While the human brain and nervous system are wired with hundreds of billions of nerve cells, or neurons, sea slugs can get by with tens of thousands. Ironically, sea slugs reveal a lot about the chemistry of the human brain and nervous system. In fact, they are ideal as study subjects for research on learning, memory, and how neurons control behavior. With support from the National Science Foundation, analytical chemist Jonathan Sweedler and his team at the University of Illinois are working to develop new measurement tools that enable insights into the function of individual cells in the central nervous systems of slugs and other animals in order to uncover novel neurochemical pathways. Part of the National Science Foundation Series “Science Nation.”