New research has uncovered a potential reason why some people develop intellectual disabilities or autism – the accelerated maturation of brain cells. Scientists have long understood that neurons, especially in the cerebral cortex region responsible for advanced cognitive functions, normally take years to fully develop in humans through a process called “neoteny”. However, a recent study suggests that genetic mutations which disrupt this prolonged development cycle could underlie certain forms of intellectual disability and autism.
The study, published in the journal Neuron, focused on the gene known as SYNGAP1. According to the researchers from the Flemish Institute for Biotechnology in Belgium, this gene plays a key role in encouraging the extended maturation of brain cells. But changes or mutations to SYNGAP1 disrupt its normal function, accelerating the rate at which neurons develop connections in the brain.
To investigate this further, the scientists transplanted human neurons containing mutated SYNGAP1 genes into mouse brains. Through analysis of the connections formed, they found these mutated neurons displayed a marked speeding up of their developmental timeline. While appearing normal otherwise, they integrated into networks and responded to stimuli much earlier than usual.
This premature functionality indicates the genetic mutations are essentially causing brain cells to mature too quickly. While previous research linked SYNGAP1 alterations to intellectual disabilities, the new study sheds light on exactly how disruption to neuronal development in the brain could underlie these conditions. The findings provide crucial insights that may help with understanding, treating and preventing intellectual disabilities and certain forms of autism.
