Scientists have discovered how mutations in two key proteins may lead to autism. http://www.neuron.org/content/article/abstract?uid=PIIS0896627307004096&highlight=kavalali The proteins - neuroligin-1 and neuroligin-2 - create a physical bridge at the junction - or synapse - of nerve cells, enabling them to make connections with others. In studies on rats the researchers showed that raising levels of both proteins in nerve cells led to the creation of extra synapses. Neuroligin-1 was associated with excitatory connections and neuroligin-2 with inhibitory connections. When they introduced a mutant form of neuroligin-1 thought to be carried by some people with autism the number of synapses fell dramatically - and the cells became significantly less excitable. Infants are born with far more synapses than survive to adulthood. Active synapses proliferate during development, but inactive synapses are culled. The latest research suggests that carrying a mutant form of neuroligin-1 may depress the number of synapses that make it into adulthood. This could hamper the ability of nerve cells to make the usual connections, and lead to the deficits seen in people with autism. It affects the way a person communicates and interacts with other people. http://news.bbc.co.uk/2/hi/health/6221064.stm
