Headlines from the Division of Biology

June 26, 2009 - Caltech researchers studying the nervous control of nematode mating behavior have produced video footage of a male worm preparing to mate with a hermaphrodite. Allyson Whittaker, a senior research fellow in biology, and Paul Sternberg, the Thomas Hunt Morgan Professor of Biology, investigated the role of the excitatory neurotransmitter acetylcholine in regulating tail muscles to achieve an exploratory embrace. The video shows an intimate moment between two nematodes of the species Caenorhabditis elegans.

June 17, 2009 - Bacteria are mostly known for making you sick—causing deadly diseases such as pneumonia, syphilis, cholera, tuberculosis, and meningitis. But not all microbes are malicious. In fact, your bowels bustle with about a hundred trillion bacteria—that's 10 times more microorganisms than you have cells in your body. In a recent article in Engineering & Science magazine, author Marcus Woo explains that these bugs aren't just harmless; they may be crucial for your health. Click here to learn more.

June 11, 2009 - The twirling seeds of maple trees spin like miniature helicopters as they fall to the ground. Because the seeds descend slowly as they swirl, they're carried aloft by the wind and dispersed over great distances. Just how the seeds manage to fall so slowly, however, has mystified scientists. In research published in the June 12 Science, researchers from Wageningen University in the Netherlands and Caltech describe the aerodynamic secret of the enchanting swirling seeds.

May 29, 2009 - Theta oscillations are a type of prominent brain rhythm that orchestrates neuronal activity in the hippocampus, a brain area critical for the formation of new memories. For several decades these oscillations were believed to be "in sync" across the hippocampus, timing the firing of neurons like a sort of central pacemaker. A new study conducted by researchers at Caltech argues that this long-held assumption needs to be revised. In a paper published in this week's issue of the journal Nature, the researchers showed that instead of being in sync, theta oscillations actually sweep along the length of the hippocampus as traveling waves.

May 19, 2009 - You can tell without looking whether you've been stuck by a pin or burnt by a match. But how? In research that overturns conventional wisdom, a team of scientists from Caltech and the University of California, San Francisco, have shown that this sensory discrimination begins in the skin at the very earliest stages of neuronal information processing, with different populations of sensory neurons—called nociceptors—responding to different kinds of painful stimuli. Their findings were published this week in the early online edition of the Proceedings of the National Academy of Sciences.