A student of Nils-?ke Hillarp, Lars Olson obtained his PhD at the Karolinska Institute in 1970. He has held his position as professor of neurobiology at Karolinska Institute since 1986, has served 11 years as department chairman, and is a member of the Karolinska Nobel assembly and the board of the Swedish Brain foundation. Throughout his career, Olson has studied development, nerve growth factors, degeneration and regeneration and repair in the nervous system. Two main focuses of the Olson group are spinal cord injury and Parkinson's disease. For his contributions, Olson has received several awards and honors. Olson and collaborators developed cell grafting strategies in animal models of Parkinson's disease and participated in the first attempts at grafting tissue in patients with Parkinson's disease. Recently, Olson's team has contributed to the understanding of genetic risk factors in Parkinson's disease, and, together with Dr. Nils-Goran Larsson's team at Karolinska Institutet developed a toxin-free, genetic mouse model of the disease, based on known effects of toxins and theories about how mutations in certain genes that cause rare forms of Parkinson's disease may function. The new animal model may help understanding disease-causing mechanisms and may become useful for tests of novel neuroprotective drug treatments.