Researchers have discovered a link between two human-specific genes, SRGAP2B and SRGAP2C, and the gene SYNGAP1, which is associated with intellectual disability and autism spectrum disorders. The study found that these genes slow down synapse development in humans, a process thought to contribute to advanced learning abilities.
By turning off these genes in human neurons, scientists observed accelerated brain connectivity development, mimicking changes seen in certain neurodevelopmental conditions. This finding suggests that genes contributing to human brain evolution may also influence susceptibility to brain disorders.
Future research aims to explore how these genes impact learning and could become targets for new treatments. The study provides valuable insights into why certain neurological conditions are more common in humans.
In the human brain, synapses – critical connections between neurons – take years to mature, compared to months in other species. This prolonged development, known as neoteny, is thought to be central to humans’ advanced cognitive abilities.
However, disruptions of this process may explain some neurodevelopmental diseases. The team of researchers found that SRGAP2B and SRGAP2C slow down synapse development when artificially introduced into mouse neurons. They then tested these genes in human neurons, switching off SRGAP2B and SRGAP2C to observe accelerated brain connectivity development.
The study reveals that the SRGAP2 and SYNGAP1 genes act together to control the speed of human synapse development. Most strikingly, they found that SRGAP2B and SRGAP2C increase the levels of the SYNGAP1 gene, which can even reverse some defects in neurons lacking SYNGAP1.
This finding increases our understanding of how human-specific molecules influence neurodevelopmental disease pathways, shedding light on why such disorders are more prevalent in humans. The researchers believe that this work could lead to innovative drug targets and a better understanding of how human-specific mechanisms of brain development affect learning and behavior.
Source: https://neurosciencenews.com/autism-genetics-neurodevelopment-27858/