Which pathway is associated with Parkinson's disease due to dopamine damage?

The nigrostriatal pathway is primarily responsible for the coordination of movement and is heavily involved in the regulation of motor control. This pathway connects the substantia nigra, a region of the brain that produces dopamine, with the striatum, which plays a crucial role in the initiation and regulation of voluntary movement. In Parkinson's disease, dopamine-producing neurons in the substantia nigra degenerate and die, leading to a significant decrease in dopamine levels in the nigrostriatal pathway. This depletion of dopamine is directly linked to the characteristic motor symptoms of Parkinson's, such as tremors, stiffness, and bradykinesia (slowness of movement).

While the other pathways listed can influence behavior and cognition, they are not primarily responsible for the motor symptoms associated with Parkinson's disease. The mesolimbic pathway is mainly involved in reward processing and motivation, the mesocortical pathway affects cognitive functions and emotional regulation, and the brainstem pathway is related to autonomic functions and basic life support. Thus, the nigrostriatal pathway's direct involvement with dopamine and movement distinctly aligns it as the pathway associated with the motor deficits seen in Parkinson's disease.