Thearpies is that inidiopathic parkinsionism

The pathophysiologic basis for these thearpies is that inidiopathic parkinsionism, dopaminergic neurons in the substantianigra that normally inhibit the output of GABAergic cells in thecorpus striatum are lost.

I dont understand this sentence from my book. Do dopaminergicneurons inhibit gaba is that what its saying in normal physiologyor is that the pathophysiology