The construction of complex man-made objects--a car, for example, or even a pizza--almost invariably entails what are known as "top-down" processes, in which the structure and order of the thing being built is imposed from the outside (say, by an automobile assembly line, or the hands of the pizza maker).

Scientists at the California Institute of Technology (Caltech) have trained computers to automatically analyze aggression and courtship in fruit flies, opening the way for researchers to perform large-scale, high-throughput screens for genes that control these innate behaviors.

A tiny genetic mutation is the key to understanding why nicotine--which binds to brain receptors with such addictive potency--is virtually powerless in muscle cells that are studded with the same type of receptor. That's according to California Institute of Technology (Caltech) researchers, who report their findings in the March 26 issue of the journal Nature.

Tiny, lightweight fruit flies need to know when it's windy out so they can steady themselves and avoid being knocked off their feet or blown off course. But how do they figure out that it's time to hunker down? Flies have evolved a specialized population of neurons in their antennae that let them know not only when the wind is blowing, but also the direction from which it is coming.

For the tiny soil-dwelling nematode worm Caenorhabditis elegans, life is usually a situation of feast or famine. Researchers at the California Institute of Technology (Caltech) have found that this worm has evolved a surprisingly optimistic genetic strategy to cope with these disparate conditions--one that could eventually point the way to new treatments for a host of human diseases caused by parasitic worms.

By listening in on the chatter between neurons in various parts of the brain, researchers from the California Institute of Technology (Caltech) have taken steps toward fully understanding just how memories are formed, transferred, and ultimately stored in the brain--and how that process varies throughout the various stages of sleep. 

A quartet of studies by researchers at the California Institute of Technology (Caltech) highlight a special feature on gene regulatory networks recently published in the Proceedings of the National Academy of Sciences (PNAS).

Using novel imaging, labeling, and data-analysis techniques, scientists from Caltech have been able to visualize, for the first time, large numbers of cells moving en masse during some of the earliest stages of embryonic development. The findings not only provide insight into this stage of development--called gastrulation--but give a more general glimpse at how a living organism choreographs the motions of thousands of cells at one time.

Scientists from the California Institute of Technology (Caltech) have created images of the heart's muscular layer that show, for the first time, the connection between the configuration of those muscles and the way the human heart contracts. More precisely, they showed that the muscular band--which wraps around the inner chambers of the heart in a helix--is actually a sort of twisting highway along which each contraction of the heart travels.