In Vitro Differentiated Human Stem Cell-Derived Neurons Reproduce Synaptic Synchronicity Arising during Neurodevelopment

Summary Neurons differentiated from induced pluripotent stem cells (iPSCs) typically show regular spiking and synaptic activity but lack more complex network activity critical for brain development, such as periodic depolarizations including simultaneous involvement of glutamatergic and GABAergic neurotransmission. We generated human iPSC-derived neurons exhibiting spontaneous oscillatory activity after cultivation of up to 6 months, which resembles early oscillations observed in rodent neurons. This behavior was found in neurons generated using a more “native” embryoid body protocol, in contrast to a “fast” protocol based on NGN2 overexpression. A comparison with published data indicates that EB-derived neurons reach the maturity of neurons of the third trimester and NGN2-derived neurons of the second trimester of human gestation. Co-culturing NGN2-derived neurons with astrocytes only led to a partial compensation and did not reliably induce complex network activity. Our data will help selection of the appropriate iPSC differentiation assay to address specific questions related to neurodevelopmental disorders.
Graphical Abstract
Highlights • Spontaneous oscillatory activity in iPSC-derived neurons after 4–6 months in culture • The activity resembled early oscillations seen in rodent neurons during development • Cell growth affects developmental changes of neuronal excitability • Biological age of neurons is determined based on electrophysiological activity
Rosa and colleagues have used two neural differentiation protocols to obtain induced pluripotent stem cell-derived neuronal cultures and address their relevance for the modeling of neurogenetic disorders. In neurons generated using one of the approaches, they report spontaneously occurring oscillations with properties corresponding to the neuronal activity seen during rodent and human brain development.