analysis of the cell-type specific gene expression patterns belonging to these three main inhibitory interneuron sub-groups, is available to the scientific community online. This research is important when studying neuro-developmental disorders since cortical interneurons are a privileged target in psychiatric illnesses such as autism and schizophrenia. "Thanks to single-cell transcriptomics, we were able to map gene expression patterns for each cell at a given time during normal development. Hereafter, we can use this large reference database to determine how developmental disorders specifically affect individual cell types during the course of development," explains Alexandre Dayer. Cortical interneurons play a key role in the physio-pathology of psychiatric disorders. It is now necessary to determine when and how psychiatric-associated risk genes affect interneuron subtypes and to test therapies which could directly target specific cell types during developmental time windows. This is the direction that Professor Dayer's team will be taking in their future work within the framework of the National Research Centre - Synapsy.

Media Contact

Alexandre Dayer
alexandre.dayer@unige.ch
41-223-795-386

 @UNIGEnews

http://www.unige.ch 

Alexandre Dayer | EurekAlert!

More articles from Health and Medicine:

nachricht The genes are not to blame
20.07.2018 | Technische Universität München

nachricht Targeting headaches and tumors with nano-submarines
20.07.2018 | Universitätsmedizin der Johannes Gutenberg-Universität Mainz

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>