Abstract: Loss of neurons and disruption of neural circuits are associated with many neurological diseases, including neurodegenerative diseases and mental disorders. The most prevalent pathological feature of neurodegenerative diseases is the aggregate loss of certain neuronal populations. For example, the loss of dopamine (DA) neurons in the substantia nigra pars compacta has been defined as a pathological hallmark of Parkinson’s disease (PD; Kamath et al., 2022). Therefore, methods to reverse neuronal reduction in an effort to rebuild neural circuits and improve function have become an important research focus. In the past decade, regenerative medicine has taken a momentous leap forward with a groundbreaking discovery in the field of neuroregeneration. In vivo glia-to-neuron conversion therapy has presented itself as a potential solution (Qian et al., 2020). This is a paradigm-shifting regenerative strategy to reprogram resident glial cells in situ into neurons in vivo (Figure 1). This method is obviously superior to the strategy of inducing stem cells to differentiate into neurons in vitro for in vivo transplantation, avoiding various problems, such as difficult integration, cancer degeneration, and immunogenicity. However, the evidence supporting the replacement of lost neurons with trans-differentiated cells and\ the reconstitution of neuronal circuits remains limited.