Dear Editor,

Here, we present a method to accelerate the differentiation of γ-aminobutyric acid (GABA) interneurons (GINs) from human pluripotent stem cells (hPSCs). Normal brain function requires balanced levels of excitation and inhibition of neurotransmitter. GINs are the main inhibitory neurons in the central nervous system, and they are thought to play a critical role in sculpting inhibitory network dynamics in the cerebral cortex (Rossignol, 2011). Thus, dysfunction of GINs induces many neurological diseases, such as epilepsy, major depression, anxiety, and autism. Since it is difficult to recover from the dysfunction/loss of GINs in the neural network, exogenous GIN transplantation has been considered a potential therapeutic strategy for the treatment of GIN-associated neurological diseases. Although reported methods offer various ways to differentiate high-purity human GINs from hPSCs, it still takes >1 month to obtain a high proportion of GINs (Table 1). Moreover, the protracted timing of human GIN specification and subtype maturation remains a key challenge that hampers the routine application of hPSC-derived lineages in disease modeling and regenerative medicine studies. Additionally, the current differentiation method mainly relies on co-culture with rodent cortical neurons/astrocytes and cell sorting, which limits the application of human GINs for cell transplantation and therapy. Therefore, it is urgent to establish a time- and cost-effective, highly efficient non-xenogenic differentiation system for differentiating human GINs. Here, we sought to identify small molecule (SM)-based conditions that accelerate the differentiation of human GINs without adding any components with heterologous origins or performing genetic manipulations.