Exploring neurogenesis in crustaceans

Plasticity, learning and memory, and neurological disease are exciting topics for students. Discussion around these subjects often results in the consideration of the role of neurogenesis in development, or its involvement in a potential cure for some diseases. We have therefore designed a lab that allows students to experimentally examine how the rate of neurogenesis can be altered by environmental factors. Neuronal cell division in crayfish is identified with fluorescently-labeled BrdU and quantified using conventional or confocal microscopy. Recent studies indicate a conservation of mechanisms that control neurogenesis from insects and crustaceans to mammals. Yet the use of invertebrate models such as crayfish or lobsters has advantages over mammalian models. Invertebrate nervous systems have a simpler organization and larger, identifiable neurons - qualities that make such preparations easier for students to manage. This lab offers many opportunities for student designed experiments and discovery-oriented learning by exploring factors that regulate neurogenesis such as environment, hormones and light. This article illustrates our first experience with the lab, using an experiment designed by our students. We include ideas for expansion of this model and suggestions for avoiding potential pitfalls. It is written in the form of a scientific paper, reporting on a single student experiment, to aid as a teaching tool for future classes.