By: David Warmflash
In the previous post, we discussed Parkinson disease as a gene therapy candidate with emphasis on the idea that standard therapies, while initially very helpful, lose effectiveness over time as affected brain areas degenerate.
When it comes to movement control, basal ganglia pathways are similar to an autopilot system, but not the kind of autopilot that can be turned off when malfunctioning in a simple aircraft. Rather, the pathways are like computer controlled systems of a complex aircraft that the pilot cannot fly manually. When dopamine is deficient—or when there’s a low ratio of dopamine versus another neurotransmitter called acetylcholine—a chain of events shifts automatic movement control from what’s called the direct pathway to a cruder circuit called the indirect pathway. Think of it as a secondary, cruder computer system taking over when the primary autopilot cuts out. The rudder and ailerons still work, but not with the usual finesse. The aircraft starts shaking and the pilot has to work harder to keep flying straight. Continue reading