Chapter 3 Hormones and programmed cell death: insights from invertebrate studies

Publisher Summary This chapter deals with the use of invertebrates to study cellular and molecular aspects of neuronal death. The identified neurons in these animals that are well known for their stereotyped morphologies and patterns of connectivity may likewise have stereotyped, predictable fates. Thus, one can examine not only the changes that occur after degeneration begins, but also the events that precede death. Much of this work has been done on insects, in which neuronal death plays a prominent role both during embryogenesis and at metamorphosis. The neurons that die during the latter period include both immature cells and mature, functioning neurons that are used during larval life but then discarded. The occurrence of cell death as part of metamorphosis means that these events have come under the control of the hormones that regulate metamorphosis. Besides being able to manipulate the timing of cell death by endocrine manipulations, hormones have also provided useful tools for probing cellular interactions in the degeneration response.