Expanding GABAergic Neuronal Diversity in iPSC-Derived Disease Models

Area of Science:

• Neuroscience
• Stem Cell Biology
• Developmental Biology

Background:

• GABAergic interneurons are crucial for neural circuit function, and their dysfunction is linked to neurodevelopmental and psychiatric disorders.
• Current methods for differentiating human pluripotent stem cells (PSCs) into neurons face challenges like incomplete differentiation and variability.

Purpose of the Study:

• To develop an efficient strategy for generating diverse, region-specific GABAergic neuronal types from human PSCs.
• To characterize the cellular heterogeneity and regulatory mechanisms of these induced neurons (iNs).
• To model the impact of specific genetic mutations on GABAergic neuron development.

Main Methods:

• Overexpression of transcription factors ASCL1 and DLX2 combined with dual-SMAD and WNT inhibition.
• Single-cell sequencing to analyze cellular heterogeneity and gene expression.
• Application of the protocol to study an ADNP syndrome mutation.

Main Results:

• The new protocol efficiently generates diverse GABAergic iNs, including patterned iNs (resembling ganglionic eminence and neocortex) and PSC-derived iNs (resembling hypothalamic and thalamic neurons).
• Both iN types are enriched for genes associated with neurodevelopmental and psychiatric disorders.
• The ADNP syndrome mutation was shown to disrupt GABAergic fate specification and synaptic transmission.

Conclusions:

• This study provides complementary GABAergic iN models (patterned and PSC-derived) for studying distinct neuron subtypes, brain regions, and disease contexts.
• The developed protocol offers a powerful platform for investigating molecular mechanisms in neurodevelopmental and psychiatric disorders.
• These findings expand the toolkit for disease modeling using human stem cell-derived neurons.