Possible Link to Autism
Protein malfunction affects synapses tied to learning and memory
A clue to the causes of autism and mental retardation lies in synapses in our brains, the tiny intercellular junctions that rapidly transfer information from one neuron to the next. Tufts researchers have found that a protein called APC (adenomatous polyposis coli) plays a key role in synapse maturation, and that APC dysfunction prevents the synapse function required for typical learning and memory.
“Both sides of the synapse are finely tuned for efficient transmission; an imbalance on either side can negatively impact function, resulting in cognitive deficits,” says senior author Michele H. Jacob, a professor of neuroscience at the School of Medicine. The study found that APC plays a key role in “ensuring that the two sides of the synapse mature in concert to provide optimal function,” says Jacob, who is also a faculty member at the Sackler School of Graduate Biomedical Sciences.
The findings, which were published in the August 18 issue of The Journal of Neuroscience, “provide new insights into the mechanisms required for proper synapse function, as well as molecular changes at the synapse that likely contribute to autistic behaviors and learning deficits in people with APC loss of function gene mutations,” says Jacob.
The research team’s next step is to examine the behavioral and cognitive changes that occur when APC is deleted in neurons of the mammalian brain. They have developed a new mouse model that will allow them to investigate how the loss of APC function leads to synaptic changes and impaired learning and memory.