It is of interest as a precursor to the monoaminergic neurotoxin MPP+, which causes permanent symptoms of Parkinson's disease by destroying dopaminergic neurons in the substantia nigra of the brain.

Once inside the brain, MPTP is metabolized into the toxic cation 1-methyl-4-phenylpyridinium (MPP+)[5] by the enzyme monoamine oxidase B (MAO-B) of glial cells, specifically astrocytes.

MPP+ kills primarily dopamine-producing neurons in a part of the brain called the pars compacta of the substantia nigra.

Calbindin regulates the availability of Ca2+ within the cell, which is not the case in SNc neurons due to their high-calcium-dependent autonomous pacemaker activity.

The direction of complex movement is based from the substantia nigra to the putamen and caudate nucleus, which then relay signals to the rest of the brain.

This pathway is controlled via dopamine-using neurons, which MPTP selectively destroys, resulting, over time, in parkinsonism.

The National Institute of Mental Health found traces of MPTP and other pethidine analogs in his lab.

[12] The neurologist J. William Langston in collaboration with NIH tracked down MPTP as the cause, and its effects on primates were researched.

[17] Knowledge of MPTP and its use in reliably recreating Parkinson's disease symptoms in experimental models has inspired scientists to investigate the possibilities of surgically replacing neuron loss through fetal tissue implants, subthalamic electrical stimulation and stem cell research, all of which have demonstrated initial provisional successes.

It was shown that the pesticide and insecticide rotenone causes Parkinsonism in rats by killing dopaminergic neurons in the substantia nigra.