Brain-on-a-chip melds the animate with the inanimate

17 Jun 2002

Researchers have grown circuits made of brain cells on a base of silicon. They hope their technique could lead to new ways of studying the effects of drugs on the brain without resorting to animal testing, and perhaps allow computer scientists to build machines that use neurons in place of transistors.

While researchers have managed to attach neurons to silicon outside the body, they have never been able to induce these nerve cells to mature and grow normally. Richard Potember of Johns Hopkins University says he has found a way around this problem. Working with Mieko Matsuzawa, Potember coated silicon slides with a thin layer of specially designed molecules. One end of these long, thin molecules is chemically attracted to silicon, so the molecules naturally arrange themselves like a dense thicket of hairs growing out of the silicon surface.

The outer tips of these hairs were crafted to attract a second type of molecule which neurons would grow on. For this molecule, Potember chose the active sites from proteins called nerve growth factors, which bind to neurons and signal them to grow. Once the growth-stimulating molecules were in place, Potember and Matsuzawa placed immature neurons on the coated glass slides. The neurons developed normally, sending out axons and dendrites, and making connections with other neurons. Potember presented the work at the American Chemical Society meeting in New Orleans this week.