21. Parkinson's symptoms occur when dopamine-producing neurons in the substantia nigra of the brain begin to die. 22. The structural similarity between the substantia nigra and globus pallidus was noted by Mirto in 1896. 23. The substantia nigra is a small midbrain area that forms a component of the basal ganglia. 24. However, with this treatment, the number of substantia nigra neurons decrease so it becomes less efficient. 25. Parkinson's disease is characterized by the death of dopaminergic neurons in the substantia nigra pars compacta. 26. The same for the substantia nigra pars reticulata. 27. Parkinson's occurs when specialized cells die in a portion of the brain called the substantia nigra . 28. The substantia nigra is located in the midbrain. 29. Parkinson's disease is a neurodegenerative disease affecting the substantia nigra , a component of the basal ganglia. 30. Doctors blame a loss of cells in an area of the brain called the substantia nigra .
