As TH acts as the rate-limiting enzyme of catecholamine biosynthesis, this rat line has, therefore, been engineered to express Cre in catecholaminergic neurons, including dopaminergic ones, that are affected progressively during neurodegenerative diseases such as PD, and has, therefore, become particularly useful for researching the pathological mechanisms concerning PD. The gene discussed is TH; the disease is neurodegenerative disease.