By David F. Salisbury Critical new data on a complex enzyme that lies at the crossroad between cell suicide and tumor suppression has opened a promising new front in the battle to find effective treatments for stroke and cancer. Scientists at Vanderbilt University and Northwestern University have determined the three-dimensional structure of a critical region of Death Associated Protein Kinase (DAPK) and created a quantitative assay capable of measuring its activity.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 19: Language and Lateralization
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 15: Language and Lateralization
Link ID: 1137 - Posted: 12.08.2001

by Dan Ferber It's no secret that sex hormones mess with the mind and alter behavior, and researchers have known, too, that they alter the shape of specific brain cells. But despite the logical connection, researchers have struggled to prove that the two effects are linked. Janis Weeks' team has shown precisely how steroid hormones affect individual neurons in a caterpillar with a simple nervous system, causing profound changes that help the caterpillar become a moth. The results, presented here in a special lecture, reveal how steroid hormones might affect other animal brains, including our own. Weeks and her colleagues at the University of Oregon study the simple nervous system of a caterpillar called the tobacco hornworm that has a body the length of a human hand. Like other caterpillars, it transforms into a pupa and then an adult moth, and entomologists have long known that a steroid hormone called 20-hydroxyecdysone (20E) triggers each step of the metamorphosis. © Elsevier Science Limited 2000

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 4: Development of the Brain; Chapter 8: Hormones and Sex
Link ID: 1062 - Posted: 11.27.2001

by Kirsten C. Sadler Recent studies indicate that during apoptosis engulfing cells do not simply dispose of suicidal cells but actively participate in killing them. Even more striking is the observation that a small percentage of target cells may show some morphological signs of apoptosis but then apparently change their mind and return from the brink of death. Once a cell has received a death signal and makes the molecular decision to commit suicide, the killing is carried out in a stepwise fashion by, in most but not all cases, members of the Bcl-2 family, release of cytochrome c and other factors from the mitochondria and, in all cases, activation of the caspase family of proteases. Caspases dismantle the cell and also activate other proteases to aid in the execution. Once the deed is done, the dead cell's neighbors engulf the cell corpse. Some cells return from the brink of death. © Elsevier Science Limited 2000

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 4: Development of the Brain
Link ID: 1041 - Posted: 11.27.2001