Long-term calcium imaging reveals functional development in hiPSC-derived cultures comparable to human but not rat primary cultures

Models for human brain-oriented research are often established on primary cultures from rodents, which fails to recapitulate cellular specificity and molecular cues of the human brain. Here we investigated whether neuronal cultures derived from human induced plurip-otent stem cells (hiPSCs) feature key advantages compared with rodent primary cultures. Using calcium fluorescence imaging, we tracked spontaneous neuronal activity in hiPSC-derived, human, and rat primary cultures and compared their dynamic and functional behavior as they matured. We observed that hiPSC-derived cultures progressively changed upon development, exhibiting gradually richer activity patterns and functional traits. By contrast, rat primary cultures were locked in the same dynamic state since activity onset. Human pri-mary cultures exhibited features in between hiPSC-derived and rat primary cultures, although traits from the former predominated. Our study demonstrates that hiPSC-derived cultures are excellent models to investigate development in neuronal assemblies, a hallmark for applications that monitor alterations caused by damage or neurodegeneration.

Automated summary

Models for human brain-oriented research often rely on rodent primary cultures, which lack cellular specificity and molecular cues. In this study, we compared human induced pluripotent stem cell (hiPSC)-derived cultures with rat primary cultures for their dynamic and functional behavior. We found that hiPSC-derived cultures exhibited progressively richer activity patterns and functional traits during development, making them excellent models for studying neuronal assembly development and monitoring alterations caused by damage or neurodegeneration.