Ralph's SCN transplantation study not only showed the role of the SCN, but it also showed the ability of a neural transplant to restore lost function. This same procedure is being explored as a treatment for neurodegenerative diseases. A study conducted in 2020 explored whether the transplantation of functional tissue from induced-pluripotent stem cells could restore function for a patient suffering from Parkinson’s disease. After confirming that the graft successfully survived, they found that over the course of two years the patient’s symptoms improved or remained constant. It is worth mentioning that this was only conducted in one patient. A recent meta-analysis (2022) of neural transplantation studies showed that replacing dopamine-producing cells with stem-cell derived equivalents is not only safe for patients but can improve motor function and daily living ability. Another study similar to Dr. Ralph’s work includes work done in 2014 which showed that transplantation of interneurons led to the restoration of memory and cognitive function in an Alzheimer’s disease mouse model In particular, the transplantation of inhibitory interneurons shed light on the role inhibition plays in generating normal function through interplay with excitatory neurons.
