Supplementary Material for: Low-Density Neuronal Cultures from Human Induced Pluripotent Stem Cells

Induced pluripotent stem cell (iPSC)-based technologies offer an
unprecedented possibility to investigate defects occurring during
neuronal differentiation in neuropsychiatric and neurodevelopmental
disorders, but the density and intricacy of intercellular connections in
neuronal cultures challenge currently available analytic methods.
Low-density neuronal cultures facilitate the morphometric and functional
analysis of neurons. We describe a differentiation protocol to generate
low-density neuronal cultures (∼2,500 neurons/cm2) from
human iPSC-derived neural stem cells/early neural progenitor cells. We
generated low-density cultures using cells from 3 individuals. We also
evaluated the morphometric features of neurons derived from 2 of these
individuals, one harboring a microdeletion on chromosome 15q11.2 and the
other without the microdeletion. An approximately 7.5-fold increase in
the density of dendritic filopodia was observed in the neurons with the
microdeletion, consistent with previous reports. Low-density neuronal
cultures enable facile and unbiased comparisons of iPSC-derived neurons
from different individuals or clones.