Nav: Home

Major discovery in the genetics of Down syndrome

February 21, 2020

Researchers at CHU Sainte-Justine and Université de Montréal have discovered a new mechanism involved in the expression of Down syndrome, one of the main causes of intellectual disability and congenital heart defects in children. The study's findings were published today in Current Biology.

Down syndrome (SD), also called trisomy 21 syndrome, is a genetic condition that affects approximately one in every 800 children born in Canada. In these individuals, many genes are expressed abnormally at the same time, making it difficult to determine which genes contribute to which differences.

Professor Jannic Boehm's research team focused on RCAN1, a gene that is overexpressed in the brains of fetuses with Down syndrome. The team's work provides insights into how the gene influences the way the condition manifests itself.

Synaptic plasticity, memory and learning

The human brain is made up of hundreds of billions of cells known as neurons. They communicate with each other through synapses, which are small gaps between neurons. The ability of synapses to strengthen or weaken over time is known as "synaptic plasticity." It's an important biological phenomenon because it's essential for memory and learning.

"There are two kinds of synaptic plasticity: long-term potentiation, which strengthens synapses and improves interaction between neurons, and long-term depression, which weakens synapses," said Boehm, a professor at Université de Montréal and researcher at CHU Sainte-Justine.

"We already knew that synaptic plasticity is influenced by certain proteins," added Anthony Dudilot, one of the study's first authors. "For example, calcineurin is inhibited when long-term potentiation is induced, but it's activated when long-term depression begins. But the molecular mechanism underlying calcineurin regulation was less clear."

The research team found that the various signalling pathways that trigger synaptic potentiation or depression converge on RCAN1. They also determined that the gene regulates calcineurin activity by inhibiting or facilitating it.

Given its dual role as an inhibitor/facilitator, the researchers deduced that RCAN1 works as a "switch" that regulates synaptic plasticity, thereby affecting learning and memory.

A better future for all patients

"This is the first time that the molecular mechanism for calcineurin regulation in bidirectional synaptic plasticity has been determined," said Boehm. "This breakthrough explains how overexpression of the RCAN1 gene could cause intellectual disabilities in individuals with Down syndrome. It also opens up the possibility of developing innovative treatments for affected patients."
-end-
About the study

"RCAN1 regulates bidirectional synaptic plasticity" was published in Current Biology in February 2020. The first authors are Anthony Dudilot and Emilie Trillaud-Doppia, PhD candidates supervised by Jannic Boehm. The senior author is Jannic Boehm, PhD, an associate professor at UdeM's Department of Neurosciences and researcher at CHU Sainte-Justine. The study was backed by the Canadian Institutes of Health Research (CIHR), Fonds de recherche du Québec - Santé (FRQS), the Alzheimer Society of Canada and Université de Montréal.

About the CHU Sainte-Justine Research Centre

CHU Sainte-Justine Research Centre is a leading mother-child research institution affiliated with Université de Montréal. It brings together more than 200 research investigators, including over 90 clinicians, as well as 350 graduate and post-graduate students focused on finding innovative means of prevention, faster and less invasive treatments, and personalized approaches to medicine. The Centre is part of CHU Sainte-Justine, which is the largest mother-child hospital in Canada and second most important pediatric hospital in North America.

University of Montreal

Related Neurons Articles:

The first 3D map of the heart's neurons
An interdisciplinary research team establishes a new technological pipeline to build a 3D map of the neurons in the heart, revealing foundational insight into their role in heart attacks and other cardiac conditions.
Mapping the neurons of the rat heart in 3D
A team of researchers has developed a virtual 3D heart, digitally showcasing the heart's unique network of neurons for the first time.
How to put neurons into cages
Football-shaped microscale cages have been created using special laser technologies.
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.
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

Our Relationship With Water
We need water to live. But with rising seas and so many lacking clean water – water is in crisis and so are we. This hour, TED speakers explore ideas around restoring our relationship with water. Guests on the show include legal scholar Kelsey Leonard, artist LaToya Ruby Frazier, and community organizer Colette Pichon Battle.
Now Playing: Science for the People

#569 Facing Fear
What do you fear? I mean really fear? Well, ok, maybe right now that's tough. We're living in a new age and definition of fear. But what do we do about it? Eva Holland has faced her fears, including trauma and phobia. She lived to tell the tale and write a book: "Nerve: Adventures in the Science of Fear".
Now Playing: Radiolab

Uncounted
First things first: our very own Latif Nasser has an exciting new show on Netflix. He talks to Jad about the hidden forces of the world that connect us all. Then, with an eye on the upcoming election, we take a look back: at two pieces from More Perfect Season 3 about Constitutional amendments that determine who gets to vote. Former Radiolab producer Julia Longoria takes us to Washington, D.C. The capital is at the heart of our democracy, but it's not a state, and it wasn't until the 23rd Amendment that its people got the right to vote for president. But that still left DC without full representation in Congress; D.C. sends a "non-voting delegate" to the House. Julia profiles that delegate, Congresswoman Eleanor Holmes Norton, and her unique approach to fighting for power in a virtually powerless role. Second, Radiolab producer Sarah Qari looks at a current fight to lower the US voting age to 16 that harkens back to the fight for the 26th Amendment in the 1960s. Eighteen-year-olds at the time argued that if they were old enough to be drafted to fight in the War, they were old enough to have a voice in our democracy. But what about today, when even younger Americans are finding themselves at the center of national political debates? Does it mean we should lower the voting age even further? This episode was reported and produced by Julia Longoria and Sarah Qari. Check out Latif Nasser's new Netflix show Connected here. Support Radiolab today at Radiolab.org/donate.