Columbia University Medical Center has just published some interesting research. Dr Tang looked at 46 children's brains and found that whilst the number of synapses in an non autistic child's brain decreased by about half by adolescence they decreased by only 16% in the brains of a person with autism.
The forming and pruning of synapses is the heart of the dynamic process of neuroplasticity. The pruning of less used synapses is crucial in making our neurological pathways more efficient. It goes on everyday as we go about our lives but there is massive synapse creation and then pruning in childhood and adolescence. If your brain doesn't prune effectively then this would have profound effects on how you experience the world and learn. So this kind of research has the potential to tell us a lot about the experience of someone with autism.
Dr Tang's team tried an immunosuppressant drug called rapamycin on mice and found that it helped pruning and led to a reduction in repetitive behaviours. The problem is that "the drug has really horrible side effects."
There has been a lot of work done on how to strengthen learning by creating new synaptic connections but Dr Tang's research suggests that it's time we directed more attention to pruning.
What helps and enables effective pruning and what is particular about autism that stops the synapses from dying back? Is the reduced amount of pruning a cause of the autistic condition or a reflection of it?
It has also got us thinking about how HANDLE activities may be assisting pruning. It would be wonderful to see more research into the role of nutrition, hydration and rhythmic, organising movement alongside research into a drug that brings its own set of problems.