Serotonin-specific neurons differentiated from human iPSCs form distinct subtypes with synaptic protein assembly

Area of Science:

• Neuroscience
• Stem Cell Biology
• Neurobiology

Background:

• Human induced pluripotent stem cells (hiPSCs) offer potential for disease modeling.
• Developing protocols for specific neuronal subtypes, like serotonin (5-HT) neurons, remains challenging.
• 5-HT system dysfunction is linked to neuropsychiatric disorders, but in vitro models are limited.

Purpose of the Study:

• To establish an efficient protocol for generating functionally active, 5-HT-specified neurons from hiPSCs.
• To characterize these hiPSC-derived 5-HT neurons using advanced imaging and electrophysiology.
• To assess the potential of these neuronal cultures for studying neuropsychiatric disorders.

Main Methods:

• Modification of existing protocols for hiPSC differentiation.
• Characterization using super-resolution fluorescence microscopy.
• Electrophysiological recordings to assess neuronal activity and function.
• Analysis of specific serotonin neuron markers (e.g., TPH2, SERT) and synaptic proteins (e.g., Bassoon, Homer).

Main Results:

• Efficient generation of hiPSC-derived neurons with 5-HT specification (~42%).
• Neurons exhibited characteristic serotonergic electrophysiological properties and synthesized 5-HT.
• Expression of key markers (TPH2, SERT) and synaptic proteins (Bassoon, Homer) confirmed neuronal identity and function.
• Identification of a CDH13+ subpopulation, potentially representing dorsal raphe neurons.

Conclusions:

• The developed protocol efficiently generates functional, 5-HT-specific neurons from hiPSCs.
• These hiPSC-derived neurons accurately model aspects of human serotonergic systems.
• The findings facilitate the study of serotonergic neuron subpopulations in neuropsychiatric disorders.