Schizophrenia often occurs during late adolescence or early adulthood and is characterized by cognitive problems such as delusions and hallucinations. About 1.1 % of Americans are affected by schizophrenia every year. Despite schizophrenia being so common and having many treatments, there are still unanswered questions. One question in particular is the origin of auditory hallucinations.
Researchers at St. Jude Children's Research Hospital have been using mouse models in order to replicate genetic predisposition for schizophrenia. The model that researchers were studying in particular is the 22q11 deletion syndrome, also known as DiGeorge syndrome. By modeling this syndrome, it allows the researchers to observe the development of psychiatric conditions, some of which that lead up to the development of schizophrenia.
While running the mouse model, scientists have identified microRNAs that can be served as useful for creating new anti-psychotic drugs with reduced side effects. MircoRNAs are non-coding RNA molecules that generally involved in regulating and silencing gene expression. The specific microRNA that is of particular interest to researchers is miR-338-3p. This specific microRNA regulates the manufacture of protein D2 dopamine receptor (DRd2) in which have a major role in auditory hallucinations. According to Dr. Zakharenko, auditory hallucinations that are typical in schizophrenia is related to high levels of Drd2 in the auditory thalamus.
Through the mouse modeling, the researchers have discovered that individuals with 22q11 deletion syndrome are missing Dgcr8 genes in which is essential for the production of microRNAs. Because of the reduction of Dgcr8 genes based on this study, this leads to an increase in DrD2, thus causing auditory hallucinations demonstrated from schizophrenia. Further results have concluded that by replenishing microRNAs, the Drd2 levels decreased thus restoring normal functioning within the auditory thalamus, thus leading to a cure to auditory hallucinations. This is an important breakthrough for anti-psychotic drugs. By using a natural process and the concepts of microRNA, it can serve a new basis for how drugs for treating mental disorders are made. In particular, the benefits of microRNA is that it can lead to more effective interventions with limited side effects. With such an important discovery, this research can pave the way to tacking other mental disorders using the same concept. It will be very interesting to see how this research will progress and be beneficial in terms of psychiatric and medical research.