Washington: A new study has shown for the first time how two tiny molecules regulate a gene implicated in speech and language impairments as well as autism disorders, and that social context of vocal behaviour governs their function.
Because the vocal learning process in birds has many similarities with speech and language development in humans, the zebra finch provides a useful model to study the neural mechanisms underlying speech and language in humans.
Mutations in the FOXP2 gene have been linked to speech and language deficits and in autism disorders.
A current theory is that a precise amount of FOXP2 is required for the proper development of the neural circuits processing speech and language, so it is important to understand how the FOXP2 gene is regulated.
The research led by Xiaoching Li, PhD, at the LSU Health Sciences Center New Orleans Neuroscience Center of Excellence, identified two microRNAs, or miRNAs, - miR-9 and miR-140-5p - that regulate the levels of FOXP2.
The researchers showed that in the zebra finch brain, these miRNAs are expressed in a basal ganglia nucleus that is required for vocal learning, and their function is regulated during vocal learning. More intriguingly, the expression of these two miRNAs is also regulated by the social context of song behavior - in males singing undirected songs.
"Because the FOXP2 gene and these two miRNAs are evolutionarily conserved, the insights we obtained from studying birds are highly relevant to speech and language in humans and related neural developmental disorders such as autism," Xiaoching Li said.
The study is published in The Journal of Neuroscience.