Rodent Models of Parkinsons Disease

The cardinal symptoms of Parkinson’s disease are rigidity, akinesia, and tremors. Secondary symptoms include postural abnormalities and neuropsychiatric disturbances such as depression, cognitive disorders, and apparent apathy (Barbeau, 1979 ; Schultz, 1984 ; Marsden et al., 1975 ). The basic neuropathology of Parkinson’s disease involves degeneration of the heavily pigmented cells of the substantia nigra, locus ceruleus, and other brainstem nuclei (Hornykiewicz, 1972 ; Barbeau, 1979 ; Hornykiewicz and Kish, 1986 ). A markedly decreased concentration of dopamine (DA) and its metabolites is the main neurochemical change in the disease, although other neurotransmitters such as norepinephrine (NE) and serotonin (5-hydroxy-tryptamine, 5-HT) are also reduced (Hornykiewicz, 1972 ; Schultz, 1984 ; Agid and Javoy-Agid, 1985 ; Hornykiewicz and Kish, 1986 ).