In Mouse Model of Autism, Atypical Vocalizations Reduce Maternal Care
In Mouse Model of Autism, Atypical Vocalizations Reduce Maternal Care
For an infant, crying is an effective form of communication, reliably summoning a parent in times of need. But new research in mice suggests that a genetic abnormality associated with autism alters the patterns of early vocalizations, making them less effective at eliciting a mother's care.
Other studies have shown that the cries of infants who are later diagnosed with autism spectrum disorders have rhythms and pitches that are different from the cries of typically developing babies. The mouse research, partially funded by BBRF and published December 15 in the journal Molecular Psychiatry, suggests that such communication deficits might contribute to later social impairments by weakening parental care during early development.
The research was led by NARSAD 2006 Independent Investigator and 1998 NARSAD Young Investigator Noboru Hiroi, Ph.D., at Albert Einstein College of Medicine.
For their study, the researchers studied mice lacking one copy of a gene called Tbx1. In humans, Tbx1 is one of about 30 genes affected by the loss of a genetic region known as 22q11.2, a rare genetic event that is strongly associated with autism spectrum disorder. Mice missing a copy of Tbx1 exhibit a range of autism symptoms, including reduced social interaction and fewer vocalizations during early life.
The researchers recorded and analyzed the calls of the mouse pups when they were 8 to 12 days old, a developmental period that corresponds to that of a newborn human. They discovered that while normal mice use diverse, sometimes complex calls at this age, the calls of the mice with Tbx1mutations were simpler and more uniform.
What's more, mother mice were less likely to respond to the calls of mice with Tbx1 mutations than they were to the calls of typical mouse pups. The scientists recorded the calls and played them from an emitter: normal calls caused mothers to peek through a tube and approach the source of the sound, whereas the same mothers showed little interest in calls recorded from pups with Tbx1 mutations.
Further research is needed to understand the cause and impact of atypical cries in infants with autism spectrum disorders, but recognizing these patterns could help caregivers respond in ways that improve outcomes, the scientists say.
