Astrocytes are star-shaped support cells (astrum = star), which are mainly important for supplying neurons with all necessary substances from glucose to water, but they also play a major role in repair processes and, as is now being shown, can with pharmacological support help to influence stuttering.
The striatum is a region of deep gray matter in the brain, and its main significance lies in the regulation of voluntary movements.
Stuttering that appears in childhood is associated with an excess of the neurotransmitter dopamine in the striatum. The antipsychotic called risperidone lowers the amount of dopamine in the brain and is used in the treatment of disorders caused, among other things, by excess dopamine. Scientists at Riversade University in California and the U.S. National Institute of Health found that administration of risperidone leads to increased activity of astrocytes in the striatum and thus lowers dopamine concentrations and improves verbal output in affected people.
"We do not know the exact mechanism by which risperidone activates astrocytes in the striatum," said SheikhBahaei, a co-author of the study, an astrocyte expert and a person who stutters himself. "We know that it activates astrocytes. The astrocytes then release a signaling molecule that affects neurons in the striatum by blocking their dopamine receptors. In our future work we would like to find this signaling molecule and better understand the exact role that astrocytes play in stuttering, which could again help us to design drugs targeting astrocytes."
"In the stuttering community I have been involved for decades," said the lead author of the study, Dr. Gerald A. Maguire. "This is a community that needs support, opportunities, and role models. Dr. SheikhBahaei and I encourage people who stutter to become more involved in the scientific community. Both of us stutter, and this did not prevent us from achieving our professional and personal goals. Young people who stutter and are considering a career in science and medicine should not be discouraged by this speech disorder."
Author: MUDr. Radkin Honzák psychiatrist
Gerald A. Maguire, Bo Ram Yoo, Shahriar SheikhBahaei: Investigation of Risperidone Treatment Associated With Enhanced Brain Activity in Patients Who Stutter. Frontiers in Neuroscience, 2021; 15 DOI: 10.3389/fnins.2021.598949