Nav: Home

Connecting neurons in the brain

May 02, 2019

The brain consists of a large collection of interconnected neurons. How complex patterns of neuronal cells grow into functioning circuits during development has fascinated researchers for decades. A team of scientists at VIB and KU Leuven has now uncovered a new signaling mechanism in fruit flies that specifies the formation of neuronal circuits in the brain.

About 100 billion neurons form a complex and interconnected network in our brain, allowing us to generate complex thought patterns and actions. Neurons come in all sizes and shapes, but they mostly have long protrusions that connect to neighboring cells through specialized information-transmission structures called synapses.

How this intricate network takes shape during early development captivates many neuroscientists, including Prof. Dietmar Schmucker (VIB-KU Leuven) who has built a career studying neuronal wiring. "Proper brain functioning relies on very controlled branching of neuronal cell-extensions called axons and dendrites, and the correct formation of synapses at precise locations along these branches," he says. "Specifying synapse formation determines where and how many potential connections a neuronal cell is "allowed" to form. Therefore, controlling synapse numbers at each neuronal branch is essential for the correct formation of complex brain circuits."

A new player


Schmucker's team turned to the developing fly brain to study which molecular players control synapse formation in specific subcellular compartments. Using a genetic single-cell approach, the researchers could label and manipulate individual neuronal protrusions in the nervous system of the fruit fly, a popular model organism for neuroscientists.

"We found differences in neuronal branching and in synapse numbers at individual protrusions of neurons of the same type," explains Olivier Urwyler a postdoc in the lab, who developed this new experimental system. Urwyler, now a group leader at University Zurich, found that a phosphatase called Prl-1 was decisive for specifying where to form the highest density of synaptic connections on a given neuron.

In fruit flies, loss of Prl-1 led to defects in the formation of neuronal connections in several different circuits, suggesting that this protein phosphatase is of general importance in circuit formation. The team also identified through which signaling pathway Prl-1 exerts its function.

"Surprisingly, it turns out to be one of the most ubiquitously acting signaling pathways, the Insulin receptor/Akt/mTor pathway, required in many physiological responses, cellular growth and cancer, says Urwyler. "Restricting the subcellular protein distribution of Prl-1 to a small compartment results in this potent signaling cascade to locally boost synapse formation."

From flies to humans?


Flies that lack Prl-1 show severe locomotor problems. Interestingly, if Prl-1 is erroneously overexpressed and out of control, it can drive metastatic behavior of cancer cells.

As Prl-1 phosphatases are conserved from invertebrates to mammals, what could this imply for humans? According to Schmucker, their presence in different regions of the human brain means that Prl-1 phosphatases are poised to function in a similar way during vertebrate brain development:

"The compartmentalized restriction of Prl-1 could serve as a specificity factor to control the precise tuning of synaptic connections in human neurons as well, similar to the effects we have shown for the assembly of neuronal circuits and synapses in fruit flies."
-end-
Publication

Prl-1 phosphatase directs compartmentalized control of InR/Akt signaling during CNS synapse formation, Urwyler et al., Science 2019

Questions from patients

A breakthrough in research is not the same as a breakthrough in medicine. The realizations of VIB researchers can form the basis of new therapies, but the development path still takes years. This can raise a lot of questions. That is why we ask you to please refer questions in your report or article to the email address that VIB makes available for this purpose: patienteninfo@vib.be. Everyone can submit questions concerning this and other medically-oriented research directly to VIB via this address.

VIB (the Flanders Institute for Biotechnology)

Related Neurons Articles:

A molecule that directs neurons
A research team coordinated by the University of Trento studied a mass of brain cells, the habenula, linked to disorders like autism, schizophrenia and depression.
Shaping the social networks of neurons
Identification of a protein complex that attracts or repels nerve cells during development.
With these neurons, extinguishing fear is its own reward
The same neurons responsible for encoding reward also form new memories to suppress fearful ones, according to new research by scientists at The Picower Institute for Learning and Memory at MIT.
How do we get so many different types of neurons in our brain?
SMU (Southern Methodist University) researchers have discovered another layer of complexity in gene expression, which could help explain how we're able to have so many billions of neurons in our brain.
These neurons affect how much you do, or don't, want to eat
University of Arizona researchers have identified a network of neurons that coordinate with other brain regions to influence eating behaviors.
Mood neurons mature during adolescence
Researchers have discovered a mysterious group of neurons in the amygdala -- a key center for emotional processing in the brain -- that stay in an immature, prenatal developmental state throughout childhood.
Connecting neurons in the brain
Leuven researchers uncover new mechanisms of brain development that determine when, where and how strongly distinct brain cells interconnect.
The salt-craving neurons
Pass the potato chips, please! New research discovers neural circuits that regulate craving and satiation for salty tastes.
When neurons are out of shape, antidepressants may not work
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed medication for major depressive disorder (MDD), yet scientists still do not understand why the treatment does not work in nearly thirty percent of patients with MDD.
Losing neurons can sometimes not be that bad
Current thinking about Alzheimer's disease is that neuronal cell death in the brain is to blame for the cognitive havoc caused by the disease.
More Neurons News and Neurons Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Teaching For Better Humans 2.0
More than test scores or good grades–what do kids need for the future? This hour, TED speakers explore how to help children grow into better humans, both during and after this time of crisis. Guests include educators Richard Culatta and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 3: Shared Immunity
More than a million people have caught Covid-19, and tens of thousands have died. But thousands more have survived and recovered. A week or so ago (aka, what feels like ten years in corona time) producer Molly Webster learned that many of those survivors possess a kind of superpower: antibodies trained to fight the virus. Not only that, they might be able to pass this power on to the people who are sick with corona, and still in the fight. Today we have the story of an experimental treatment that's popping up all over the country: convalescent plasma transfusion, a century-old procedure that some say may become one of our best weapons against this devastating, new disease.   If you have recovered from Covid-19 and want to donate plasma, national and local donation registries are gearing up to collect blood.  To sign up with the American Red Cross, a national organization that works in local communities, head here.  To find out more about the The National COVID-19 Convalescent Plasma Project, which we spoke about in our episode, including information on clinical trials or plasma donation projects in your community, go here.  And if you are in the greater New York City area, and want to donate convalescent plasma, head over to the New York Blood Center to sign up. Or, register with specific NYC hospitals here.   If you are sick with Covid-19, and are interested in participating in a clinical trial, or are looking for a plasma donor match, check in with your local hospital, university, or blood center for more; you can also find more information on trials at The National COVID-19 Convalescent Plasma Project. And lastly, Tatiana Prowell's tweet that tipped us off is here. This episode was reported by Molly Webster and produced by Pat Walters. Special thanks to Drs. Evan Bloch and Tim Byun, as well as the Albert Einstein College of Medicine.  Support Radiolab today at Radiolab.org/donate.