In an era when researchers make entire teeth from a few cells or breasts from fatty tissue, nothing should amaze us.

But scientists from Université Laval's Faculty of Medicine have managed to create "in vitro" neurons, the nerve cells the brain is made of, employing stem cells they took from adult human skin. "This is the first time such an advanced state of nerve cell differentiation has been achieved from human skin," said lead researcher Professor François Berthod.

This is a scientific breakthrough, that could eventually speed the finding of advanced treatments for neurodegenerative illnesses such as Parkinson's disease, Alzheimer's and others.

The French team employed skin tissue achieved from plastic surgery procedures. The researchers selected from the skin tissues neuron precursor cells, which were then cultivated "in vitro". There are no neurons in the skin, there are only their extensions, called dendrites (with sensitive purpose) and eventually axons (that transmit commands to cutaneous muscles).

Neurons are harbored inside the brain and spinal cord. The scientific challenge was to generate neurons from undifferentiated cells rather than from other neurons.

The team proved that stem cells achieved from the skin can multiply and differentiate "in vitro" when they encounter the appropriate environment. They progressively developed on neurons, taking the typical neuronal oblong shape. In a few days, the cells started synthesizing markers and chemicals linked to the interneuronal transmission of the impulse. "This suggests the beginning of synapse formation between neurons," said Berthod.

This research is a significant breakthrough in neuroscience. "Producing neurons from skin cells could solve the problem of human neural cell availability for research," explains Berthod.

"Since neurons do not multiply, researchers now have to rely on laboratory animal neurons to perform their experiments. We could take a patient's skin cells and use them to produce perfectly compatible neurons, thus eliminating the risk of rejection. We could then transplant these nerve cells in the diseased areas of the brain," explains Berthod.

"This type of procedure seems particularly interesting for diseases such as Parkinson's, but it's all theoretical for now. Before we can think of doing such things, we'll have to improve nerve cell differentiation and prove that they can transmit nerve impulses," added Berthod.