Dysregulated protein synthesis at the synapse of brain neurons is a common feature of autism spectrum disorders, including Fragile X Syndrome.

In a study published online on June 20 in Neuron, Pablo Castillo, M.D., Ph.D., and colleagues have uncovered a novel mechanism that may contribute to those disorders. The researchers studied the mossy fiber-CA3 synapse, which helps to store new information and to retrieve previously stored information; the synapse also expresses both structural and functional presynaptic plasticity and contains Fragile X messenger ribonucleoprotein (FMRP), an RNA-binding protein involved in postsynaptic protein synthesis. They found that presynaptic FMRP and local protein synthesis dynamically control presynaptic structural and functional plasticity at excitatory presynapses in the mature mammalian brain, and that loss of FMRP function in the presynapse may contribute to the pathology of Fragile X Syndrome and autism.

Dr. Castillo is professor of psychiatry and behavioral sciences, and in the Dominick P. Purpura Department of Neuroscience, as well as the Harold and Muriel Block Chair in Neuroscience at Einstein.