This project successfully addressed its main objectives, advancing our understanding of how inhibitory neurons acquire their distinct identities during brain development. By combining molecular lineage tracing, single-cell genomics, and functional perturbation approaches, we investigated the genetic and regulatory mechanisms that shape inhibitory neuron diversity.
A key achievement was the development of genetic barcodes to reconstruct the lineage relationships of inhibitory neurons. By introducing unique molecular barcodes into progenitor cells, we were able to track how their descendant neurons diversified into distinct subtypes. This approach provided new insights into the extent to which inhibitory neuron identity is influenced by lineage relationships versus regulatory programs that act as neurons mature (Bandler et al., Nature, 2022; Bandler et al., Current Opinion in Neurobiology, 2023).
To define the molecular mechanisms underlying inhibitory neuron differentiation, we applied single-cell transcriptomic and functional perturbation approaches to identify key transcription factors and gene regulatory elements that govern fate decisions. By integrating genetic perturbations with single-cell sequencing, we mapped transcriptional programs that control inhibitory neuron fate and identified enhancers that activate lineage-specific gene expression. These findings refine our understanding of how combinatorial transcription factor interactions drive inhibitory neuron diversity, with a particular focus on differential transcription factor binding to determine lineage-specific gene expression (Dvoretskova et al., Nature Neuroscience, 2024).
We also examined the role of neuronal activity in inhibitory neuron development by selectively altering membrane potential. Our results indicate that, in contrast to excitatory neurons, inhibitory neuron maturation is less dependent on membrane potential changes during early differentiation (Bright et al., BioRxiv, 2025).
The findings of this project contribute to both basic neuroscience and the study of neurodevelopmental disorders by providing insights into how inhibitory neuron diversity emerges. Since inhibitory neuron dysfunction is implicated in conditions such as autism and schizophrenia, understanding the mechanisms underlying their development may help inform future research on these disorders. The results have been published in peer-reviewed journals, presented at international conferences, and shared with other research groups. The methodologies and genetic tools developed here are now being applied in diverse biological systems, including studies on brain tumors and non-mammalian models. Through these efforts, this project has established a foundation for further studies on inhibitory neuron development and its broader implications in neuroscience.
