2010-03-01
For a long time, it has been assumed that a certain subtype of dopamine neuron is critical for repairing motor function after cell transplantation in the brain affected by Parkinson’s disease. But it hasn’t been proven – until now.
In a new paper published in the scientific journal Brain, Ph.D. student Shane Grealish and co-authors show that the so-called A9 dopamine neurons are essential for graft-mediated recovery in tests on motor performance in a rodent model of Parkinson’s disease.
The death of dopamine-producing nerve cells in the midbrain is the leading cause of motor dysfunction in Parkinson’s disease. Replacing the missing neurons through transplantation of foetal tissue is an effective means to restore motor function in animal models of the disease, and also in patients with Parkinson’s disease.
These transplants contain two subtypes of dopamine neurons, called A9 and A10 neurons. The A9 neurons control motor function and are the ones that degenerate first in the disease progression, while the A10 neurons are known to be involved in the reward system. However, it has not been known until now which is mediating the recovery seen after grafting.
The authors have compared grafting experiments where grafts either lacked A9 neurons or had a typical A9/A10 composition. Results from behavioural experiments show that only animals that received grafts containing A9 neurons showed recovery in tests on motor performance.
– We already know that only the midbrain dopamine neurons can repair the brain in Parkinson’s disease, and now we have shown that a subtype of these neurons is most effective, says Shane Grealish.
If the A9 neurons are the first to degenerate in Parkinson’s disease, and impaired motor function is the first symptom, isn’t it obvious that the A9 neurons are the ones needed to restore motor function?
– Sure, it’s the most logical thing. But you can always be surprised in science, says Shane Grealish.
The paper is titled The A9 dopamine neuron component in grafts of ventral mesencephalon is an important determinant for recovery of motor function in a rat model of Parkinson’s disease. Authors: Shane Grealish, Marie E. Jönsson, Meng Li, Deniz Kirik, Anders Björklund and Lachlan H. Thompson.
Page Manager: Christel Thunell
Last modified: 2010-03-01
