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Dmitri Chklovskii wants to know if neural networks follow the same design logic as microchips.
His colleagues dissect the flies' brains, 50 nanometers at a time. “It's like slicing prosciutto,” he says. Extremely thin prosciutto—1/1,000th the thickness of a human hair. Each slice reveals a new layer of neurons and synapses, which are carefully photographed with an electron microscope. Later, Chklovskii's team uses computers to trace each neuron's axon and dendrites as they snake through the brain.
Chklovskii is using computer algorithms to trace neural networks, and he thinks the principle of economy underlying microchip design may also govern the “wiring” of a neural network. Nature and microchip engineers may be working from the same playbook.
With its neuroscience focus and interdisciplinary character, Janelia Farm is a perfect place for Chklovskii, who was trained as a theoretical physicist and is now working to understand how the brain functions. “I consider myself a neurobiologist because I publish in neurobiology journals and go to neurobiology conferences,” he says. “But I try to think like an engineer.”
What does it mean to think like an engineer? In some circles, engineering is linked to the quest to build things and solve practical problems—for example, putting a man on the moon. ABET, Inc., formerly known as the Engineers' Council for Professional Development, has defined the discipline as: the creative application of scientific principles to design or develop structures, machines, apparatus, or manufacturing processes... By that credo, engineering serves not to expand the boundaries of knowledge but rather as the link between existing scientific discovery and technological benefit.
But Chklovskii and others see engineering as a broader set of ideals: simplicity, practicality, systematic thinking, and the idea that understanding a thing—or a process or a cell—isn't ensured until that thing can be built.
The line between science and engineering is blurring as engineers and tool makers set their sights—and their engineering minds—on unanswered biological questions, both as a means to solve practical problems and because they too are fascinated by the basic nature of life. And biomedical researchers, those who are after practical solutions to disease and those who seek to push the boundaries of knowledge, are reaching over and borrowing techniques and ideals from the engineers' toolbox.
Photo: Paul Fetters