RNA-seq of laser captured oculomotor, cervical and lumbar spinal motor, and Onufs nucleus motor neurons in post mortem material of control human subjects

Oculomotor neurons, which regulate eye movement, are resilient to degeneration in the lethal motor neuron disease amyotrophic lateral sclerosis (ALS). It would be highly advantageous if motor neuron resilience could be modeled in vitro. Towards this goal, we generated a high proportion of oculomotor neurons from mouse embryonic stem cells through temporal overexpression of Phox2a in neuronal progenitors. We demonstrate, using electrophysiology, immunocytochemistry and RNA sequencing, that in vitro generated neurons are bona fide oculomotor neurons based on their similarity to their in vivo counterpart in rodent and man. We also show that in vitro generated oculomotor neurons display a robust activation of survival-promoting Akt signaling and are more resilient to the ALS-like toxicity of kainic acid than spinal motor neurons. Thus, we can generate bona fide oculomotor neurons in vitro which display a resilience similar to that seen in vivo. A total of 39 samples were analyzed. Each sample is consists of between 30-120 laser-captured motor neurons from post-mortem human tissue. Samples are divided over 3 groups: lumbar/cervical spinal cord motor neurons (n=12), oculomotor neurons (n=20) and motor neurons of Onuf's nucleus in the sacral spinal cord (n=7).