Taken together with the observation of the close correlation between the dynorphin B peak intensity from MALDI IMS and dynorphin B immunoreactivity in the same animals (Fig. 8C; p<0.05, R = 0.73) present convincing evidence that the dynorphin B neuropeptide levels are increased in animals with severe dyskinesia. The gene discussed is PDYN; the disease is drug-induced dyskinesia.