It is believed that stuttering results from defects in brain circuits in those areas that regulate language but the precise areas where these disorders occur or which cells are actually involved are not yet well known. Now, a new step has been taken by a group of researchers.
In a study published in the Proceedings of the National Academy of Sciences, researchers from the National Institute of Deafness and Other Communication Disorders (NIDCD) announce that they have discovered which brain cells are linked to stuttering in mice. In the laboratory experiments, the same rodents had undergone a modification of the GNPTAB gene so that they acquired the mutation of the human gene linked to stuttering.
Mice with this modified gene showed pauses in the flow of vocalizations, similar to those that characterize stuttering in people. They also showed no other defects other than language-related, just like in humans.
The researchers found that in the brains of these rodents there was a decrease in astrocytes, a support cell present in the brain, in the corpus callosum, an area of the brain tissue that connects the two hemispheres.
Dennis Drayna, a researcher with the NIDCD who led the study, states: “By adopting a genetic approach, we were able to begin to decipher the neuropathology of stuttering, first at the molecular level by identifying genetic mutations and now at the cellular level,” underlining how much this study is even more important than the studies carried out with brain imaging on people who stutter.
In the same vein it is also the intervention of Andrew Griffith, scientific director of the NIDCD: “Perhaps more importantly, to identify the region of the brain and the cells involved opens up opportunities for new interventions for stuttering and possibly other language disorders.”
The same team had previously identified certain genes associated with stuttering.