People with Parkinson’s disease that received a growth factor (GDNF) experienced a 100% improvement in dopamine uptake in a key brain region involved in the disease compared to the placebo group which did not experience any change. The participants that received GDNF also showed moderate to large improvements in symptoms.

The GDNF was implanted into the brain using robot-assisted neurosurgery. This delivery system allowed a high flow rate of GDNF infusions that were administered every four weeks.

Parkinson’s disease leads to a substantial decrease in dopamine-producing neurons in the brain. These neurons are important for motor control and other cognitive functions.

Several animal studies have identified GDNF as an important regulator of dopamine neurons in the brain. Interestingly, animal studies have also shown that GDNF is produced in the brain after acute and long-term exercise. Exercise has been shown to improve Parkinson’s disease symptoms in several clinical trials.