Surplus synapses ‘may cause autism’

The surplus synapses – places where neurons connect and communicate – are due to a lack of “pruning” that normally occurs early in life.

In mice with autistic traits, scientists at Columbia University in New York were able to restore synaptic pruning and reduce symptoms with a drug used to suppress the immune systems of transplant patients.

The drug, rapamycin, has side-effects that make it unsuitable as an autism treatment, but the discovery opens up possibilities for other therapies based on synaptic pruning.

The National Autistic Society welcomed the research, but stressed a suggestion that a drug could be developed to tackle autism should be “treated with caution”.