Gene critical for brain development discovered

Toronto, June 22 (IANS) Researchers have discovered the gene that is responsible for the proper development of a healthy cerebellum.

The gene called "Snf2h" is responsible for the development of the cerebellum - the master control centre in the brain for balance, fine motor control and complex physical movements.

When researchers 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 neuro-degenerative 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 David Picketts, senior scientist at Ottawa Hospital Research Institute in Canada.

"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 formation of a neuron that does not perform very well," Picketts added.

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.

"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," said Picketts.

The findings were published in the journal Nature Communications.