Two genes key to wiring brain’s nerve cells

LONDON - Scientists have now been able to show that growing nerve cells realise when they’ve reached their target area in the brain — thanks to the interaction of two genes.

Each of the nerve cells — of which there are about 100 billion in the human brain — is programmed to connect to specific other cells in order to form a fully functional organism.

Neurobiologists from Max Planck Institute of Neurobiology in Germany and Kyoto in Japan analyzed the function of these genes that play a role in the development of the fruit fly’s visual system, the journal Nature Neuroscience reports.

These two genes produce proteins “Golden Goal” and “Flamingo”, located at the tip of a growing axon, the cell’s connecting cable. Their actions enable nerve cells to find their way in the brain and recognize their target area, according to a Max Planck statement.

Once the axon has reached its target area, it connects itself with the local nerve cells. In this way a processing chain is established which allows us, for example, to see a cup, recognize it as such, reach out and take hold of it.

Had there been a mismatch between the nerve cells, it would be impossible to reach the coffee in the cup.

The study showed that chaos results if only one of the genes is active, or if there is a mismatch in the genes’ activity — the axons cease to grow somewhere along the way and never reach their target area.

“We assume that very similar mechanisms play a role also in other organisms - including humans,” explains Takashi Suzuki, study’s lead author.