From the Labs: Biotechnology

Rerouting Brain Circuits with Implanted Chips
A chip being tested in monkeys could one day reconnect areas of a damaged brain

Source: “Long-Term Motor Cortex Plasticity Induced by an Electronic
Neural Implant”
Andrew Jackson et al.
Nature 444(7115): 56-60

RESULTS: Researchers from the University of Washington in Seattle showed for the first time in live animals that an implantable device could record signals from one part of the brain and transmit them to another part, reshaping neural connections in the process.

WHY IT MATTERS: In stroke and spinal­-cord injuries, neural circuits that mediate language or movement may be damaged, leaving patients with profound disabilities. The Washington research is a significant first step in developing neural prosthetics that can help bridge broken connections.

METHODS: Tiny wire electrodes were surgically implanted into a monkey’s motor cortex. (Neurons in this area are active when an animal makes a voluntary movement.) The wires record the activity of nearby cells and relay their signals to a small printed circuit board for amplification and processing. The neural activity is converted to electric pulses, which stimulate cells at a neighboring motor-cortex site. The entire apparatus, about half the size of a deck of cards, is encased in titanium and attached to the monkey’s head, where it doesn’t interfere with the animal’s normal daily activities.

NEXT STEPS: Project leader ­Eberhard Fetz and his colleagues hope to show that a similar device could transmit neural signals from the brain directly to the spinal cord or to a ­muscle, bypassing areas of neurological injury. The researchers have shown that electrically stimulating certain cells in the spinal cord can elicit specific movements, such as grasping.

Wine Component Boosts Exercise Capacity in Mice
Resveratrol allows treated mice to run for twice as long as untreated ones

Source: “Resveratrol Improves Mitochondrial Function and Protects against Metabolic Disease by Activating SIRT1 and PGC-1a”
Marie Lagouge et al.
Cell online, November 16, 2006

RESULTS: Researchers at France’s University Louis Pasteur, Strasbourg, and at Sirtris Pharmaceuticals have shown that resveratrol, a chemical component of red wine that has already been linked to longevity, protects mice against diet-induced obesity and insulin resistance and boosts their endurance, allowing them to run for twice as long as untreated animals before becoming exhausted. The researchers found that mice treated with resveratrol also had large, highly active mitochondria, the subcellular structures that convert nutrients into energy in almost all plants and animals. This effect was linked to activation of a gene called SIRT1, the mammalian equivalent of a gene known to influence life span in yeast.

WHY IT MATTERS: The findings may indicate the mechanism behind resveratrol’s life-extending effects: activating SIRT1 to boost metabolic function. If scientists can understand how to regulate the biochemical pathway that causes aging, they may be able to design drugs that can stop the diseases of old age.

METHODS: Mice fed a high-fat diet were given high doses of resveratrol (either 200 or 400 milligrams per kilogram of body weight, or the equivalent of about 8,000 to 16,000 glasses of red wine). The researchers then tested the resting metabolism, exercise capacity, and insulin sensitivity of the mice. They also used electron microscopy to study the size of the mice’s mitochondria and calculated differences in the expression of mitochondria-related genes in treated and nontreated mice.

NEXT STEPS: Sirtris Pharmaceuticals is conducting a clinical trial of a resveratrol­-like compound intended to treat type II diabetes.