If you, or someone you know, has Parkinson’s disease, mental health issues, or other neurological disorders, medication can often help. The bulk of these medications have been established based on the work of neuroscientist Paul Greengard (Figure 1) from the Rockefeller University, who worked out just how the brain responds to neurotransmitters—the chemicals that help the brain signal. The bulk of what most neuroscientists know today about neurotransmission, and specifically the dynamics of slow synaptic transmission, is predicated on the work of Paul Greengard. The full interview, with many more stories about his seminal research discoveries and his competitive streak in potato sack races, can be seen on the JCI website, http://www. jci. org/kiosk/cgm. JCI: Can you tell us a little bit about your path towards becoming a scientist? Greengard: I grew up in New York City. My mother died giving birth to me, and then my father remarried when I was one year old. He was a businessman; she was a housewife. They were both very anti-intellectual, and so I did not get the bug for doing scientific research at home. It was a very anti-intellectual atmosphere at home and to a certain extent, possibly a rebellion against that, was what made me very committed to science. They did not want me to go to college, but fortunately I had served in the Second World War, and was able to get through college on the GI Bill. JCI: What did you study? Greengard: In college I studied mathematics and physics. After that, I was going to go to graduate school, and I had been planning to work in theoretical physics. But this was almost immediately after the dropping of the atomic bombs on Hiroshima and Nagasaki, and I felt that was not an area I wanted to be really involved in because I thought there were better ways of spending my life than trying to destroy mankind. I had heard about the nascent field of medical physics or biophysics. And at that time, there were two biophysics departments in the country. One was at the Lawrence Laboratory in Berkeley, which was involved in doing radioisotope studies in biology and the other one was the Department of Biophysics at Penn which was involved in studying the electrical properties of nerve cells.