Download Directed Differentiation of Human Induced Pluripotent Stem

Directed Differentiation of Human Induced Pluripotent Stem Cells into Medial Ganglion Eminence
Progenitors Produce Functionally Active Neurons
Nathan N. Ng
Mentor: Diane O'Dowd
Genetic epilepsy with febrile seizures plus (GEFS+) is an autosomal dominant disorder that can be caused by
many different point mutations in the Nav1.1 voltage-gated sodium channel. Our lab has used a Drosophila
K1270T knock-in model and discovered a conditional gain-of-function alteration in sodium channels that
reduces the excitability of GABAergic neurons. To determine whether this mutation causes similar changes in
sodium channels and excitability in human neurons, we generated induced pluripotent stem cells (iPSCs) lines
from three siblings, two with the GEFS+ K1270T mutation and one without (Control). In our initial studies
Control iPSCs were used to derive expandable lines of neural stem cells (NSCs). However, when the NSCs
were differentiated into neurons using standard procedures, only 10% of the cells examined were capable of
firing action potentials and even fewer expressed GABA by 3–5 weeks. Additionally, there was significant
heterogeneity in the degree of functional differentiation from plating to plating. Therefore we experimented
with a recently published strategy for directed differentiation of iPSCs into medial ganglionic eminence
(MGE) progenitors that had been shown to enrich cultures for GABAergic neurons. Three weeks after
plating MGE progenitors onto mouse astrocyte feeder layers, approximately 28% of the MGE derived
neurons arising from Control iPSCs were GABAergic. Nearly all recorded cells were capable of firing action
potentials, with evidence of GABAergic and/or glutamatergic synaptic inputs. This differentiation protocol
will also be useful in determining how other genetically induced neurological disorders affect neuronal
maturation and function, facilitating development and testing of novel therapies.