New Stem Cell Approach Targets Dopamine Loss in Parkinson's Patients: Study

What if Parkinson's disease could be treated not just by easing symptoms-but by replacing the very cells that are lost? Scientists at Keck Medicine of USC are testing whether implanted stem cells can restore dopamine production in the brain, potentially improving movement and altering the course of the disease.

Parkinson’s disease is a progressive neurological disorder affecting more than one million people in the United States. It occurs when dopamine-producing neurons gradually die, particularly in brain regions that control movement. Dopamine is essential for coordinating smooth, controlled muscle activity. As levels decline, patients develop tremors, stiffness, slowed movements and balance problems. Current treatments—such as dopamine-replacing medications—can reduce symptoms but do not stop the underlying neurodegeneration.

In this early-phase clinical trial, researchers are implanting laboratory-engineered induced pluripotent stem cells (iPSCs) directly into the brain. Unlike embryonic stem cells, iPSCs are created by reprogramming adult cells, such as skin or blood cells, back into a flexible state. These cells are then guided in the lab to mature into dopamine-producing neurons.

During the procedure, neurosurgeons create a small opening in the skull and use MRI guidance to precisely deliver the engineered cells into the basal ganglia—the brain region responsible for movement coordination. The goal is for the transplanted cells to survive, integrate with surrounding brain tissue and begin producing dopamine naturally.

Participants are monitored closely for 12 to 15 months after surgery to evaluate motor function improvements and assess safety. Doctors are watching for potential side effects, including dyskinesia (involuntary excessive movements), immune reactions or infection. Long-term follow-up will continue for up to five years to determine whether the therapy provides sustained benefit.

Researchers hope that restoring dopamine at its source could “jump-start” the brain’s own signaling systems. While still experimental, this regenerative approach represents a shift from symptom management toward cellular repair—offering new hope for slowing progression and improving quality of life in Parkinson’s disease.

REFERENCE: University of Southern California - Health Sciences. "Doctors implant dopamine-producing stem cells in Parkinson’s patients." ScienceDaily. ScienceDaily, 20 February 2026..