Early disruptions in serotonin signaling in the brain may
contribute to autism spectrum disorder (ASD), and other
"enduring effects on behavior," Vanderbilt University
researchers report. Serotonin is a brain chemical that carries
signals across the synapse, or gap between nerve cells. The
supply of serotonin is regulated by the serotonin transporter
(SERT). In 2005, a team of Vanderbilt researchers led by Randy
Blakely and James Sutcliffe identified rare genetic variations
in children with ASD that disrupt SERT function. In a new study
published this week in the Proceedings of the National Academy
of Sciences (PNAS), the researchers report the creation of a
mouse model that expressed the most common of these variations.
The change is a very small one in biochemical terms, yet it
appears to cause SERT in the brain to go into "overdrive" and
restrict the availability of serotonin at synapses. "The SERT
protein in the brain of our mice appears to exhibit the
exaggerated function and lack of regulation we saw us