Researchers at MIT generated a new atlas of the striatum, identifying 31 distinct subgroups of neurons based on the genes they express using single-cell RNA sequencing. ^[1] Bryan Roth, one of the inventors of chemogenetics, said at the BRAIN Initiative conference on 2026-08-13 that he had identified seven ongoing clinical trials of chemogenetics in China. ^[2] Myriam Heiman, the Picower Professor of Neuroscience at MIT, stated that the atlas serves as a foundation for future studies on Huntington's disease and opioid use disorder. ^[3] The research found that dorsal populations of medium spiny neurons express higher levels of the genes MSH2 and MSH3, which increase the number of CAG repeats in the huntingtin gene associated with Huntington's disease. ^[4] The study identified two specific 'outlier' populations of medium spiny neurons, known as D1 and D2 outliers, which are involved in addiction, depression, and schizophrenia. ^[5] Chemogenetics works by engineering neurons to express designer receptors (DREADDs) that can be activated by normally inert drugs, allowing specific brain cells to be excited or inhibited. ^[6] The seven clinical trials that Bryan Roth identified in China are targeting pain, Parkinson's disease, and epilepsy. ^[7]