The Immune System: Imaged at Last

HHMI Bulletin | February 2006

If the thought of invasive medical procedures makes you queasy, HHMI investigator Owen N. Witte points out that “there’s a noninvasive trend in medical diagnosis—to measure things inside the body without having to stick tubes in a patient or do an operation.” Witte, a researcher at the University of California, Los Angeles, has recently furthered this trend, leading a team from three medical institutions to develop a noninvasive technique based on positron emission tomography (PET). The scientists captured three-dimensional views of one body component never before seen from the outside—the immune system.
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The Fate of Brain Cells

HHMI Bulletin | December 2005

A fountain of youth springs from within the brain of every mammal, report HHMI investigator Alexandra L. Joyner and her former postdoctoral associate Sohyun Ahn in the October 6, 2005, issue of Nature. No, the two researchers haven’t unlocked the secret to immortality. But their discovery of a method to visualize an elusive population of stem cells that has the potential to regenerate nerves and other brain cells may explain how certain regions of the brain rejuvenate themselves. Moreover, the findings may allow researchers to tap the revitalizing powers of stem cells for repairing injured and diseased brain tissue.
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DReAMM Scheme

HHMI Bulletin | December 2005

Combining high-resolution serial electron microscopic tomography, neuroelectrophysiological measurements, mathematical modeling, and computer graphics, a multi-institution team led by HHMI investigator Terrence J. Sejnowski at the Salk Institute for Biological Studies has overturned a half-century’s dogma in neurobiology.
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Tracking a Perpetrator Gene

HHMI Bulletin | September 2005

On May Day 1999, Jennifer Chamberlin,* a 43-year-old secretary in the Midwest, stayed home to recuperate from back surgery and spend time with her three daughters, on spring break from school. Walking into her kitchen, Jenn fainted and fell to the floor. She soon regained consciousness but never returned to her normal self.
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Also read Separated at Birth?

It all began some 30 years ago, when the two physician-scientists were 20-some-thing medical students at Duke University. Being a year apart, “we didn’t know each other at all,” Ginsburg recounts, “but we discovered just a couple of years ago that we had dated the same girl!”

Protein Disposal: Gumming Up the Works

HHMI Bulletin | September 2005

For a cell, destroying proteins is as essential as building them. The job of mincing proteins is performed by enzymatic machines called proteasomes. “Proteasomes affect almost all biological processes in the cell,” Verma says. By their deliberate destruction of regulatory proteins, they orchestrate activities from cell division to cell death. read in full issue (pdf)

Toddler Hits Its Stride

HHMI Bulletin | March 2005

Meet Toddler, a walking robot that mimics the human gait.  Created by computer engineer Russ Tedrake in the lab of computational neuroscientist and HHMI investigator H. Sebastian Seung at MIT, Toddler uses customized learning software to teach itself to walk in less than 20 minutes.  The robot “doesn’t walk too much like a human, but we think it learns like a human,” Tedrake says. read in full issue (pdf)