Nerve cells communicate with each other at specialized contact points, the synapses. When stimulated, a transmitting nerve cell emits neurotransmitters. These signal molecules reach the receiving cell and affect its activity status - provided the receiving cell has "aerials" on its synapses - receptors that bind the chemical signals. The scientists speculated that this process could be disrupted if the nerve cells have no neuroligins.
At the time of BourgeronTM's discovery, Nils Brose and Frederique Varoqueaux, brain researchers at the Max Planck Institute for Experimental Medicine in Göttingen, in collaboration with colleagues Weiqi Zhang from the neighbouring University Hospital and US geneticist Thomas Südhof, had already been working on neuroligins for ten years - however in mice, not in humans. "We had even already created mutant mice which, in functional terms, were carrying the same mutations as occur in autistic patients. Our mice were also lacking either neuroligin-3 or neuroligin-4," says Brose. The researchers were in possession of the first genetic animal model for autism.
A study published by Brose, Varoqueaux and Zhang in the specialist journal Neuron has shown that this model exhibited a malfunction in the signal transmission between the nerve cells. With his colleague Varoqueaux, Brose has created a mouse line that not only lacked neuroligin-1 or neuroligin-2, both of which have been associated with autism, but were missing all four known variants of the protein simultaneously. The consequence