A new study published in the journal "Frontiers in Behavioral Neuroscience" has found that ultrasonic vocal communications in adult mice is affected by the same gene needed for speech in humans.
The Forkhead Box protein 2 (FOXP2) gene regulates speech production in humans, and aberrations of this gene result in an impairment of speech production and comprehension.
"This study supports the 'continuum hypothesis,' which is that FOXP2 affects the vocal production of all mammals and not just humans," said senior author Dr. Erich Jarvis, of Duke University Medical Center, Howard Hughes Medical institute and the Rockefeller University.
26 Male mice were bred to have a deficit of FOXP2 protein equivalent to that found in humans known to have speech problems. 24 wildtype mice with a normal level of FOXP2 were also bred. The mice were then housed in a multitude of unique conditions and scenarios and their vocal patterns analyzed. Results concluded that FOXP2 heterozygotes have difficulty producing the complex vocal communication patterns that wildtype mice were able to produce with ease. This was measured both by syllable length, as well as number of unique syllables produced over time. Wildtype males were three times as likely as heterozygotes to produce the most complex syllable types and sequences available for review.
Further analysis also revealed that the heterozygotes vocal motor neurons were more widely distributed across the cortex than was the case for wildtype mice, suggesting that FOXP2 effects both the placement and functioning of neurons for effective communication, in both mice and humans.