According to a report published on today, in the open-access journal PLoS Genetics, the regulation of neural framework in the brain is dependent on the gene Forkhead box protein P2 (Foxp2), a gene that is involved in speech and language. To recognize this important link, the scientists first pinpointed the main targets of Foxp2 in developing brain tissue and then analysed the role of specific neurons.
The protein that Foxp2 gene codes for is regulatory in function and allows us to understand unfamiliar aspects of the brain. In humans, mutations of Foxp2 cause a severe speech and language disorder. This was discovered by scientists in the year 2001. Since then, extensive research has been carried out about this human gene and related genes found in other species. Different versions of the Foxp2 gene have been found to exist in similar forms in distantly related vertebrates. Functional studies of the gene in mice and in songbirds indicate that it is important for modulating plasticity of neural circuits.
Dr. Sonja C. Vernes and Dr. Simon E. Fisher (The Wellcome Trust Centre for Human Genetics, University of Oxford), were the lead scientists for the current study in which they gained significant understanding about the functions of Foxp2 within the developing brain. They made use of the genes role as a genetic dimmer switch by increasing or decreasing the amount of material made by other genes. Numerous novel targets regulated by Foxp2 were recognized by the scientists during their large-scale screening of embryonic brain tissue, many of which were known to play important roles for connectivity of the central nervous system.
Upon altering the levels of Foxp2 the researchers were able to demonstrate an impact on the length and branching of neuronal projections. These neuronal projections are the primary mechanism by which the neural framework of the brain develops. Dr. Fisher, who in addition to being the lead author of the study also serves as the director of a newly established Language and Genetics department at the Max Planck Institute for Psycholinguistics, The Netherlands, said,
"Studies like this are crucial for building bridges between genes and complex aspects of brain function."
Mouse models were utilized to conduct the research since they can be used to analyse genetic networks in detail, in a way that remains difficult in the human brain. However,
"the current study provides the most thorough characterisation of Foxp2 target pathways to date,"
commented Dr. Fisher.
"It offers a number of compelling new candidate genes that could be investigated in people with language problems."
"Foxp2 Regulates Gene Networks Implicated in Neurite Outgrowth in the Developing Brain"
Vernes SC, Oliver PL, Spiteri E, Lockstone HE, Puliyadi R, et al. (2011)
PLoS Genet 7(7): e1002145. doi:10.1371/journal.pgen.1002145
Written by Barry Windsor