Hormones such as testosterone and estrogen help sculpt the nervous system throughout life, from early development through old age. Around the time of birth, these hormones can decide which neurons die off (or live) preferentially in males and which die off (or live) more in females. Later, in adulthood, testosterone no longer determines neuronal survival, but does regulate aspects of neuronal morphology, including cell size. Work outlined in this book explores the role of testosterone and the Bcl-2 family of proteins in regulating both neuronal death during development and neuronal morphology...