Neuroligin Mutations as a Cause of Autism

A study published in the September 21st issue of Neuron 51, 741-754 (2006), suggests that mutations in neuroligins, which ensure that signal transitions between nerve cells function, can result in a malfunction in synapses maturing. A mutation in the genes which contain the “blueprint” for proteins in the neuroligin family can be linked to causing autism in humans, according to brain researchers at the Max-Planck-Institute for Experimental Medicine.

With his colleague [Frederique] Varoqueaux, [Nils] 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 consequences are accordingly more drastic than with autistic patients, who only have one mutated neuroligin gene. Without any neuroligins, the function of the nervous system breaks down completely and the mutant animals die immediately after birth. However, their nerve cells can be examined in detail. According to Brose, “they deliver important findings not only for brain research in general, but also for the possible causes of autism. Our investigations show that the neuroligins regulate the maturation of the synapses. They ensure that there are sufficient receptor proteins on the synaptic membrane of the receiving cell.”

Go here to read a summary of this research at Physorg.com.