NPY and Parkinson disease: It has been shown thatthe loss of the nigrostriatal dopamine pathway led to a significantincrease in the number of NPY-expressing cells in the striatum inanimal.83 Moreover, NPY demonstrated interactionsbetween glutamate and dopamine-containing neurons.84 It has been illustrated that the NPY protects dopamineneurons by inhibiting the release of glutamate in PD.