Gene critical for brain development identified

Written by PTI | Toronto | Updated: Jun 23 2014, 01:16am hrs
Researchers have identified a gene which is required for the proper development of a healthy cerebellum, a master control centre in the brain for balance, fine motor control and complex physical movements.

Researchers have found that a specific gene, called Snf2h, plays an important role in the development of the cerebellum.

Athletes and artists perform their extraordinary feats relying on the cerebellum. The cerebellum is critical for the everyday tasks and activities that we perform, such as walking, eating and driving a car.

By removing Snf2h, researchers found that the cerebellum was smaller than normal, and balance and refined movements were compromised.

Led by Dr David Picketts, a senior scientist at the Ottawa Hospital Research Institute and professor in the Faculty of Medicine at the University of Ottawa, the team described the Snf2h gene, which is found in our brain's neural stem cells and functions as a master regulator.

When they removed this gene early on in a mouse's development, its cerebellum only grew to one-third the normal size.

It also had difficulty walking, balancing and coordinating its movements, something called cerebellar ataxia that is a component of many neurodegenerative diseases.

"As these cerebellar stem cells divide, on their journey toward becoming specialised neurons, this master gene is responsible for deciding which genes are turned on and which genes are packed tightly away," said Picketts.

"Without Snf2h there to keep things organised, genes that should be packed away are left turned on, while other genes are not properly activated.

"This disorganisation within the cell's nucleus results in a neuron that doesn't perform very well - like a car running on five cylinders instead of six," he said.

The cerebellum contains roughly half the neurons found in the brain. It also develops in response to external stimuli. So, as we practice tasks, certain genes or groups of genes are turned on and off, which strengthens these circuits and helps to stabilise or perfect the task being undertaken.

The researchers found that the Snf2h gene orchestrates this complex and ongoing process. These master genes, which adapt to external cues to adjust the genes they turn on and off, are known as epigenetic regulators.

"These epigenetic regulators are known to affect memory, behaviour and learning," said Picketts.

"Without Snf2h, not enough cerebellar neurons are produced, and the ones that are produced do not respond and adapt as well to external signals.

"They also show a progressively disorganised gene expression profile that results in cerebellar ataxia and the premature death of the animal," he said.

The study was published in the journal Nature Communications.