TUESDAY, Feb. 12 (HealthDay News) -- The lack of a particular
brain protein may explain the phenomenon of "Rain Man" -- autistic
savants who learn some tasks better but also forget faster, say
researchers at Massachusetts Institute of Technology.
Mice genetically engineered to lack a key protein used for
building synapses -- the junctions through which brain cells
communicate -- actually learned a spatial memory task faster and
better than normal mice, according to findings in the Feb. 13 issue
of the
Journal of Neuroscience. But when tested weeks later, the
altered mice couldn't remember what they had learned as well as
normal mice, and they had trouble remembering contexts that should
have provoked fear.
"These opposite effects on different types of learning are
reminiscent of the mixed features of autistic patients, who may be
disabled in some cognitive areas but show enhanced abilities in
others," study co-author Albert Y. Hung, a staff neurologist at
Massachusetts General Hospital, said in a prepared statement. "The
superior learning ability of these mutant mice in a specific realm
is reminiscent of human autistic savants."
The absence of this important synaptic scaffold protein, called
Shank1, may "trap" the mice's synapses into a state in which the
synapses are ready to respond to input but not maintain it in
long-term memory, he said.
In humans, mutations in the closely related protein Shank3 have
been linked to the autism spectrum of disorders (ASD) characterized
by impaired social interaction, absent or delayed language
development and repetitive behaviors. Occasionally, an autistic
person has an outstanding skill, such as an incredible rote memory
or musical ability. Such individuals, like the character Dustin
Hoffman played in the film "Rain Man," may be referred to as
autistic savants.
More information
The National Dissemination Center for Children with Disabilities
has more about
autism.
